CN114642972B - Deboron reverse osmosis membrane and preparation method thereof - Google Patents
Deboron reverse osmosis membrane and preparation method thereof Download PDFInfo
- Publication number
- CN114642972B CN114642972B CN202011503729.2A CN202011503729A CN114642972B CN 114642972 B CN114642972 B CN 114642972B CN 202011503729 A CN202011503729 A CN 202011503729A CN 114642972 B CN114642972 B CN 114642972B
- Authority
- CN
- China
- Prior art keywords
- layer
- solution
- transition layer
- reverse osmosis
- functionalization
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000012528 membrane Substances 0.000 title claims abstract description 97
- 238000001223 reverse osmosis Methods 0.000 title claims abstract description 65
- 238000002360 preparation method Methods 0.000 title claims abstract description 46
- 230000007704 transition Effects 0.000 claims abstract description 84
- 239000002159 nanocrystal Substances 0.000 claims abstract description 52
- 239000001913 cellulose Substances 0.000 claims abstract description 48
- 229920002678 cellulose Polymers 0.000 claims abstract description 48
- 238000011033 desalting Methods 0.000 claims abstract description 44
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 38
- 238000010612 desalination reaction Methods 0.000 claims abstract description 36
- 229920000642 polymer Polymers 0.000 claims abstract description 34
- 239000000758 substrate Substances 0.000 claims abstract description 22
- 239000004952 Polyamide Substances 0.000 claims abstract description 12
- 229920002647 polyamide Polymers 0.000 claims abstract description 12
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 claims description 50
- 239000000178 monomer Substances 0.000 claims description 42
- 239000002904 solvent Substances 0.000 claims description 42
- 238000007306 functionalization reaction Methods 0.000 claims description 40
- 239000003054 catalyst Substances 0.000 claims description 32
- 229920002239 polyacrylonitrile Polymers 0.000 claims description 32
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 31
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 claims description 25
- 150000001412 amines Chemical class 0.000 claims description 23
- BAPJBEWLBFYGME-UHFFFAOYSA-N Methyl acrylate Chemical compound COC(=O)C=C BAPJBEWLBFYGME-UHFFFAOYSA-N 0.000 claims description 22
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 claims description 21
- 238000000034 method Methods 0.000 claims description 20
- 239000003431 cross linking reagent Substances 0.000 claims description 14
- 230000004048 modification Effects 0.000 claims description 14
- 238000012986 modification Methods 0.000 claims description 14
- JRMUNVKIHCOMHV-UHFFFAOYSA-M tetrabutylammonium bromide Chemical compound [Br-].CCCC[N+](CCCC)(CCCC)CCCC JRMUNVKIHCOMHV-UHFFFAOYSA-M 0.000 claims description 13
- -1 2-dibromomethyl-1, 3-dibromopropane Chemical compound 0.000 claims description 12
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 12
- 229910001868 water Inorganic materials 0.000 claims description 12
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 claims description 10
- 239000013067 intermediate product Substances 0.000 claims description 10
- 239000003607 modifier Substances 0.000 claims description 10
- WZCQRUWWHSTZEM-UHFFFAOYSA-N 1,3-phenylenediamine Chemical compound NC1=CC=CC(N)=C1 WZCQRUWWHSTZEM-UHFFFAOYSA-N 0.000 claims description 9
- 230000007062 hydrolysis Effects 0.000 claims description 9
- 238000006460 hydrolysis reaction Methods 0.000 claims description 9
- 229940018564 m-phenylenediamine Drugs 0.000 claims description 9
- RDOXTESZEPMUJZ-UHFFFAOYSA-N anisole Chemical compound COC1=CC=CC=C1 RDOXTESZEPMUJZ-UHFFFAOYSA-N 0.000 claims description 8
- YOCIJWAHRAJQFT-UHFFFAOYSA-N 2-bromo-2-methylpropanoyl bromide Chemical compound CC(C)(Br)C(Br)=O YOCIJWAHRAJQFT-UHFFFAOYSA-N 0.000 claims description 7
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 claims description 6
- 229920000875 Dissolving pulp Polymers 0.000 claims description 4
- 239000004695 Polyether sulfone Substances 0.000 claims description 4
- 230000003301 hydrolyzing effect Effects 0.000 claims description 4
- UZKWTJUDCOPSNM-UHFFFAOYSA-N methoxybenzene Substances CCCCOC=C UZKWTJUDCOPSNM-UHFFFAOYSA-N 0.000 claims description 4
- 229920002492 poly(sulfone) Polymers 0.000 claims description 4
- 229920006393 polyether sulfone Polymers 0.000 claims description 4
- 150000003384 small molecules Chemical class 0.000 claims description 4
- GEYOCULIXLDCMW-UHFFFAOYSA-N 1,2-phenylenediamine Chemical compound NC1=CC=CC=C1N GEYOCULIXLDCMW-UHFFFAOYSA-N 0.000 claims description 3
- CBCKQZAAMUWICA-UHFFFAOYSA-N 1,4-phenylenediamine Chemical compound NC1=CC=C(N)C=C1 CBCKQZAAMUWICA-UHFFFAOYSA-N 0.000 claims description 3
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 claims description 3
- 239000004696 Poly ether ether ketone Substances 0.000 claims description 3
- 239000001110 calcium chloride Substances 0.000 claims description 3
- 229910001628 calcium chloride Inorganic materials 0.000 claims description 3
- 229920002530 polyetherether ketone Polymers 0.000 claims description 3
- 239000004800 polyvinyl chloride Substances 0.000 claims description 3
- 229920000915 polyvinyl chloride Polymers 0.000 claims description 3
- LZZYPRNAOMGNLH-UHFFFAOYSA-M Cetrimonium bromide Chemical compound [Br-].CCCCCCCCCCCCCCCC[N+](C)(C)C LZZYPRNAOMGNLH-UHFFFAOYSA-M 0.000 claims description 2
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 claims description 2
- HTZCNXWZYVXIMZ-UHFFFAOYSA-M benzyl(triethyl)azanium;chloride Chemical compound [Cl-].CC[N+](CC)(CC)CC1=CC=CC=C1 HTZCNXWZYVXIMZ-UHFFFAOYSA-M 0.000 claims description 2
- CQEYYJKEWSMYFG-UHFFFAOYSA-N butyl acrylate Chemical compound CCCCOC(=O)C=C CQEYYJKEWSMYFG-UHFFFAOYSA-N 0.000 claims description 2
- VCJZTATVUDMNLU-UHFFFAOYSA-N dibromomethylbenzene Chemical compound BrC(Br)C1=CC=CC=C1 VCJZTATVUDMNLU-UHFFFAOYSA-N 0.000 claims description 2
- DDXLVDQZPFLQMZ-UHFFFAOYSA-M dodecyl(trimethyl)azanium;chloride Chemical compound [Cl-].CCCCCCCCCCCC[N+](C)(C)C DDXLVDQZPFLQMZ-UHFFFAOYSA-M 0.000 claims description 2
- XJWSAJYUBXQQDR-UHFFFAOYSA-M dodecyltrimethylammonium bromide Chemical compound [Br-].CCCCCCCCCCCC[N+](C)(C)C XJWSAJYUBXQQDR-UHFFFAOYSA-M 0.000 claims description 2
- SUPCQIBBMFXVTL-UHFFFAOYSA-N ethyl 2-methylprop-2-enoate Chemical compound CCOC(=O)C(C)=C SUPCQIBBMFXVTL-UHFFFAOYSA-N 0.000 claims description 2
- HQHJZSCJOXQOAY-UHFFFAOYSA-N 1-(dibromomethyl)-4-methylbenzene Chemical group CC1=CC=C(C(Br)Br)C=C1 HQHJZSCJOXQOAY-UHFFFAOYSA-N 0.000 claims 1
- 238000005271 boronizing Methods 0.000 claims 1
- 238000007493 shaping process Methods 0.000 claims 1
- 230000004907 flux Effects 0.000 abstract description 12
- 239000010410 layer Substances 0.000 description 220
- 239000000243 solution Substances 0.000 description 162
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 82
- 229910052796 boron Inorganic materials 0.000 description 30
- 238000002156 mixing Methods 0.000 description 30
- 239000012071 phase Substances 0.000 description 29
- VHYFNPMBLIVWCW-UHFFFAOYSA-N 4-Dimethylaminopyridine Chemical compound CN(C)C1=CC=NC=C1 VHYFNPMBLIVWCW-UHFFFAOYSA-N 0.000 description 28
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 26
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 24
- 238000003756 stirring Methods 0.000 description 22
- 239000004745 nonwoven fabric Substances 0.000 description 21
- 239000008367 deionised water Substances 0.000 description 19
- 229910021641 deionized water Inorganic materials 0.000 description 19
- 239000013535 sea water Substances 0.000 description 18
- 238000005406 washing Methods 0.000 description 18
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 15
- 238000010438 heat treatment Methods 0.000 description 15
- 239000011148 porous material Substances 0.000 description 15
- 239000004743 Polypropylene Substances 0.000 description 13
- 229920001155 polypropylene Polymers 0.000 description 13
- 239000003906 humectant Substances 0.000 description 12
- 229920000036 polyvinylpyrrolidone Polymers 0.000 description 12
- 239000001267 polyvinylpyrrolidone Substances 0.000 description 12
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 description 12
- 239000002585 base Substances 0.000 description 11
- 238000001035 drying Methods 0.000 description 11
- 239000000463 material Substances 0.000 description 10
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 9
- IMNFDUFMRHMDMM-UHFFFAOYSA-N N-Heptane Chemical compound CCCCCCC IMNFDUFMRHMDMM-UHFFFAOYSA-N 0.000 description 9
- 239000007864 aqueous solution Substances 0.000 description 9
- 230000015271 coagulation Effects 0.000 description 9
- 238000005345 coagulation Methods 0.000 description 9
- 239000000203 mixture Substances 0.000 description 9
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 8
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 8
- 239000004327 boric acid Substances 0.000 description 8
- 238000011068 loading method Methods 0.000 description 8
- 238000006116 polymerization reaction Methods 0.000 description 8
- QOSSAOTZNIDXMA-UHFFFAOYSA-N Dicylcohexylcarbodiimide Chemical compound C1CCCCC1N=C=NC1CCCCC1 QOSSAOTZNIDXMA-UHFFFAOYSA-N 0.000 description 7
- 230000008569 process Effects 0.000 description 7
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 6
- 230000002776 aggregation Effects 0.000 description 6
- 238000004220 aggregation Methods 0.000 description 6
- 238000001816 cooling Methods 0.000 description 6
- 238000001914 filtration Methods 0.000 description 6
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 6
- 238000001132 ultrasonic dispersion Methods 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 5
- 239000011248 coating agent Substances 0.000 description 5
- 238000000576 coating method Methods 0.000 description 5
- 239000002131 composite material Substances 0.000 description 5
- 239000012510 hollow fiber Substances 0.000 description 5
- 239000012456 homogeneous solution Substances 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 description 4
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 4
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 4
- UWCPYKQBIPYOLX-UHFFFAOYSA-N benzene-1,3,5-tricarbonyl chloride Chemical compound ClC(=O)C1=CC(C(Cl)=O)=CC(C(Cl)=O)=C1 UWCPYKQBIPYOLX-UHFFFAOYSA-N 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 230000007935 neutral effect Effects 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- CNPVJWYWYZMPDS-UHFFFAOYSA-N 2-methyldecane Chemical compound CCCCCCCCC(C)C CNPVJWYWYZMPDS-UHFFFAOYSA-N 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 3
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 description 3
- 239000002202 Polyethylene glycol Substances 0.000 description 3
- 239000004372 Polyvinyl alcohol Substances 0.000 description 3
- FYXKZNLBZKRYSS-UHFFFAOYSA-N benzene-1,2-dicarbonyl chloride Chemical compound ClC(=O)C1=CC=CC=C1C(Cl)=O FYXKZNLBZKRYSS-UHFFFAOYSA-N 0.000 description 3
- FDQSRULYDNDXQB-UHFFFAOYSA-N benzene-1,3-dicarbonyl chloride Chemical compound ClC(=O)C1=CC=CC(C(Cl)=O)=C1 FDQSRULYDNDXQB-UHFFFAOYSA-N 0.000 description 3
- 238000004132 cross linking Methods 0.000 description 3
- 229920001223 polyethylene glycol Polymers 0.000 description 3
- 229920002451 polyvinyl alcohol Polymers 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 229920005989 resin Polymers 0.000 description 3
- 239000011347 resin Substances 0.000 description 3
- LXEJRKJRKIFVNY-UHFFFAOYSA-N terephthaloyl chloride Chemical compound ClC(=O)C1=CC=C(C(Cl)=O)C=C1 LXEJRKJRKIFVNY-UHFFFAOYSA-N 0.000 description 3
- KMZHZAAOEWVPSE-UHFFFAOYSA-N 2,3-dihydroxypropyl acetate Chemical compound CC(=O)OCC(O)CO KMZHZAAOEWVPSE-UHFFFAOYSA-N 0.000 description 2
- ICSNLGPSRYBMBD-UHFFFAOYSA-N 2-aminopyridine Chemical compound NC1=CC=CC=N1 ICSNLGPSRYBMBD-UHFFFAOYSA-N 0.000 description 2
- WRMNZCZEMHIOCP-UHFFFAOYSA-N 2-phenylethanol Chemical compound OCCC1=CC=CC=C1 WRMNZCZEMHIOCP-UHFFFAOYSA-N 0.000 description 2
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 2
- 238000012695 Interfacial polymerization Methods 0.000 description 2
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 2
- 239000003929 acidic solution Substances 0.000 description 2
- 230000002378 acidificating effect Effects 0.000 description 2
- 150000001263 acyl chlorides Chemical class 0.000 description 2
- 239000004760 aramid Substances 0.000 description 2
- 229920003235 aromatic polyamide Polymers 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000007598 dipping method Methods 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- 239000003651 drinking water Substances 0.000 description 2
- 235000020188 drinking water Nutrition 0.000 description 2
- 230000036541 health Effects 0.000 description 2
- 238000007654 immersion Methods 0.000 description 2
- 239000007791 liquid phase Substances 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 230000008520 organization Effects 0.000 description 2
- YVOFTMXWTWHRBH-UHFFFAOYSA-N pentanedioyl dichloride Chemical compound ClC(=O)CCCC(Cl)=O YVOFTMXWTWHRBH-UHFFFAOYSA-N 0.000 description 2
- CMDGQTVYVAKDNA-UHFFFAOYSA-N propane-1,2,3-triol;hydrate Chemical compound O.OCC(O)CO CMDGQTVYVAKDNA-UHFFFAOYSA-N 0.000 description 2
- 238000007873 sieving Methods 0.000 description 2
- 239000011780 sodium chloride Substances 0.000 description 2
- BXGYBSJAZFGIPX-UHFFFAOYSA-N 2-pyridin-2-ylethanol Chemical compound OCCC1=CC=CC=N1 BXGYBSJAZFGIPX-UHFFFAOYSA-N 0.000 description 1
- GJOWSEBTWQNKPC-UHFFFAOYSA-N 3-methyloxiran-2-ol Chemical compound CC1OC1O GJOWSEBTWQNKPC-UHFFFAOYSA-N 0.000 description 1
- NUKYPUAOHBNCPY-UHFFFAOYSA-N 4-aminopyridine Chemical compound NC1=CC=NC=C1 NUKYPUAOHBNCPY-UHFFFAOYSA-N 0.000 description 1
- FBPFZTCFMRRESA-KVTDHHQDSA-N D-Mannitol Chemical compound OC[C@@H](O)[C@@H](O)[C@H](O)[C@H](O)CO FBPFZTCFMRRESA-KVTDHHQDSA-N 0.000 description 1
- CTENFNNZBMHDDG-UHFFFAOYSA-N Dopamine hydrochloride Chemical compound Cl.NCCC1=CC=C(O)C(O)=C1 CTENFNNZBMHDDG-UHFFFAOYSA-N 0.000 description 1
- 229930195725 Mannitol Natural products 0.000 description 1
- CERQOIWHTDAKMF-UHFFFAOYSA-M Methacrylate Chemical compound CC(=C)C([O-])=O CERQOIWHTDAKMF-UHFFFAOYSA-M 0.000 description 1
- 206010028813 Nausea Diseases 0.000 description 1
- 239000002033 PVDF binder Substances 0.000 description 1
- 229920002873 Polyethylenimine Polymers 0.000 description 1
- 208000001647 Renal Insufficiency Diseases 0.000 description 1
- 239000007983 Tris buffer Substances 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 125000003277 amino group Chemical group 0.000 description 1
- 239000008346 aqueous phase Substances 0.000 description 1
- 239000003125 aqueous solvent Substances 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000001112 coagulating effect Effects 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 208000002173 dizziness Diseases 0.000 description 1
- 229960001149 dopamine hydrochloride Drugs 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 229960004979 fampridine Drugs 0.000 description 1
- 239000013505 freshwater Substances 0.000 description 1
- 125000000524 functional group Chemical group 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 description 1
- 229910000041 hydrogen chloride Inorganic materials 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 201000006370 kidney failure Diseases 0.000 description 1
- 239000002346 layers by function Substances 0.000 description 1
- 239000000594 mannitol Substances 0.000 description 1
- 235000010355 mannitol Nutrition 0.000 description 1
- 230000008693 nausea Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 229920013655 poly(bisphenol-A sulfone) Polymers 0.000 description 1
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000007790 scraping Methods 0.000 description 1
- 238000002791 soaking Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 230000001502 supplementing effect Effects 0.000 description 1
- 238000006557 surface reaction Methods 0.000 description 1
- 208000024891 symptom Diseases 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 235000013619 trace mineral Nutrition 0.000 description 1
- 239000011573 trace mineral Substances 0.000 description 1
- LENZDBCJOHFCAS-UHFFFAOYSA-N tris Chemical compound OCC(N)(CO)CO LENZDBCJOHFCAS-UHFFFAOYSA-N 0.000 description 1
- 238000000108 ultra-filtration Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/02—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor characterised by their properties
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/12—Composite membranes; Ultra-thin membranes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
- B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0002—Organic membrane manufacture
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/40—Polymers of unsaturated acids or derivatives thereof, e.g. salts, amides, imides, nitriles, anhydrides, esters
- B01D71/42—Polymers of nitriles, e.g. polyacrylonitrile
- B01D71/421—Polyacrylonitrile
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/56—Polyamides, e.g. polyester-amides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/66—Polymers having sulfur in the main chain, with or without nitrogen, oxygen or carbon only
- B01D71/68—Polysulfones; Polyethersulfones
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
- C02F1/441—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by reverse osmosis
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2101/00—Nature of the contaminant
- C02F2101/10—Inorganic compounds
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
- C02F2103/08—Seawater, e.g. for desalination
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A20/00—Water conservation; Efficient water supply; Efficient water use
- Y02A20/124—Water desalination
- Y02A20/131—Reverse-osmosis
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Water Supply & Treatment (AREA)
- Manufacturing & Machinery (AREA)
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Environmental & Geological Engineering (AREA)
- Organic Chemistry (AREA)
- Nanotechnology (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
Abstract
The invention provides a boron-removing reverse osmosis membrane and a preparation method thereof. The boron-free reverse osmosis membrane comprises: the support layer is formed on one surface of the substrate, comprises a polymer and a pore-forming agent, and has a porous structure; a desalination layer comprising polyamide; the nano transition layer is positioned between the supporting layer and the desalting layer and is in contact with the supporting layer and the desalting layer; wherein the nano transition layer comprises cellulose nanocrystals. The boron-removing reverse osmosis membrane has high flux and high desalination rate and higher boron-removing rate. Further, the cellulose nanocrystal transition layer improves the stability and the mechanical property of the reverse osmosis membrane desalting layer.
Description
Technical Field
The invention relates to a boron-removing reverse osmosis membrane and a preparation method thereof, in particular to a laminated loading interface polymerization high-boron-removing sea water desalination membrane and a preparation method thereof, and belongs to the field of water treatment.
Background
With the growth of world population and the rapid development of industry, water resource shortage has become a bottleneck restricting the development of socioeconomic performance. Sea water desalination is one of the effective ways to solve the crisis of fresh water resources at present, and reverse osmosis membrane method is one of the main technologies for sea water desalination, and is estimated to account for 44% of the total world sea water desalination and continuously grows year by year. Aromatic polyamide composite membranes are the most commonly used reverse osmosis membranes currently available, with good water flux and desalination rates, and a wider operating temperature and pH range. However, one of the major factors limiting the application of aromatic polyamide reverse osmosis membranes is their relatively low removal rate of uncharged small molecules, such as boric acid.
Boron is a trace element in seawater, mainly exists in the form of uncharged boric acid molecules in seawater, and has the average concentration of 4-7 mg/L, and the highest concentration can reach 9.6mg/L. Boron content exceeding a certain limit is toxic and harmful, and according to the report of World Health Organization (WHO), when the boron content in water exceeds 2.4mg/L, plants are poisoned, and excessive boron also causes symptoms such as dizziness, nausea, renal failure and the like. WHO recommends that the boron content in drinking water should be below 0.5mg/L. Therefore, boron removal is an important indicator in the seawater desalination process.
Boric acid in seawater exists mostly (about 95%) in the form of molecules, so that the electrostatic repulsion mechanism of reverse osmosis membrane to remove salt ions becomes ineffective, uncharged boric acid cannot be removed as effectively as desalination, and boron is removed mainly by pore size sieving and steric hindrance mechanism. The size of the uncharged boric acid molecules is 0.275nm, the Stokes radius is 0.155nm, and the polyamide desalination layer of the reverse osmosis membrane mainly has two hole type structures of network holes with the aperture of 0.1-0.3 nm and aggregation holes with the aperture of 0.4-0.6 nm.
The size of boric acid molecules is close to the pore diameter of the network pores and smaller than the pore diameter of the aggregation pores, so that boric acid can permeate the aggregation pores in the polyamide desalination layer and even enter part of the network pores in the reverse osmosis seawater desalination process, so that the removal rate of the reverse osmosis membrane to boron is lower than 90 percent (about 60-80 percent), the single reverse osmosis process cannot remove boron to the recommended value (< 0.5 mg/L) of World Health Organization (WHO) to the boron content of drinking water, and further reduction of the boron concentration can be realized only by adding various pretreatment and post-treatment processes or multistage reverse osmosis processes, and the energy consumption and the cost are greatly increased. Therefore, the material and the preparation process of the reverse osmosis membrane are required to be improved, and further, the performance is optimized by regulating and controlling the functional layer structure, and the seawater desalination reverse osmosis membrane product with high boron removal rate is developed, so that the boron removal rate is greatly improved while the flux and the high desalination rate of the reverse osmosis membrane are maintained.
Reference 1 discloses a co-hybrid boron-removing affinity membrane and a preparation method thereof, comprising the following steps: (1) grinding ZXC700 boron-removing special resin into powder and sieving; (2) Uniformly mixing the A substance, the ZXC700 boron-removing special resin powder, polyvinylpyrrolidone and an organic solvent, stirring, standing at room temperature, vacuum defoaming until no bubble exists, and preparing the co-mixed boron-removing affinity membrane by a phase inversion precipitation method; the substance A is polysulfone, bisphenol A polysulfone, polyethersulfone or polyvinylidene fluoride. The co-mixed boron-removing affinity membrane has high boron-removing capacity, the boron-removing rate increases along with the increase of the content of the used boron-removing special resin powder ZXC700, but the boron-removing affinity membrane belongs to the field of ultrafiltration membranes, has higher boron-removing rate, has no removing effect on inorganic salts such as sodium chloride, has single effect, cannot achieve the desalination effect of the seawater desalination reverse osmosis membrane on seawater, and cannot be directly used for seawater desalination.
Reference 2 discloses a rapid and efficient boron-removing hollow fiber composite membrane and a preparation method thereof. The hollow fiber composite membrane comprises a polymer porous membrane, wherein the surface of the polymer porous membrane is a hyperbranched polyhydroxy structure polymer molecular brush; the polyhydroxy structure polymer molecular brush takes 1-4 parts of dopamine hydrochloride, 1-4 parts of polyethyleneimine, 2-8 parts of epoxypropanol and 100 parts of Tris buffer solution with the concentration of 10mM as raw materials according to parts by weight. The hollow fiber composite membrane prepared by the method has higher boron removal rate, but the regularity of the hollow fiber membrane cannot be ensured in the membrane preparation process, the hollow fiber membrane is easy to intertwine and break, the membrane component is difficult to prepare, and industrial production cannot be realized.
Citation document
Citation 1: CN103752188A
Citation 2: CN106422809A
Disclosure of Invention
Problems to be solved by the invention
In view of the technical problems existing in the prior art, for example: the invention provides a seawater desalination reverse osmosis membrane with low boron removal performance and the like. The boron-removing reverse osmosis membrane has high flux and high desalination rate and higher boron-removing rate.
Furthermore, the invention also provides a preparation method of the boron-removing reverse osmosis membrane, which is simple and feasible, raw materials are easy to obtain, and mass production can be realized.
Solution for solving the problem
The invention first provides a boron-free reverse osmosis membrane comprising:
the support layer is formed on one surface of the substrate, comprises a polymer and a pore-forming agent, and has a porous structure;
a desalination layer comprising polyamide; and
the nanometer transition layer is positioned between the supporting layer and the desalting layer and is contacted with the supporting layer and the desalting layer; wherein the nano transition layer comprises cellulose nanocrystals.
The boron-removed reverse osmosis membrane provided by the invention, wherein the nano transition layer is formed on the surface of the supporting layer through a covalent bond;
The desalting layer is overlapped on one surface of the nano transition layer opposite to the supporting layer through a covalent bond.
The boron-removing reverse osmosis membrane comprises polyacrylonitrile or a combination of polyacrylonitrile and one or more than two selected from polysulfone, polyethersulfone, polyvinyl chloride and polyetheretherketone; and/or
The pore-forming agent comprises a high molecular pore-forming agent or a small molecular pore-forming agent; preferably, the high molecular pore-forming agent comprises one or more than two of polyethylene glycol, polyvinylpyrrolidone or polyvinyl alcohol; the small molecule pore-forming agent comprises one or more of lithium chloride, calcium chloride or water.
The boron-removed reverse osmosis membrane provided by the invention is characterized in that the support layer is obtained by carrying out hydrolytic modification on the surface of the support layer by using a modifier;
the nano transition layer is obtained by performing functionalization treatment on the surface of the nano transition layer.
The boron-removed reverse osmosis membrane according to the present invention, wherein the cellulose nanocrystals have a diameter of 5 to 15nm, preferably 5 to 10nm; the length of the cellulose nanocrystals is 50 to 300nm, preferably 50 to 100nm.
The invention also provides a preparation method of the boron-removing reverse osmosis membrane, which comprises the step of compositely forming the support layer, the nano transition layer and the desalination layer.
The preparation method comprises the following steps:
dissolving a polymer and a pore-forming agent in a first solvent to obtain a supporting layer solution, and then forming a film on one surface of a substrate by the supporting layer solution to obtain a supporting layer;
dissolving cellulose nanocrystals in a first solvent to obtain a nano transition layer solution, and forming a nano transition layer film on the surface of the supporting layer by using the nano transition layer solution to obtain an intermediate product;
performing functionalization treatment on the position of the intermediate product with the nano transition layer film to obtain a nano transition layer;
and forming a desalting layer on the surface of the nano transition layer opposite to the supporting layer to obtain the boron-removed reverse osmosis membrane.
The preparation method according to the present invention further comprises a step of subjecting the surface of the support layer to hydrolysis modification treatment with a modifier, preferably the modifier comprises an alkaline agent.
The preparation method according to the present invention, wherein the functionalization treatment is performed using a functionalization solution including a first functionalization solution and the second functionalization solution; wherein,,
the first functionalizing solution comprises a crosslinking agent; the second functionalizing solution comprises an amine monomer.
The preparation method according to the present invention, wherein the desalting layer is formed using an oil phase monomer solution and the amine monomer.
ADVANTAGEOUS EFFECTS OF INVENTION
The boron-removing reverse osmosis membrane has high flux and high desalination rate and higher boron-removing rate.
Further, the cellulose nanocrystal transition layer of the invention improves the stability and mechanical properties of the reverse osmosis membrane desalination layer.
Furthermore, the preparation method of the boron-removing reverse osmosis membrane is simple and feasible, raw materials are easy to obtain, and mass production can be realized.
Detailed Description
The following describes the present invention in detail. The following description of the technical features is based on the representative embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples. It should be noted that:
in the present specification, the numerical range indicated by the term "numerical value a to numerical value B" means a range including the end point numerical value A, B.
In the present specification, unless specifically stated otherwise, "a plurality" of "a plurality of" etc. means a numerical value of 2 or more.
In this specification, the terms "substantially", "substantially" or "substantially" mean that the error is less than 5%, or less than 3% or less than 1% compared to the relevant perfect or theoretical standard.
In the present specification, "%" means mass% unless otherwise specified.
In the present specification, the meaning of "can" includes both the meaning of performing a certain process and the meaning of not performing a certain process.
In this specification, "optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not.
Reference throughout this specification to "some specific/preferred embodiments," "other specific/preferred embodiments," "an embodiment," and so forth, means that a particular element (e.g., feature, structure, property, and/or characteristic) described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it is to be understood that the elements may be combined in any suitable manner in the various embodiments.
< first aspect >
A first aspect of the present invention provides a boronized reverse osmosis membrane comprising:
the support layer is formed on one surface of the substrate, comprises a polymer and a pore-forming agent, and has a porous structure;
The desalting layer is a polyamide desalting layer; and
the nanometer transition layer is positioned between the supporting layer and the desalting layer and is contacted with the supporting layer and the desalting layer; wherein the nano transition layer comprises cellulose nanocrystals.
Further, considering the ease of operation in preparation, the nano transition layer is formed on the surface of the support layer by covalent bonds; the desalting layer is overlapped on the surface of the nano transition layer opposite to the supporting layer through a covalent bond.
In some specific embodiments, the debrominated reverse osmosis membranes of the invention comprise:
the support layer is formed on one surface of the substrate, comprises a polymer and a pore-forming agent, and has a porous structure;
the nano transition layer is formed on the surface of the supporting layer through a covalent bond and comprises cellulose nanocrystals;
and the desalting layer is overlapped on one surface of the nano transition layer opposite to the supporting layer through a covalent bond, and the desalting layer is a polyamide desalting layer.
According to the invention, a nano transition layer is introduced between the support layer and the desalination layer through covalent bonds, so that the stability and the mechanical property of the conventional reverse osmosis membrane are improved. Meanwhile, the cellulose nanocrystals and the derivatives thereof have strong boron capturing capability after high functionalization, and the boron removing performance of the laminated loading interface polymerization reverse osmosis membrane is further improved.
Support layer
The supporting layer is formed on one surface of the substrate, comprises a polymer and a pore-forming agent, and has a porous structure. The present invention further enables the formation of nano-transition layers and desalination layers by using polymers to provide active groups to the support layer.
In some specific embodiments, the polymer comprises polyacrylonitrile, or a combination of polyacrylonitrile and one or more selected from polysulfone, polyethersulfone, polyvinylchloride, polyetheretherketone. The pore former comprises a high molecular pore former or a small molecular pore former. The pore-forming agent is used, so that the support layer has a proper pore structure, and the flux of the boron-removed reverse osmosis membrane is improved.
Specifically, the present invention is not particularly limited to the high molecular pore-forming agent or the small molecular pore-forming agent, and may be some high molecular pore-forming agents or small molecular pore-forming agents commonly used in the art, specifically, the high molecular pore-forming agent includes one or a combination of two or more of polyethylene glycol (PEG), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), and the like. The small molecule pore-forming agent comprises one or more of lithium chloride, calcium chloride or water. However, in view of the pore structure requirements of the present invention, it is preferred to use a polymeric pore former, such as polyvinylpyrrolidone (PVP).
In some specific embodiments, the support layer is obtained by hydrolytically modifying its surface with a modifying agent in order to provide the support layer with a large number of reactive groups on its surface. Namely, the support layer is a support layer obtained by subjecting the surface thereof to hydrolytic modification using a modifier.
The modifier is not particularly limited, and may be any modifier commonly used in the art, and an alkaline agent is preferably used as the modifier. Specifically, the alkaline agent may be one or both of sodium hydroxide, potassium hydroxide, and the like, and is preferably sodium hydroxide.
Nano transition layer
The nano transition layer is positioned between the supporting layer and the desalting layer and is contacted with the supporting layer and the desalting layer; wherein the nano transition layer comprises cellulose nanocrystals.
In the invention, the cellulose nanocrystals are connected with the supporting layer and the desalting layer through covalent bonds by introducing the nano transition layer between the supporting layer and the desalting layer, so that the stability and the mechanical property of the boron-removing reverse osmosis membrane are improved.
In some specific embodiments, the nano-transition layer of the present invention is formed on the surface of the support layer by covalent bonds; the nano transition layer can be formed on the surface of the supporting layer by means of dipping, coating, spraying or the like.
In some specific embodiments, the nano transition layer is a nano transition layer obtained by performing functionalization treatment on the surface of the nano transition layer. The surface of the nano transition layer obtained by surface functionalization treatment is provided with a plurality of functional groups, such as amino groups and the like, so that high-density reaction sites can be provided for interfacial polymerization, the influences of base film defects and hydrolysis of oil phase acyl chloride are eliminated, the formation of an ultra-thin polyamide desalting layer with high crosslinking degree and no aggregation hole is promoted, and the boron-removed reverse osmosis membrane has high flux and high desalting rate and simultaneously has higher boron removal rate.
Preferably, the cellulose nanocrystals of the present invention are rod-shaped, in particular, the cellulose nanocrystals have a diameter of 5nm to 15nm, preferably 5nm to 10nm; the length of the cellulose nanocrystals is 50nm to 300nm, preferably 50nm to 100nm.
Desalting layer
The desalting layer of the invention is a polyamide desalting layer. The polyamide desalting layer is an ultrathin polyamide desalting layer with high crosslinking degree and no aggregation hole, so that the boron-removed reverse osmosis membrane has the characteristics of high flux and high desalination rate.
In some specific embodiments, the desalter layer is derived from an oil phase monomer and an amine monomer. Specifically, the oil phase monomer comprises one or more than two of terephthaloyl chloride, isophthaloyl chloride, phthaloyl chloride, cyclohexanetricaoyl chloride, trimesoyl chloride and glutaryl chloride. The amine monomer may be one or a combination of more than two of m-phenylenediamine, o-phenylenediamine, p-phenylenediamine and the like.
< second aspect >
The second aspect of the invention provides a preparation method of the boron-removing reverse osmosis membrane, which comprises the step of compositely forming a support layer, a nano transition layer and a desalination layer. The preparation method of the boron-removed reverse osmosis membrane is simple and feasible, raw materials are easy to obtain, and the method is suitable for mass production.
In some specific embodiments, the preparation method of the present invention comprises the steps of:
dissolving a polymer and a pore-forming agent in a first solvent to obtain a supporting layer solution, and then forming a film on one surface of a substrate by the supporting layer solution to obtain a supporting layer;
dissolving cellulose nanocrystals in a first solvent to obtain a nano transition layer solution, and forming a nano transition layer film on the surface of the supporting layer by using the nano transition layer solution to obtain an intermediate product;
performing functionalization treatment on the position of the intermediate product with the nano transition layer film to obtain a nano transition layer;
and forming a desalting layer on the surface of the nano transition layer opposite to the supporting layer to obtain the boron-removed reverse osmosis membrane.
Preparation of support layer
In the present invention, a supporting layer is obtained by dissolving a polymer and a pore-forming agent in a first solvent to obtain a supporting layer solution, and then forming a film of the supporting layer solution on one surface of a substrate.
In particular, for the polymer and the pore former, it may be the polymer and pore former of the first aspect; for the first solvent of the present invention, it may include one or a combination of two or more of N, N-Dimethylformamide (DMF), N-Dimethylacetamide (DMAC), N-methylpyrrolidone (NMP), dimethylsulfoxide (DMSO).
In some embodiments, for better film formation of the support layer solution by solid-liquid phase conversion, the polymer is present in an amount of 15wt% to 20wt%, preferably 16wt% to 19wt%, based on the total mass of the support layer solution; the content of the pore-forming agent is 0.1-5 wt%, preferably 0.4-4 wt%; the content of the first solvent is 75wt% to 84.9wt%, preferably 77wt% to 83.6wt%. Specifically, the content of the polymer is 15.5wt%, 16.5wt%, 17wt%, 17.5wt%, 18wt%, 18.5wt%, etc.; the content of the pore-forming agent is 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, etc.; the content of the first solvent is 74wt%, 76wt%, 78wt%, 80wt%, 82wt%, 83wt%, 84 wt%, etc. Preferably, in preparing the support layer solution, the treatment may be performed at a suitably elevated temperature in order to accelerate the dissolution of the solute. In particular, the temperature may be between 40 ℃ and 100 ℃, preferably between 50 ℃ and 90 ℃, for example: 45 ℃, 55 ℃, 65 ℃, 75 ℃, 85 ℃, 95 ℃, etc.
Specifically, the supporting layer solution can be prepared by the following method: and (3) adding the pore-forming agent into the first solvent in a stirring state in proportion for mixing and dispersing, maintaining the stirring state and heating to 40-100 ℃, adding the polymer into the mixture, and supplementing the first solvent to 100wt% for the rest part to obtain the supporting layer solution.
Further, the present invention provides a polymer primary film obtained by forming the support layer solution into a film. In order to obtain a polymer primary film with excellent performance, the film formation may be to form a film of the prepared supporting layer solution by a solid-liquid phase conversion method. Specifically, the support layer solution prepared in advance is uniformly coated (e.g. knife coated) on a substrate, the substrate coated with the support layer solution is slowly immersed in a coagulating bath, and a polymer primary film is obtained by scraping through a gel curing process, wherein the substrate is preferably a non-woven fabric, and polypropylene non-woven fabric is preferably used in view of alkali resistance of the non-woven fabric.
Preferably, the main component of the coagulation bath of the present invention is water, and in order to ensure the diffusion rate of the solvent between two phases, the temperature of the coagulation bath needs to be controlled to be 10 ℃ to 25 ℃, for example: 12 ℃, 15 ℃, 18 ℃, 20 ℃, 22 ℃ and the like; the treatment time in the coagulation dissolution is 200s to 400s, for example: 220s, 250s, 280s, 300s, 320s, 350s, 380s, etc.
In some specific embodiments, in order to make the surface structure and the internal structure of the polymer primary film more suitable for preparing the nano transition layer and the desalting layer, the method further comprises the step of defoaming treatment before the supporting layer solution is formed into a film, and in the invention, all defoaming processes are carried out in a vacuum defoaming box, and the vacuum pump pressure is between-100 kPa and-60 MPa, for example: -90kPa, -80kPa, -70kPa, etc.
In some specific embodiments, the method of making further comprises the step of hydrolytically modifying the surface of the support layer with a modifying agent, preferably the modifying agent comprises an alkaline agent. Specifically, the alkaline agent may be one or a combination of two of sodium hydroxide, potassium hydroxide, and the like.
Preferably, the modifier is an alkaline aqueous solution, and in the alkaline aqueous solution, the concentration of the alkaline agent is 3wt% to 8wt%, for example: 4wt%, 5wt%, 6wt%, 7wt%, etc. The modification treatment is preferably performed at a temperature of 40 to 80 ℃, for example: 45 ℃, 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃ and the like; the modification time is 5min to 30min, for example: 10min, 15min, 20min, 25min, etc.
In some preferred embodiments, the modifying step comprises subjecting the polymeric primary film to an aqueous alkaline solution for surface hydrolytic modification.
In addition, the invention can also carry out post-treatment on the obtained modified polymer primary membrane, wherein the post-treatment comprises the step of washing the polymer primary membrane to be neutral by deionized water, so as to obtain the support layer.
Preparation of nano transition layer
In the present invention, the nano transition layer solution is obtained by dissolving cellulose nanocrystals in a first solvent. Specifically, the present invention is not particularly limited, and the first solvent used in the support layer may be one. Specifically, it may include one or two combinations of N, N-Dimethylformamide (DMF), N-Dimethylacetamide (DMAC), N-methylpyrrolidone (NMP), and Dimethylsulfoxide (DMSO).
In some specific embodiments, in the present invention, when preparing the nano-transition layer solution, the mass ratio of cellulose nanocrystals to the first solvent may be 1:80 to 120, for example: 1:85, 1:90, 1:95, 1:100, 1:105, 1:110, 1:115, etc. Further, in order to enable the nano-transition layer to be better combined with the support layer, a catalyst can be added during preparation of the nano-transition layer solution, so that cellulose nanocrystals in the nano-transition layer and active groups on the surface of the support layer can be better subjected to chemical reaction to generate covalent bonds.
Specifically, the catalyst is one or more of N, N-Dicyclohexylcarbodiimide (DCC), N-diisopropylcarbodiimide, 1-cyclohexyl-2-morpholinohexylcarbodiimide p-toluenesulfonate, 4-Dimethylaminopyridine (DMAP), 2-aminopyridine, 2-hydroxyethyl pyridine and 3, 4-aminopyridine. Preferably, in preparing the nano-transition layer solution, the catalysts used are N, N-Dicyclohexylcarbodiimide (DCC) and 4-Dimethylaminopyridine (DMAP). The amount of the catalyst to be added is not particularly limited, and may be an amount commonly used in the art.
Further, the cellulose nanocrystals and the catalyst may be added to the first solvent for ultrasonic dispersion for a period of 5min to 20min, thereby obtaining a uniformly mixed CNC-DMF solution. In addition, when preparing the nano transition layer solution, it may be performed at a certain temperature, and preferably, the temperature may be 25 to 80 ℃, for example: 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃ and the like.
Further, the nano transition layer solution forms a nano transition layer film on the surface of the supporting layer to obtain an intermediate product.
In some specific embodiments, the support layer may be immersed in a nano-transition layer solution such that the nano-transition layer film is formed on the surface of the support layer. Preferably, the support layer may be freed from the residual solution on its surface before it is immersed in the transition layer, for example by drying or wiping. Specifically, the support layer is immersed in the transition layer solution for 10 to 30 minutes after removing the surface residual solution of the support layer, for example: 15min, 20min, 25min, etc.; the residual solution was then removed again to give the intermediate product.
In some specific embodiments, the intermediate product is functionalized at the location with the nano transition layer film to obtain a nano transition layer. Specifically, the functionalization treatment is performed using a functionalization solution including a first functionalization solution and a second functionalization solution; wherein the first functionalizing solution comprises a crosslinking agent; the second functionalizing solution comprises an amine monomer.
The intermediate product may be immersed in the first functionalizing solution for a period of time ranging from 10 minutes to 60 minutes, for example: 20min, 30min, 40min, 50min, etc., then the surface residual solution is removed and immersed in the second functionalization solution for 10min to 60min, for example: 20min, 30min, 40min, 50min, etc., and then taking out and washing with deionized water to obtain the nano transition layer.
The nano transition layer provides high-density reaction sites for interfacial polymerization after functionalization treatment, eliminates the influence of base film defects and oil phase acyl chloride hydrolysis, promotes the generation of an ultra-thin polyamide desalting layer with high crosslinking degree and no aggregation hole, and the prepared reverse osmosis membrane has high flux and high desalting rate and higher boron removal rate. On the other hand, the high functionalization endows the cellulose nanocrystals and the derivatives thereof with strong boron capturing capability, and prevents the penetration of boron so as to further improve the boron removing performance of the laminated loading interface polymerization composite reverse osmosis membrane. The method has the characteristic of low boron removal performance of the reverse osmosis membrane in the prior art.
For the first functionalized solution, the crosslinking agent may be specifically dissolved in the second solvent to obtain the first functionalized solution. Specifically, the crosslinking agent may be one or a combination of two or more of Methyl Acrylate (MA), methacrylate, methyl methacrylate, butyl acrylate, ethyl methacrylate, and the like. The second solvent may be one or a combination of two or more of Tetrahydrofuran (THF), acetone, toluene, anisole, methylene chloride, and the like.
In some specific embodiments, in the present invention, the mass ratio of the crosslinking agent to the second solvent may be 1:1 to 10, preferably 1:2 to 8, for example: 1:3, 1:4, 1:5, 1:6, 1:7, 1:9, etc.
Further, to enable better binding of the nano-transition layer to the amine monomer, a catalyst may be added during the preparation of the first functionalized solution to better chemically react the cellulose nanocrystals in the nano-transition layer with the amine monomer to create covalent bonds. Specifically, the catalyst may be one or a combination of more than two of alpha-bromoisobutyryl bromide (BIB), 2-dibromomethyl-1, 3-dibromopropane, dibromomethylbenzene, alpha-dibromobenzyl, alpha-dibromoethyl acetate, alpha-dibromoparaxylene and the like. The amount of the catalyst to be added is not particularly limited, and may be an amount commonly used in the art.
Specifically, the preparation method of the first functionalized solution may be to sequentially add the crosslinking agent and the catalyst into the second solvent and mix them uniformly to obtain the first functionalized solution for standby. In addition, the preparation of the first functionalized solution may be carried out at a temperature, preferably 50 to 80 ℃, for example: 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃ and the like.
For the second functionalized solution, the amine monomer may be specifically dissolved in a second solvent to obtain the second functionalized solution. Specifically, the amine monomer may be one or a combination of two or more of m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, etc., and the second solvent may be one or a combination of two or more of Tetrahydrofuran (THF), acetone, toluene, anisole, dichloromethane, etc.
In some specific embodiments, in the present invention, the mass ratio of amine monomer to second solvent in preparing the second functionalized solution may be from 1:5 to 20, preferably from 1:7 to 15, for example: 1:6, 1:8, 1:9, 1:10, 1:11, 1:12, 1:14, 1:16, 1:18, 1:19, etc.
Further, to enable better bonding of the transition layer to the amine monomer, a catalyst may be added in preparing the second functionalized solution to better chemically react the cellulose nanocrystals in the transition layer with the amine monomer to create covalent bonds. Specifically, the catalyst may be one or a combination of two or more of tetra-n-butyl ammonium bromide (TBAB), triethylbenzyl ammonium chloride, dodecyltrimethyl ammonium bromide, cetyltrimethylammonium bromide, dodecyltrimethyl ammonium chloride, and the like. The amount of the catalyst to be added is not particularly limited, and may be an amount commonly used in the art.
Specifically, the preparation method of the second functionalized solution may be to sequentially add the amine monomer and the catalyst into the second solvent and mix them uniformly to obtain the second functionalized solution for standby. In addition, in preparing the second functionalizing solution, it may be carried out at a temperature, preferably 50 to 80 ℃, such as: 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃ and the like.
Preparation of the desalting layer
The desalting layer of the invention can be directly formed on the surface of the nano transition layer.
In some specific embodiments, the salt-free layer may be formed using the amine monomer in an oil phase monomer solution and a second functionalized solution. Specifically, the obtained support layer with the nano transition layer formed thereon may be immersed in an oil phase monomer solution and a humectant solution to obtain a boron-free reverse osmosis membrane. The order of impregnation in the oil phase monomer solution and the humectant solution is not particularly limited, and the present invention may be impregnated in the humectant solution or the oil phase monomer solution. Preferably, the aqueous phase may be immersed in the oil phase monomer solution before being immersed in the humectant solution.
Specifically, the membrane may be immersed in the oil phase monomer solution first, and the immersion time is not too long. In general, the time for immersion in the oil phase monomer solution may be 30s to 60s, for example: 35s, 40s, 45s, 50s, 55s, etc.; then the oil phase dipping product and the residual solution are cleaned by using an acid solution, and the cleaning time is 3 min-6 min; finally, soaking the mixture in the humectant solution for 3-6 min, such as 4min, 5min, etc. Taking out and drying to obtain the boron-removing reverse osmosis membrane, wherein the drying temperature can be 50-90 ℃, preferably 70-80 ℃, for example: 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 85 ℃, etc.
Further, as for the oil phase monomer solution, it is possible to dissolve the oil phase active monomer in the third solvent, thereby obtaining an oil phase monomer solution. Specifically, the oil phase active monomer is one or more than two of terephthaloyl chloride, isophthaloyl chloride, phthaloyl chloride, cyclohexanetricaoyl chloride, trimesoyl chloride and glutaryl chloride. The third solvent may be a common organic solvent, for example: one or more of n-hexane, cyclohexane, n-heptane, toluene, chloroform, isopar G and the like.
In some specific embodiments, the concentration of the oil phase active monomer in the oil phase monomer solution is 0.05wt% to 3.0wt% and the addition amount of the third solvent is 97wt% to 99.95wt% based on the total mass of the oil phase monomer solution. Specifically, the oil phase monomer may be added in an amount of 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 2.8wt%, etc.; the third solvent may be added in an amount of 97.2wt%, 97.5wt%, 98wt%, 98.5wt%, 99wt%, 99.5wt%, etc.
In addition, for the acidic solution used in the washing process, it may be hydrochloric acid substance dissolved in water, wherein the concentration of the acidic substance may be 0.5wt% to 3.0wt% based on the total mass of the acidic solution. Preferably, the acidic substance is hydrogen chloride.
Further, for the humectant solution, the humectant may be dissolved in a fourth solvent, thereby obtaining the humectant solution. Specifically, the humectant is one or more than two of glycerol, phenethyl alcohol, glycerol monoacetate, isopropanol and mannitol. The fourth solvent may be a conventional aqueous solvent, for example: deionized water, and the like.
In some specific embodiments, the humectant concentration in the humectant solution is from 5wt% to 15.0wt%, based on the total mass of the humectant solution, for example: 7wt%, 9wt%, 11wt%, 13wt%, 14wt%, etc.; the addition amount of the fourth solvent is 85-95 wt%; for example: 86wt%, 87wt%, 89wt%, 91wt%, 93wt%, etc.
Examples
Embodiments of the present invention will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.
Example 1
(1) Preparation of cellulose nanocrystal solution: mixing Cellulose Nanocrystals (CNC) and N, N-Dimethylformamide (DMF) according to a mass ratio of 1:100, adding catalysts N, N-Dicyclohexylcarbodiimide (DCC) and 4-Dimethylaminopyridine (DMAP) to carry out ultrasonic dispersion for 10min to obtain a CNC-DMF solution which is uniformly mixed, and heating to 70 ℃ for standby;
(2) Preparing a nano transition layer functionalization solution: acrylic acid methyl ester as cross-linking agent ( MA) and Tetrahydrofuran (THF) are mixed according to the mass ratio of 4:1, and a catalyst alpha-bromoisobutyryl bromide (BIB) is added, stirred and mixed uniformly to obtain a functionalized solution (1), and the functionalized solution is heated to 70 ℃ for standby. Mixing m-phenylenediamine and Tetrahydrofuran (THF) according to a mass ratio of 1:10, adding a catalyst tetra-n-butyl ammonium bromide (TBAB), stirring and mixing uniformly to obtain a functionalized solution (2), and heating to 70 ℃ for later use;
(3) Preparation of the supporting layer: 0.1wt% of polyvinylpyrrolidone is added into N, N-Dimethylformamide (DMF) in a stirring state for mixing and dispersing, the stirring state is maintained and the temperature is raised to 70 ℃, 15.0wt% of polyacrylonitrile is added into the mixture, and the rest is supplemented to 100wt% by the N, N-Dimethylformamide (DMF), so as to obtain a polymer homogeneous solution. Then filtering after vacuum defoamation treatment under-80 kPa, cooling to room temperature, uniformly coating on a non-woven fabric substrate by adopting a scraper system, and immersing the non-woven fabric substrate in a deionized water coagulation bath at 15 ℃ for 300 seconds to obtain a Polyacrylonitrile (PAN) primary membrane. Immersing a Polyacrylonitrile (PAN) primary membrane into a 5.0wt% sodium hydroxide solution at 40 ℃ for surface hydrolysis modification, taking out after 30min, and washing to neutrality by deionized water to obtain an HPAN support layer;
(4) The support layer carries a cellulose nanocrystal transition layer: removing the residual solution on the surface of the HPAN support layer obtained in the step (3), immersing the HPAN support layer in the solution at 70 ℃ prepared in the step (1) for 20min, and taking out the residual solution to obtain the HAPN-CNC film;
(5) Functionalization of the cellulose nanocrystal transition layer: immersing the HPAN-CNC film obtained in the step (4) into the solution (1) at 70 ℃ prepared in the step (2) for 30min, taking out to remove the surface residual solution, immersing the HPAN-CNC film into the solution (2) at 70 ℃ prepared in the step (2) for 30min, and taking out to wash the HPAN-CNC-a film loaded with amine monomers by deionized water;
(6) Preparation of a desalting layer: immersing the HPAN-CNC-a membrane prepared in the step (5) into an oil phase solution which takes normal hexane as a solvent and contains 0.05wt% of terephthaloyl chloride for 30s, taking out to remove the normal hexane solution remained on the surface, washing for 5min by using 2.0wt% of dilute hydrochloric acid, immersing in 8.0wt% of glycerol aqueous solution for 5min, taking out, and drying in a drying oven at 50 ℃ to obtain the laminated loading interface polymerization boron-removing reverse osmosis membrane LIP-SWRO-1.
In example 1, the cellulose nanocrystals were 5nm in diameter and 50nm in length; the non-woven fabric base material is polypropylene (PP).
Example 2
(1) Preparation of cellulose nanocrystal solution: mixing Cellulose Nanocrystals (CNC) and N, N-Dimethylformamide (DMF) according to a mass ratio of 1:100, adding catalysts N, N-Dicyclohexylcarbodiimide (DCC) and 4-Dimethylaminopyridine (DMAP) to carry out ultrasonic dispersion for 10min to obtain a CNC-DMF solution which is uniformly mixed, and heating to 70 ℃ for standby;
(2) Preparing a nano transition layer functionalization solution: mixing a crosslinking agent Methyl Acrylate (MA) and Tetrahydrofuran (THF) according to a mass ratio of 4:1, adding a catalyst alpha-bromoisobutyryl bromide (BIB), stirring and mixing uniformly to obtain a functionalized solution (1), and heating to 70 ℃ for standby. Mixing m-phenylenediamine and Tetrahydrofuran (THF) according to a mass ratio of 1:10, adding a catalyst tetra-n-butyl ammonium bromide (TBAB), stirring and mixing uniformly to obtain a functionalized solution (2), and heating to 70 ℃ for later use;
(3) Preparation of the supporting layer: 1.0wt% of polyvinylpyrrolidone is added into N, N-Dimethylformamide (DMF) in a stirring state for mixing and dispersing, the stirring state is maintained and the temperature is raised to 70 ℃, 16.0wt% of polyacrylonitrile is added into the mixture, and the rest is supplemented to 100wt% by the N, N-Dimethylformamide (DMF), so as to obtain a polymer homogeneous solution. Then filtering after vacuum defoamation treatment under-80 kPa, cooling to room temperature, uniformly coating on a non-woven fabric substrate by adopting a scraper system, and immersing the non-woven fabric substrate in a deionized water coagulation bath at 18 ℃ for 300 seconds to obtain a Polyacrylonitrile (PAN) primary membrane. Immersing a Polyacrylonitrile (PAN) primary membrane into a 5.0wt% sodium hydroxide solution at 50 ℃ for surface hydrolysis modification, taking out after 30min, and washing to be neutral by deionized water to obtain an HPAN support layer;
(4) The support layer carries a cellulose nanocrystal transition layer: removing the residual solution on the surface of the HPAN support layer obtained in the step (3), immersing the HPAN support layer in the solution at 70 ℃ prepared in the step (1) for 15min, and taking out the residual solution to obtain the HAPN-CNC film;
(5) Functionalization of the cellulose nanocrystal transition layer: immersing the HPAN-CNC film obtained in the step (4) into the 70 ℃ solution (1) prepared in the step (2) for 40min, taking out to remove the surface residual solution, immersing the HPAN-CNC film into the 70 ℃ solution (2) prepared in the step (2) for 30min, taking out, and washing the HPAN-CNC film with deionized water to obtain an amine monomer-loaded HPAN-CNC-a film;
(6) Preparation of a desalting layer: immersing the HPAN-CNC-a membrane prepared in the step (5) into an oil phase solution which takes cyclohexane as a solvent and contains 0.5wt% of isophthaloyl dichloride for 40s, taking out to remove the cyclohexane solution remained on the surface, washing for 5min by using 2.0wt% of dilute hydrochloric acid, immersing in 8.0wt% of glycerol aqueous solution for 5min, taking out, and drying in a 60 ℃ oven to obtain the laminated loading interface polymerization high-boron removal seawater desalination reverse osmosis membrane LIP-SWRO-2.
In example 2, the cellulose nanocrystals were 10nm in diameter and 50nm in length; the non-woven fabric base material is polypropylene (PP).
Example 3
(1) Preparation of cellulose nanocrystal solution: mixing Cellulose Nanocrystals (CNC) and N, N-Dimethylformamide (DMF) according to a mass ratio of 1:100, adding catalysts N, N-Dicyclohexylcarbodiimide (DCC) and 4-Dimethylaminopyridine (DMAP) to carry out ultrasonic dispersion for 10min to obtain a CNC-DMF solution which is uniformly mixed, and heating to 70 ℃ for standby;
(2) Preparing a nano transition layer functionalization solution: mixing a crosslinking agent Methyl Acrylate (MA) and Tetrahydrofuran (THF) according to a mass ratio of 4:1, adding a catalyst alpha-bromoisobutyryl bromide (BIB), stirring and mixing uniformly to obtain a functionalized solution (1), and heating to 70 ℃ for standby. Mixing m-phenylenediamine and Tetrahydrofuran (THF) according to a mass ratio of 1:10, adding a catalyst tetra-n-butyl ammonium bromide (TBAB), stirring and mixing uniformly to obtain a functionalized solution (2), and heating to 70 ℃ for later use;
(3) Preparation of the supporting layer: 1.5wt% of polyvinylpyrrolidone was added to N, N-Dimethylformamide (DMF) in a stirred state to conduct mixed dispersion, the temperature was raised to 70℃while maintaining the stirred state, 18.0wt% of polyacrylonitrile was added thereto, and the remainder was supplemented to 100wt% with N, N-Dimethylformamide (DMF), to obtain a homogeneous polymer solution. Then vacuum defoamation treatment is carried out under-80 kPa, filtration is carried out, cooling is carried out to room temperature, a scraper system is adopted to uniformly coat the non-woven fabric base material, and the non-woven fabric base material is immersed into deionized water coagulation bath at 20 ℃ for treatment for 300 seconds, thus obtaining the Polyacrylonitrile (PAN) primary membrane. Immersing a Polyacrylonitrile (PAN) primary membrane into a 5.0wt% sodium hydroxide solution at 60 ℃ for surface hydrolysis modification, taking out after 30min, and washing to be neutral by deionized water to obtain an HPAN support layer;
(4) The support layer carries a cellulose nanocrystal transition layer: removing the residual solution on the surface of the HPAN support layer obtained in the step (3), immersing the HPAN support layer in the solution at 70 ℃ prepared in the step (1) for 25min, and taking out the residual solution to obtain the HAPN-CNC film;
(5) Functionalization of the cellulose nanocrystal transition layer: immersing the HPAN-CNC film obtained in the step (4) into the 70 ℃ solution (1) prepared in the step (2) for 35min, taking out to remove the surface residual solution, immersing the HPAN-CNC film into the 70 ℃ solution (2) prepared in the step (2) for 20min, taking out, and washing the HPAN-CNC film with deionized water to obtain an amine monomer-loaded HPAN-CNC-a film;
(6) Preparation of a desalting layer: immersing the HPAN-CNC-a membrane prepared in the step (5) into an oil phase solution which takes n-heptane as a solvent and contains 1.0wt% of phthaloyl chloride for 45s, taking out to remove the n-heptane solution remained on the surface, washing for 5min by using 2.0wt% of dilute hydrochloric acid, immersing in 8.0wt% of glycerol water solution for 5min, taking out, and drying in a drying oven at 70 ℃ to obtain the laminated loading interface polymerization high-boron removal seawater desalination reverse osmosis membrane LIP-SWRO-3.
In example 3, the cellulose nanocrystals were 10nm in diameter and 100nm in length; the non-woven fabric base material is polypropylene (PP).
Example 4
(1) Preparation of cellulose nanocrystal solution: mixing Cellulose Nanocrystals (CNC) and N, N-Dimethylformamide (DMF) according to a mass ratio of 1:100, adding catalysts N, N-Dicyclohexylcarbodiimide (DCC) and 4-Dimethylaminopyridine (DMAP) to carry out ultrasonic dispersion for 10min to obtain a CNC-DMF solution which is uniformly mixed, and heating to 70 ℃ for standby;
(2) Preparing a nano transition layer functionalization solution: mixing a crosslinking agent MA and Tetrahydrofuran (THF) according to a mass ratio of 4:1, adding a catalyst alpha-bromoisobutyryl bromide (BIB), stirring and mixing uniformly to obtain a functionalized solution (1), and heating to 70 ℃ for standby. Mixing m-phenylenediamine and THF according to a mass ratio of 1:10, adding a catalyst tetra-n-butyl ammonium bromide (TBAB), stirring and mixing uniformly to obtain a functionalized solution (2), and heating to 70 ℃ for later use;
(3) Preparation of the supporting layer: 3.0wt% of polyvinylpyrrolidone is added into N, N-Dimethylformamide (DMF) in a stirring state for mixing and dispersing, the stirring state is maintained and the temperature is raised to 70 ℃, 19.0wt% of polyacrylonitrile is added into the mixture, and the rest is supplemented to 100wt% by the N, N-Dimethylformamide (DMF), so as to obtain a polymer homogeneous solution. Then vacuum defoamation treatment is carried out under-80 kPa, filtration is carried out, cooling is carried out to room temperature, a scraper system is adopted to uniformly coat the non-woven fabric base material, and the non-woven fabric base material is immersed into deionized water coagulation bath at 20 ℃ for treatment for 300 seconds, thus obtaining the Polyacrylonitrile (PAN) primary membrane. Immersing a Polyacrylonitrile (PAN) primary membrane into a 5.0wt% sodium hydroxide solution at 70 ℃ for surface hydrolysis modification, taking out after 30min, and washing to neutrality by deionized water to obtain an HPAN support layer;
(4) The support layer carries a cellulose nanocrystal transition layer: removing the residual solution on the surface of the HPAN support layer obtained in the step (3), immersing the HPAN support layer in the solution at 70 ℃ prepared in the step (1) for 15min, and taking out the residual solution to obtain the HAPN-CNC film;
(5) Functionalization of the cellulose nanocrystal transition layer: immersing the HPAN-CNC film obtained in the step (4) into the 70 ℃ solution (1) prepared in the step (2) for 45min, taking out to remove the surface residual solution, immersing the HPAN-CNC film into the 70 ℃ solution (2) prepared in the step (2) for 25min, taking out, and washing the HPAN-CNC film with deionized water to obtain an amine monomer-loaded HPAN-CNC-a film;
(6) Preparation of a desalting layer: immersing the HPAN-CNC-a membrane prepared in the step (5) into an oil phase solution which takes toluene as a solvent and contains 2.0wt% of cyclohexanetricamide chloride for 50s, taking out to remove toluene solution remained on the surface, washing for 5min by using 2.0wt% of dilute hydrochloric acid, immersing in 8.0wt% of glycerol water solution for 5min, taking out, and drying in an oven at 80 ℃ to obtain the laminated loading interface polymerization high-boron removal seawater desalination reverse osmosis membrane LIP-SWRO-4.
In example 4, the cellulose nanocrystals were 10nm in diameter and 200nm in length; the non-woven fabric base material is polypropylene (PP).
Example 5
(1) Preparation of cellulose nanocrystal solution: mixing Cellulose Nanocrystals (CNC) and N, N-Dimethylformamide (DMF) according to a mass ratio of 1:100, adding catalysts N, N-Dicyclohexylcarbodiimide (DCC) and 4-Dimethylaminopyridine (DMAP) to carry out ultrasonic dispersion for 10min to obtain a CNC-DMF solution which is uniformly mixed, and heating to 70 ℃ for standby;
(2) Preparing a nano transition layer functionalization solution: mixing a crosslinking agent MA and Tetrahydrofuran (THF) according to a mass ratio of 4:1, adding a catalyst alpha-bromoisobutyryl bromide (BIB), stirring and mixing uniformly to obtain a functionalized solution (1), and heating to 70 ℃ for standby. Mixing m-phenylenediamine and Tetrahydrofuran (THF) according to a mass ratio of 1:10, adding a catalyst tetra-n-butyl ammonium bromide (TBAB), stirring and mixing uniformly to obtain a functionalized solution (2), and heating to 70 ℃ for later use;
(3) Preparation of the supporting layer: 5.0wt% of polyvinylpyrrolidone is added into N, N-Dimethylformamide (DMF) in a stirring state for mixing and dispersing, the stirring state is maintained and the temperature is raised to 70 ℃, 20.0wt% of polyacrylonitrile is added into the mixture, and the rest is supplemented to 100wt% by the N, N-Dimethylformamide (DMF), so as to obtain a polymer homogeneous solution. Then filtering after vacuum defoamation treatment under-80 kPa, cooling to room temperature, uniformly coating on a non-woven fabric substrate by adopting a scraper system, and immersing the non-woven fabric substrate in a deionized water coagulation bath at 18 ℃ for 300 seconds to obtain a Polyacrylonitrile (PAN) primary membrane. Immersing a Polyacrylonitrile (PAN) primary membrane into a 5.0wt% sodium hydroxide solution at 80 ℃ for surface hydrolysis modification, taking out after 30min, and washing to be neutral by deionized water to obtain an HPAN support layer;
(4) The support layer carries a cellulose nanocrystal transition layer: removing the residual solution on the surface of the HPAN support layer obtained in the step (3), immersing the HPAN support layer in the solution at 70 ℃ prepared in the step (1) for 20min, and taking out the residual solution to obtain the HAPN-CNC film;
(5) Functionalization of the cellulose nanocrystal transition layer: immersing the HPAN-CNC film obtained in the step (4) into the 70 ℃ solution (1) prepared in the step (2) for 25min, taking out to remove the surface residual solution, immersing the HPAN-CNC film into the 70 ℃ solution (2) prepared in the step (2) for 40min, taking out, and washing the HPAN-CNC film with deionized water to obtain an amine monomer-loaded HPAN-CNC-a film;
(6) Preparation of a desalting layer: immersing the HPAN-CNC-a membrane prepared in the step (5) into an oil phase solution which takes isopar G as a solvent and contains 3.0wt% of trimesoyl chloride for 60s, taking out to remove the isopar G solution remained on the surface, washing for 5min by using 2.0wt% of dilute hydrochloric acid, immersing in 8.0wt% of glycerol aqueous solution for 5min, taking out, putting into a 90 ℃ oven for drying, and obtaining the laminated loading interface polymerization high-boron removal seawater desalination reverse osmosis membrane LIP-SWRO-5.
In example 5, the cellulose nanocrystals were 15nm in diameter and 300nm in length; the non-woven fabric base material is polypropylene (PP).
Comparative example 1
(1) Preparation of the supporting layer: 5.0wt% of polyvinylpyrrolidone is added into N, N-Dimethylformamide (DMF) in a stirring state for mixing and dispersing, the stirring state is maintained and the temperature is raised to 70 ℃, 18.0wt% of polyacrylonitrile is added into the mixture, and the rest is supplemented to 100wt% by the N, N-Dimethylformamide (DMF), so as to obtain a polymer homogeneous solution. Then filtering after vacuum defoamation treatment under-80 kPa, cooling to room temperature, uniformly coating on a non-woven fabric substrate by adopting a scraper system, and immersing the non-woven fabric substrate in a deionized water coagulation bath at 15 ℃ for 300 seconds to obtain the porous supporting layer.
(2) Preparation of a desalting layer: immersing the porous support layer prepared in the step (1) into 3.0wt% m-phenylenediamine aqueous solution for 60s, and taking out the aqueous solution for removing surface residues; then immersing in an oil phase solution which takes normal hexane as a solvent and contains 3.0wt% of trimesic acid chloride for 40s, taking out to remove the normal hexane solution remained on the surface, washing for 5min by using 2.0wt% of dilute hydrochloric acid, immersing in 8.0wt% of glycerol aqueous solution for 5min, taking out and putting into a 90 ℃ oven for drying, thus obtaining the SWRO reverse osmosis membrane.
In comparative example 1, the nonwoven fabric substrate was made of polypropylene (PP).
Performance testing
The boron-removed reverse osmosis membranes LIP-SWRO-1, LIP-SWRO-2, LIP-SWRO-3, LIP-SWRO-4 and LIP-SWRO-5 prepared in examples 1 to 5, and the SWRO reverse osmosis membranes of comparative example 1 were placed in a high pressure membrane test station for testing. The reverse osmosis membrane was tested for water flux, desalination rate and boron removal rate after 30 minutes of operation under the test conditions of an operation pressure of 800psi, raw water of 32000.+ -. 1000ppm sodium chloride and 5.+ -. 0.5ppm boric acid aqueous solution, a solution temperature of 25 ℃ and a pH value of 6.5 to 7.5, and the results are shown in Table 1.
TABLE 1
As can be seen from table 1, the boron-removed reverse osmosis membranes of examples 1 to 5 were excellent in water flux, desalination rate and boron removal rate. Accordingly, the boron-removed reverse osmosis membranes of examples 1 to 5 of the present application have higher boron removal rates while having comparable flux and high desalination rates, as compared to the reverse osmosis membrane of comparative example 1.
It should be noted that, although the technical solution of the present invention is described in specific embodiments, those skilled in the art should understand that the present invention should not be limited thereto.
The foregoing description of embodiments of the invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the various embodiments described. The terminology used herein was chosen in order to best explain the principles of the embodiments, the practical application, or the technical improvements in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.
Claims (7)
1. A debrominated reverse osmosis membrane comprising:
the support layer is formed on one surface of the substrate, comprises a polymer and a pore-forming agent, and has a porous structure;
a desalination layer comprising polyamide;
the nano transition layer is positioned between the supporting layer and the desalting layer and is in contact with the supporting layer and the desalting layer; wherein the nano transition layer comprises cellulose nanocrystals, the diameter of the cellulose nanocrystals is 5-10 nm, and the length of the cellulose nanocrystals is 50-100 nm;
The nano transition layer is formed on the surface of the supporting layer through a covalent bond; the desalting layer is overlapped on one surface of the nano transition layer opposite to the supporting layer through a covalent bond;
the supporting layer is obtained by carrying out hydrolytic modification on the surface of the supporting layer by using a modifier;
the nano transition layer is obtained by performing functionalization treatment on the surface of the nano transition layer; the functionalization treatment is carried out by using a functionalization solution, wherein the functionalization solution comprises a first functionalization solution and a second functionalization solution;
the first functional solution is prepared by dissolving a cross-linking agent in a second solvent, and adding a catalyst, wherein the cross-linking agent is one or a combination of more than two of methyl acrylate, methyl methacrylate, butyl acrylate and ethyl methacrylate; the second solvent is one or more than two of tetrahydrofuran, acetone, toluene, anisole and methylene dichloride; the catalyst added into the first functionalization solution is one or more than two of alpha-bromoisobutyryl bromide, 2-dibromomethyl-1, 3-dibromopropane, dibromomethylbenzene, alpha-dibromobenzyl, alpha-dibromoethyl acetate and alpha, alpha-dibromoparaxylene;
The second functionalization solution is prepared by dissolving an amine monomer in a second solvent and adding a catalyst; the amine monomer is one or the combination of more than two of m-phenylenediamine, o-phenylenediamine and p-phenylenediamine; the second solvent is one or more than two of tetrahydrofuran, acetone, toluene, anisole and methylene dichloride; the catalyst added into the second functionalization solution is one or more than two of tetra-n-butyl ammonium bromide, triethyl benzyl ammonium chloride, dodecyl trimethyl ammonium bromide, hexadecyl trimethyl ammonium bromide and dodecyl trimethyl ammonium chloride.
2. The boronizing reverse osmosis membrane of claim 1, wherein the polymer comprises polyacrylonitrile, or a combination of polyacrylonitrile and one or more selected from polysulfone, polyethersulfone, polyvinylchloride, polyetheretherketone; the pore-forming agent comprises a high molecular pore-forming agent or a small molecular pore-forming agent; the small molecule pore-forming agent comprises one or more of lithium chloride, calcium chloride or water.
3. The method for preparing the debrominated reverse osmosis membrane according to any one of claims 1 to 2, comprising the step of compositely shaping a support layer, a nano transition layer and a desalination layer.
4. A method of preparation according to claim 3, comprising the specific steps of:
dissolving a polymer and a pore-forming agent in a first solvent to obtain a supporting layer solution, and then forming a film on one surface of a substrate by the supporting layer solution to obtain a supporting layer;
dissolving cellulose nanocrystals in a first solvent to obtain a nano transition layer solution, and forming a nano transition layer film on the surface of the supporting layer by using the nano transition layer solution to obtain an intermediate product;
performing functionalization treatment on the position of the intermediate product with the nano transition layer film to obtain a nano transition layer;
and forming a desalting layer on the surface of the nano transition layer opposite to the supporting layer to obtain the boron-removed reverse osmosis membrane.
5. The method according to claim 4, further comprising the step of subjecting the surface of the support layer to hydrolysis modification treatment with a modifier.
6. The method according to claim 4, wherein the functionalization treatment is performed using a functionalization solution including a first functionalization solution and a second functionalization solution; wherein the first functionalizing solution comprises a crosslinking agent; the second functionalizing solution comprises an amine monomer.
7. The method of claim 6, wherein the desalting layer is formed using an oil phase monomer solution and the amine monomer.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011503729.2A CN114642972B (en) | 2020-12-18 | 2020-12-18 | Deboron reverse osmosis membrane and preparation method thereof |
| PCT/CN2021/135768 WO2022127635A1 (en) | 2020-12-18 | 2021-12-06 | Boron-removal reverse osmosis membrane and preparation method therefor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011503729.2A CN114642972B (en) | 2020-12-18 | 2020-12-18 | Deboron reverse osmosis membrane and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114642972A CN114642972A (en) | 2022-06-21 |
| CN114642972B true CN114642972B (en) | 2023-06-13 |
Family
ID=81991664
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011503729.2A Active CN114642972B (en) | 2020-12-18 | 2020-12-18 | Deboron reverse osmosis membrane and preparation method thereof |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN114642972B (en) |
| WO (1) | WO2022127635A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115430296A (en) * | 2022-09-20 | 2022-12-06 | 中国科学院过程工程研究所 | Composite nanofiltration membrane with catalytic intermediate layer and preparation method and application thereof |
| CN115501765B (en) * | 2022-10-27 | 2024-06-28 | 安徽大学 | Hollow fiber membrane, method for constructing hydrophilic network thereof, and use thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106999870A (en) * | 2016-06-30 | 2017-08-01 | 中国石油大学(华东) | The molecule of polysulfonamide nanofiltration or reverse osmosis composite membrane process for assembly preparing layer by layer |
| CN110141974A (en) * | 2019-05-17 | 2019-08-20 | 李文国 | A kind of nano-cellulose-composite nanometer filtering film (CNF-NF) and preparation method thereof |
| CN110975645A (en) * | 2019-12-09 | 2020-04-10 | 南方科技大学 | Preparation method of composite film and composite film |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130105383A1 (en) * | 2011-10-27 | 2013-05-02 | Nanyang Technological University | Nanofiltration-type thin film composite forward osmosis membrane and a method of synthesizing the same |
| US10322379B2 (en) * | 2014-07-21 | 2019-06-18 | Ohio State Innovation Foundation | Composite membranes for separation of gases |
| CN106739363A (en) * | 2016-05-05 | 2017-05-31 | 林小锋 | A kind of thin-film composite membrane of multi-layer compound structure and preparation method thereof |
| CN111054214A (en) * | 2018-10-16 | 2020-04-24 | 天津天元新材料科技有限公司 | Preparation method of composite reverse osmosis membrane |
-
2020
- 2020-12-18 CN CN202011503729.2A patent/CN114642972B/en active Active
-
2021
- 2021-12-06 WO PCT/CN2021/135768 patent/WO2022127635A1/en active Application Filing
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106999870A (en) * | 2016-06-30 | 2017-08-01 | 中国石油大学(华东) | The molecule of polysulfonamide nanofiltration or reverse osmosis composite membrane process for assembly preparing layer by layer |
| CN110141974A (en) * | 2019-05-17 | 2019-08-20 | 李文国 | A kind of nano-cellulose-composite nanometer filtering film (CNF-NF) and preparation method thereof |
| CN110975645A (en) * | 2019-12-09 | 2020-04-10 | 南方科技大学 | Preparation method of composite film and composite film |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114642972A (en) | 2022-06-21 |
| WO2022127635A1 (en) | 2022-06-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114642972B (en) | Deboron reverse osmosis membrane and preparation method thereof | |
| Wang et al. | Novel RO membranes fabricated by grafting sulfonamide group: Improving water permeability, fouling resistance and chlorine resistant performance | |
| CN104619403B (en) | Composite semipermeable membrane | |
| KR101985351B1 (en) | Composite semipermeable membrane, composite semipermeable membrane element, and method for manufacturing composite semipermeable membrane | |
| JP6052172B2 (en) | Manufacturing method of composite semipermeable membrane | |
| CN114682102B (en) | Reverse osmosis membrane and preparation method thereof | |
| CN110947307B (en) | Preparation method of composite desalination layer nanofiltration membrane | |
| CN106582318A (en) | Organic solvent-resistant nanofiltration membrane modified by graphene oxide, and preparation method and application thereof | |
| CN109351190A (en) | It is a kind of to be crosslinked the compound solvent resistant nanofiltration membrane of fluorine-containing polyamide, preparation method and applications | |
| CN113117539B (en) | Reverse osmosis membrane based on modified polyolefin substrate and preparation method thereof | |
| JPWO2014133133A1 (en) | Composite semipermeable membrane | |
| Mi et al. | Positively charged nanofiltration membrane prepared by polydopamine deposition followed by crosslinking for high efficiency cation separation | |
| Fang et al. | Evaluating the antifouling properties of poly (ether sulfone)/sulfonated poly (ether sulfone) blend membranes in a full-size membrane module | |
| CN114053886A (en) | Polyamide composite reverse osmosis membrane and preparation method thereof | |
| CN115888415A (en) | Preparation method of nanofiltration membrane and nanofiltration membrane prepared by same | |
| JP2001286741A (en) | Reverse osmosis composite membrane and manufacturing method therefor | |
| CN112619443A (en) | Composite reverse osmosis membrane and preparation method thereof | |
| CN112221356B (en) | Chlorine-resistant reverse osmosis membrane and preparation method and application thereof | |
| KR20150078245A (en) | Hollow fiber type nanofiltration membrane having high ions removal capacity, and manufacturing method thereof | |
| CN107970779B (en) | Reverse osmosis membrane and preparation method and application thereof | |
| CN115888428A (en) | High-selectivity nanofiltration composite membrane and preparation method thereof | |
| CN115245757B (en) | Composite nanofiltration membrane and preparation method and application thereof | |
| JP2000176263A (en) | Composite semipermeable membrane and its production | |
| CN108025265A (en) | Composite semipermeable membrane | |
| JP2017148771A (en) | Composite semipermeable membrane |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |