CN112999889A - Method for preparing PMIA mixed matrix membrane with photocatalytic performance by self-adhesion and application - Google Patents
Method for preparing PMIA mixed matrix membrane with photocatalytic performance by self-adhesion and application Download PDFInfo
- Publication number
- CN112999889A CN112999889A CN202110208117.9A CN202110208117A CN112999889A CN 112999889 A CN112999889 A CN 112999889A CN 202110208117 A CN202110208117 A CN 202110208117A CN 112999889 A CN112999889 A CN 112999889A
- Authority
- CN
- China
- Prior art keywords
- pmia
- membrane
- self
- mixed matrix
- adhesion
- 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.)
- Pending
Links
- 229920000889 poly(m-phenylene isophthalamide) Polymers 0.000 title claims abstract description 97
- 238000000034 method Methods 0.000 title claims abstract description 52
- 230000001699 photocatalysis Effects 0.000 title claims abstract description 31
- 239000004941 mixed matrix membrane Substances 0.000 title claims description 30
- 239000012528 membrane Substances 0.000 claims abstract description 116
- 238000005266 casting Methods 0.000 claims abstract description 38
- 229910021649 silver-doped titanium dioxide Inorganic materials 0.000 claims abstract description 22
- 239000011941 photocatalyst Substances 0.000 claims abstract description 20
- 238000002360 preparation method Methods 0.000 claims abstract description 19
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims abstract description 18
- 239000002351 wastewater Substances 0.000 claims abstract description 9
- 239000002105 nanoparticle Substances 0.000 claims abstract description 6
- 239000000243 solution Substances 0.000 claims description 51
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical group [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 claims description 30
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 25
- 238000005191 phase separation Methods 0.000 claims description 24
- 230000008569 process Effects 0.000 claims description 15
- 239000002904 solvent Substances 0.000 claims description 15
- 238000003756 stirring Methods 0.000 claims description 15
- 239000011248 coating agent Substances 0.000 claims description 12
- 238000000576 coating method Methods 0.000 claims description 12
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 claims description 11
- 239000007864 aqueous solution Substances 0.000 claims description 8
- 239000000463 material Substances 0.000 claims description 8
- 239000006184 cosolvent Substances 0.000 claims description 7
- 230000003197 catalytic effect Effects 0.000 claims description 6
- 230000015556 catabolic process Effects 0.000 claims description 4
- 238000006731 degradation reaction Methods 0.000 claims description 4
- 239000002086 nanomaterial Substances 0.000 claims description 4
- 239000000758 substrate Substances 0.000 claims description 4
- 239000002114 nanocomposite Substances 0.000 claims description 3
- JOPOVCBBYLSVDA-UHFFFAOYSA-N chromium(6+) Chemical compound [Cr+6] JOPOVCBBYLSVDA-UHFFFAOYSA-N 0.000 abstract description 14
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 abstract description 4
- 229910052804 chromium Inorganic materials 0.000 abstract description 4
- 239000011651 chromium Substances 0.000 abstract description 4
- 238000004043 dyeing Methods 0.000 abstract description 4
- 238000007146 photocatalysis Methods 0.000 abstract description 4
- 238000007639 printing Methods 0.000 abstract description 4
- 238000006555 catalytic reaction Methods 0.000 abstract description 3
- WZCQRUWWHSTZEM-UHFFFAOYSA-N 1,3-phenylenediamine Chemical compound NC1=CC=CC(N)=C1 WZCQRUWWHSTZEM-UHFFFAOYSA-N 0.000 abstract description 2
- 238000013033 photocatalytic degradation reaction Methods 0.000 abstract description 2
- -1 polyisophthaloyl Polymers 0.000 abstract description 2
- 239000000126 substance Substances 0.000 abstract description 2
- 239000003054 catalyst Substances 0.000 abstract 1
- 238000011084 recovery Methods 0.000 abstract 1
- 238000000108 ultra-filtration Methods 0.000 description 19
- 239000008367 deionised water Substances 0.000 description 14
- 229910021641 deionized water Inorganic materials 0.000 description 14
- 239000011521 glass Substances 0.000 description 14
- 239000000853 adhesive Substances 0.000 description 9
- 238000010531 catalytic reduction reaction Methods 0.000 description 9
- 239000000499 gel Substances 0.000 description 9
- 230000004048 modification Effects 0.000 description 9
- 238000012986 modification Methods 0.000 description 9
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 8
- 229910052760 oxygen Inorganic materials 0.000 description 8
- 239000001301 oxygen Substances 0.000 description 8
- OUUQCZGPVNCOIJ-UHFFFAOYSA-M Superoxide Chemical compound [O-][O] OUUQCZGPVNCOIJ-UHFFFAOYSA-M 0.000 description 7
- 238000007790 scraping Methods 0.000 description 7
- 238000005516 engineering process Methods 0.000 description 6
- 239000003344 environmental pollutant Substances 0.000 description 6
- 231100000719 pollutant Toxicity 0.000 description 6
- 238000000926 separation method Methods 0.000 description 6
- 238000003860 storage Methods 0.000 description 6
- 239000002131 composite material Substances 0.000 description 5
- 230000004907 flux Effects 0.000 description 5
- 229910001385 heavy metal Inorganic materials 0.000 description 5
- 238000006722 reduction reaction Methods 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 150000002500 ions Chemical class 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 230000009467 reduction Effects 0.000 description 4
- 238000009825 accumulation Methods 0.000 description 3
- 238000004140 cleaning Methods 0.000 description 3
- 238000001914 filtration Methods 0.000 description 3
- 230000035699 permeability Effects 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 239000000356 contaminant Substances 0.000 description 2
- 238000011109 contamination Methods 0.000 description 2
- 239000003651 drinking water Substances 0.000 description 2
- 235000020188 drinking water Nutrition 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 229910021645 metal ion Inorganic materials 0.000 description 2
- 238000002715 modification method Methods 0.000 description 2
- 238000001728 nano-filtration Methods 0.000 description 2
- 239000002957 persistent organic pollutant Substances 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 230000002035 prolonged effect Effects 0.000 description 2
- 238000005215 recombination Methods 0.000 description 2
- 230000006798 recombination Effects 0.000 description 2
- 238000002791 soaking Methods 0.000 description 2
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 2
- 238000004065 wastewater treatment Methods 0.000 description 2
- RBTBFTRPCNLSDE-UHFFFAOYSA-N 3,7-bis(dimethylamino)phenothiazin-5-ium Chemical compound C1=CC(N(C)C)=CC2=[S+]C3=CC(N(C)C)=CC=C3N=C21 RBTBFTRPCNLSDE-UHFFFAOYSA-N 0.000 description 1
- BTJIUGUIPKRLHP-UHFFFAOYSA-N 4-nitrophenol Chemical compound OC1=CC=C([N+]([O-])=O)C=C1 BTJIUGUIPKRLHP-UHFFFAOYSA-N 0.000 description 1
- 239000002313 adhesive film Substances 0.000 description 1
- 230000003373 anti-fouling effect Effects 0.000 description 1
- 229920006231 aramid fiber Polymers 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000021615 conjugation Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000003574 free electron Substances 0.000 description 1
- 239000000017 hydrogel Substances 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000005374 membrane filtration Methods 0.000 description 1
- 229960000907 methylthioninium chloride Drugs 0.000 description 1
- 231100000252 nontoxic Toxicity 0.000 description 1
- 230000003000 nontoxic effect Effects 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 231100000572 poisoning Toxicity 0.000 description 1
- 230000000607 poisoning effect Effects 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 238000011112 process operation Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000001878 scanning electron micrograph Methods 0.000 description 1
- 238000004626 scanning electron microscopy Methods 0.000 description 1
- 239000010865 sewage Substances 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000004448 titration Methods 0.000 description 1
- 238000003911 water pollution Methods 0.000 description 1
Images
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
- B01D69/14—Dynamic membranes
- B01D69/141—Heterogeneous membranes, e.g. containing dispersed material; Mixed matrix membranes
- B01D69/148—Organic/inorganic mixed matrix 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
- B01D61/14—Ultrafiltration; Microfiltration
- B01D61/145—Ultrafiltration
-
- 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
- B01D67/0079—Manufacture of membranes comprising organic and inorganic components
-
- 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
- B01D67/0081—After-treatment of organic or inorganic membranes
- B01D67/0093—Chemical modification
-
- 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
- B01D69/06—Flat membranes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
- B01J23/54—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
- B01J23/66—Silver or gold
-
- B01J35/39—
-
- 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
- C02F1/30—Treatment of water, waste water, or sewage by irradiation
-
- 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
- C02F1/444—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by ultrafiltration or microfiltration
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/36—Hydrophilic membranes
-
- 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
- C02F2101/20—Heavy metals or heavy metal compounds
- C02F2101/22—Chromium or chromium compounds, e.g. chromates
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2305/00—Use of specific compounds during water treatment
- C02F2305/10—Photocatalysts
Abstract
The invention relates to a method for preparing a polyisophthaloyl metaphenylene diamine film with self-adhesion photocatalysis performance and application thereof, and a preparation method bagComprises the following steps: preparing poly (m-phenylene isophthalamide) (PMIA) to obtain a casting solution, and then dispersing ZnO-Ag-TiO2The solution of (A) is subjected to a gel bath, and the photocatalyst ZnO-Ag-TiO is subjected to a self-adhesion method2Loading the PMIA film on the PMIA film to prepare the PMIA photocatalytic film; the film can be used for improving the capability of reducing harmful substance hexavalent chromium in printing and dyeing wastewater into trivalent chromium by catalysis. Compared with the prior art, the invention uses the photocatalyst ZnO-Ag-TiO2The PMIA membrane is fixed on the surface of the PMIA casting membrane, and the inorganic nano particle modified PMIA membrane is introduced by a self-adhesion method, so that the problems of difficult loss and recovery of the catalyst and the like are reduced, the hydrophilicity is greatly enhanced, and the PMIA membrane has better photocatalytic degradation performance.
Description
Technical Field
The invention belongs to the technical field of membrane separation, and particularly relates to a method for preparing a PMIA mixed matrix membrane with photocatalytic performance by self-adhesion and application of the PMIA mixed matrix membrane.
Background
The membrane separation technology is one of the preferable technologies in the field of water pollution control engineering, and is widely applied to drinking water purification and wastewater treatment and recycling due to low cost, good effluent quality, high intensification degree, simple equipment and convenient operation. However, the membrane pollution phenomenon, especially organic pollution, often causes the attenuation of membrane flux, the increase of operation cost and the shortening of membrane service life, thereby becoming a major obstacle for the wide application of membrane separation technology in drinking water, sewage and wastewater treatment.
Chinese patent CN103881122A discloses a preparation method of a polyvinyl chloride/nano tin dioxide composite membrane with high visible light catalytic activity, the membrane has wide raw material sources and simple preparation method, the obtained composite membrane has excellent photocatalytic activity and stability under visible light, and is extremely easy to separate and recycle from degradation liquid, thus being suitable for industrial application. However, the membrane prepared by the method has insufficient pollution resistance to organic pollutant methylene blue and low interception efficiency. Chinese patent CN107158960A discloses a preparation method of a high-flux and anti-pollution polyisophthaloyl metaphenylene diamine nanofiltration membrane. The method is simple in process operation, and by adopting the method, the contact angle of the prepared nanofiltration membrane is reduced from about 78 degrees to about 45 degrees under the condition of keeping the rejection rate to be increased, so that the hydrophilicity and the pollution resistance of the membrane are greatly improved.
In the preparation method of the membrane disclosed in the above-mentioned chinese patent, the membrane has an anti-pollution capability by its own catalytic performance. But also has disadvantages in that the membrane material is clogged due to the accumulation of contaminants, and the anti-contamination capability is weakened.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide a method for preparing a PMIA mixed matrix membrane with photocatalytic performance by self-adhesion and application thereof.
The purpose of the invention can be realized by the following technical scheme:
the first purpose of the invention is to protect a method for preparing a PMIA mixed matrix membrane with photocatalytic performance by self-adhesion and an application, wherein the method comprises the following steps: hydrothermally synthesized ZnO-Ag-TiO with photocatalytic performance2The water solution of the nano composite material is used as a gel bath for the PMIA membrane to carry out non-solvent induced phase separation, and is self-adhered to the PMIA membrane in the non-solvent induced phase separation process, so that the nano particles are fixed on the surface of the membrane, and the PMIA mixed matrix membrane with the photocatalytic performance is obtained.
Further, the self-pasting process comprises the following steps: the casting solution is immediately immersed in ZnO-Ag-TiO after being blade-coated2The self-adhesion of the photocatalyst is realized in the gel bath of (2).
Further, the preparation method of the casting solution comprises the following steps: and adding the cosolvent and PMIA into N, N-dimethylacetamide, uniformly stirring, standing and defoaming to obtain the membrane casting solution.
Further, in the standing and defoaming process, the standing time is 5-12 h.
Furthermore, the cosolvent content in the casting solution is 4.5g/L, and the PMIA content is 12-20 g/L.
Further, the cosolvent is LiCl;
and in the stirring process of the casting solution, the stirring temperature is 50-100 ℃, and the stirring time is 8-18 h.
Further, ZnO-Ag-TiO in the gel bath2The concentration of the nano material is 0.2-1.8 g/L.
Further, the non-solvent induced phase separation method comprises: coating the casting solution on a substrate, and placing the substrate on ZnO-Ag-TiO2Carrying out phase separation in aqueous solution gel bath, and in the phase separation process, ZnO-Ag-TiO2And sticking the film to the surface of the film by self-adhesion to obtain the PMIA film with photocatalytic performance.
Further, coating the casting solution with a thickness of 100-250 μm;
the temperature of the gel bath was 25 ℃.
The second purpose of the invention is to protect a PMIA mixed matrix membrane with photocatalytic performance, which is prepared by adopting the method.
The third purpose of the invention is to protect the application of the PMIA mixed matrix membrane in catalytic degradation of dye wastewater.
The PMIA membrane with photocatalytic performance is prepared by the self-adhesion method, can be used for catalytic reduction of harmful heavy metal ions and hexavalent chromium in printing and dyeing wastewater, and is particularly used for improving the pollutant resistance of a catalytic membrane reactor device.
ZnO-Ag-TiO prepared by the invention2The photocatalyst modified PMIA ultrafiltration membrane can be used for catalyzing a membrane reactor device to reduce heavy metal ion hexavalent chromium under the irradiation of a visible light lamp, so that the problem of heavy metal pollution of printing and dyeing wastewater is reduced. By using the ZnO-Ag-TiO of the invention2The method for realizing pollution resistance of the PMIA ultrafiltration membrane modified by the photocatalyst under the irradiation of visible light comprises the following steps:
constructing a catalytic membrane reactor device by reacting ZnO-Ag-TiO2Photocatalyst-modified PMFixing IA ultrafiltration membrane on the membrane module, fixing the LED visible light lamp at a position 10cm away from the surface of the membrane, and fixing ZnO-Ag-TiO2The PMIA ultrafiltration membrane modified by the photocatalyst is used for a high-valence wastewater solution flux experiment, after filtration is carried out for 30min in the dark, the visible light lamp is turned on for filtration and catalysis is carried out at the same time, and photocatalytic degradation of harmful high-valence wastewater solution is realized under the irradiation of the LED visible light lamp. The high valence state waste water solution comprises hexavalent chromium solution. The concentration change at the wavelength of 540nm in a certain period of time is detected by an ultraviolet spectrophotometer after titration with DCP solution.
ZnO-Ag-TiO of the invention2The PMIA ultrafiltration membrane modified by the photocatalyst can activate ZnO-Ag-TiO on the surface of the membrane under the irradiation of visible light2The photocatalyst generates active oxygen free radicals with oxidizability, and the active oxygen free radicals can perform reduction reaction with hexavalent chromium to catalyze pollutants into nontoxic trivalent chromium.
The PMIA self-adhesive film of the invention shows excellent reducibility when treated with hexavalent chromium. This is because the inorganic nanomaterial is embedded into the concave surface of the hybrid membrane surface during the phase separation process, which results in a smoother membrane surface that is less prone to contaminant accumulation. On the other hand, as hydrophilicity increases, the "hydrated layer" of the membrane surface effectively prevents the access of foulants, making fouling accumulation in the membrane pores more difficult, exhibiting anti-fouling performance. Meanwhile, free electrons generated under visible light and superoxide radical formed by the combination of dissolved oxygen in water can reduce hexavalent chromium solution with high valence state to trivalent chromium which has little harm to environment and is easy to treat.
The preparation method of the invention is to prepare the prepared ZnO-Ag-TiO2The water solution is inoculated to the PMIA membrane surface in a gel bath mode, and the inorganic nano particle self-adhesion method and the NIPS method are introduced to modify the PMIA membrane, so that the mechanical strength of the composite membrane is improved, the hydrophilicity is greatly improved, and the composite membrane has better reduction capability. Compared with other methods, the self-adhesive method modification enables light to better contact the surface of the film, can better generate superoxide radical, and has the following advantages: the modification and the film formation are carried out synchronously, the process is simple, and complicated post-treatment steps are not needed; energy of photocatalystThe membrane structure is not damaged, and the filtration and the catalysis can be carried out simultaneously.
Compared with the prior art, the invention has the following characteristics:
1) the invention provides ZnO-Ag-TiO2Compared with the traditional PMIA ultrafiltration membrane, the photocatalyst modified PMIA ultrafiltration membrane has higher hydrophilicity and obvious photocatalytic performance; ZnO-Ag-TiO2In the photocatalyst, ZnO and TiO are irradiated by an ultraviolet lamp2Can generate a large amount of excited electrons, and can be combined with dissolved oxygen in solution to generate superoxide radical (. O)2 -) Has catalytic reduction performance, can catalytically reduce harmful metal ions with high valence, and Ag is connected with ZnO and TiO as an intermediate2The recombination rate of excited electrons and electron hole pairs can be delayed, the electrons are in a free state for a longer time, so that more oxygen is combined to form a superoxide radical, the prepared membrane has a self-cleaning function, pollutants cannot be accumulated on the membrane, the service life of the membrane is prolonged, and harmful heavy metal ions can be catalytically reduced while the membrane filters the pollutants;
2) the invention provides ZnO-Ag-TiO2Photocatalyst modified PMIA ultrafiltration membrane and ultraviolet photocatalyst (such as TiO)2) Compared with the modified PMIA film, the energy consumption and the cost are obviously reduced, and the efficiency is higher;
3) the invention prepares ZnO-Ag-TiO2The method for preparing the photocatalyst modified PMIA ultrafiltration membrane is simple and easy to operate, the used equipment is a conventional instrument in the field, the process period is short, the requirement on the process environment is low, the cost is low, and the method can be widely applied to preparation of the photocatalyst modified PMIA membrane;
4) the invention prepares ZnO-Ag-TiO2The method for modifying the PMIA ultrafiltration membrane by the photocatalyst is a self-adhesive modification method, and the photocatalyst ZnO-Ag-TiO in the membrane is modified2Is not easy to dissolve out along with water flow in the using process, avoids poisoning and potential secondary pollution to the water body, and ensures the durability and stability of the membrane structure.
Drawings
FIG. 1 is a scanning electron micrograph of the surface of a PMIA film prepared in example 1;
FIG. 2 is a graph comparing water flux of photocatalyst-modified PMIA membranes (M1-M5) prepared in examples 1-5 with that of PMIA raw membrane M0;
FIG. 3 shows ZnO-Ag-TiO compounds prepared in examples 1 to 52Graph comparing the efficiency of photocatalyst modified PMIA film (M1-M5) and PMIA original film M0 in the process of photocatalytic reduction of hexavalent chromium.
FIG. 4 is a graph comparing the UV absorption of hexavalent chromium by the catalytic reduction of the PMIA film prepared in example 4.
Detailed Description
The invention is described in detail below with reference to the figures and specific embodiments.
As part of the concept of the present solution, PMIA has a hydrogen bonding network structure, which makes it have excellent mechanical properties and good thermal stability (Tg 558K). The pressure resistance and heat resistance of membrane materials are necessary for long-term operation of membrane separation processes, and these excellent properties make PMIA one of the key materials in the field of membrane preparation. More importantly, the PMIA has good hydrophilicity, good permeability and potential of pollution resistance due to the fact that the main chain of the PMIA contains a large number of aramid fiber groups and hydrogen bond networks. In addition, the material is easy to dissolve in a common organic solvent DMAc, so that the PMIA ultrafiltration membrane is prepared by adopting a non-solvent induced phase inversion (NIPS) method in the technical scheme, and the possibility is provided for industrial production. It is known that the application of PMIA membranes in printing and dyeing wastewater can be improved by physical and chemical means, and the modification methods can be mainly divided into two major types, namely membrane surface modification and membrane material modification. The membrane surface modification is mainly to endow the membrane surface with functionality, and the hydrophilic groups are not easy to fall off due to simple operation, so that the membrane surface modification is convenient for large-scale popularization and is a hotspot of research in recent years.
As a part of the technical scheme, the light energy generated by the light energy regenerated by the photocatalysis technology can generate active radical superoxide radical to realize the degradation of organic pollutants in water and the catalytic reduction of high-valence compounds. Therefore, the photocatalysis technology is combined with the membrane modification technology to form the composite photocatalysis separation modified membrane, and the self-cleaning capability, the hydrophilic performance and the interception characteristic of the membrane can be effectively improved.
In this embodiment, the preparation method of the PMIA film with photocatalytic performance by a self-adhesive method includes the following steps:
1) preparing a casting solution: adding auxiliary solvents LiCl and PMIA into N, N-dimethylacetamide (DMAc), stirring for 8-18h at 50-100 ℃, standing and defoaming to obtain the casting solution, blade-coating the casting solution, and immediately immersing the casting solution into ZnO-Ag-TiO2The self-adhesion of the photocatalyst to the surface of the membrane is realized in the gel bath, and the GO-ZnO-Ag nano composite material in the technical scheme can be prepared by referring to the existing literature.
2) Non-solvent induced phase separation method PMIA mixed matrix membrane preparation: and (3) coating the casting film liquid on a glass plate in a scraping thickness of 100-250 mu m, and placing the glass plate in a 15-30 ℃ hydrogel bath for phase separation to obtain the PMIA mixed matrix film.
Wherein the gel bath is ZnO-Ag-TiO2The concentration of the nano material aqueous solution is 0.2-1.8 g/L; the mass of the cosolvent in the casting solution is 4.5g/L, and the mass of PMIA is 12-20 g/L.
The invention adds photocatalyst into the film, and ZnO and TiO are irradiated by ultraviolet light2Can generate a large amount of excited electrons, and can be combined with dissolved oxygen in solution to generate superoxide radical (. O)2 -) Has catalytic reduction performance, can catalytically reduce harmful metal ions with high valence, and Ag is connected with ZnO and TiO as an intermediate2Can delay the recombination rate of excitation electron and electron hole pair on, make electron free state more for a long time to combine more oxygen formation superoxide radical, the membrane of preparation has self-cleaning function, and the pollutant can not be accumulated on the membrane, has prolonged the life of membrane, also can catalytic reduction harmful heavy metal ion when membrane filtration pollutant.
The following are more detailed embodiments, and the technical solutions and the technical effects obtained by the present invention will be further described by the following embodiments.
Example 1:
this example was used to prepare a PMIA mixed matrix membrane, the specific preparation method being as follows:
1) dissolving 4.5g LiCl and 18g PMIA in DMAc, stirring for 8 hours at 50 ℃ until the LiCl and the PMIA are fully dissolved, and standing and defoaming for 6 hours to obtain a casting solution;
2) coating the casting solution on a glass plate in a scraping way, wherein the thickness of the scraped film is 100 mu m;
3) soaking a glass plate with membrane liquid into 0.2g/L of ZnO-Ag-TiO2Self-adhesive phase separation is carried out in aqueous solution;
4) and transferring the membrane after phase separation into deionized water to be soaked so as to remove redundant solvent, and then putting the membrane into clean deionized water for storage to obtain the PMIA self-adhesive membrane marked as an M1 ultrafiltration membrane.
The obtained M1 ultrafiltration membrane was characterized by scanning electron microscopy, and the results are shown in fig. 1. As can be seen from the figure, the membrane cross-section is dense in surface but has large membrane pores.
Example 2:
this example was used to prepare a PMIA mixed matrix membrane, the specific preparation method being as follows:
1) dissolving 4.5g LiCl and 15g PMIA in DMAc, stirring for 10h at 70 ℃ until the LiCl and the PMIA are fully dissolved, and standing and defoaming for 10h to obtain a casting solution;
2) coating the casting solution on a glass plate in a scraping way, wherein the thickness of the scraped film is 150 mu m;
3) soaking the glass plate with the casting solution into 0.5g/L ZnO-Ag-TiO2Self-adhesive phase separation is carried out in aqueous solution;
4) and transferring the membrane after phase separation into deionized water to be soaked so as to remove redundant solvent, and then putting the membrane into clean deionized water for storage to obtain a PMIA mixed matrix membrane which is marked as an M2 ultrafiltration membrane.
Example 3:
this example was used to prepare a PMIA mixed matrix membrane, the specific preparation method being as follows:
1) dissolving 4.5g LiCl and 17g PMIA in DMAc, stirring for 10h at 80 ℃ until the LiCl and the PMIA are fully dissolved, and standing and defoaming for 8h to obtain a casting solution;
2) coating the casting solution on a glass plate in a scraping way, wherein the thickness of the scraped film is 200 mu m;
3) immersing a glass plate with the casting solution into 1g/L of ZnO-Ag-TiO2Self-adhesive phase separation is carried out in aqueous solution;
4) and transferring the membrane after phase separation into deionized water to be soaked so as to remove redundant solvent, and then putting the membrane into clean deionized water for storage to obtain a PMIA mixed matrix membrane which is marked as an M3 ultrafiltration membrane.
Example 4:
this example was used to prepare a PMIA mixed matrix membrane, the specific preparation method being as follows:
1) dissolving 4.5g LiCl and 14g PMIA in DMAc, stirring for 8 hours at 90 ℃ until the LiCl and the PMIA are fully dissolved, and standing and defoaming for 5 hours to obtain a casting solution;
2) coating the casting solution on a glass plate in a scraping way, wherein the thickness of the scraped film is 220 mu m;
3) immersing a glass plate with the casting solution into 1.5g/L ZnO-Ag-TiO2Self-adhesive phase separation is carried out in aqueous solution;
4) and transferring the membrane after phase separation into deionized water to be soaked so as to remove redundant solvent, and then putting the membrane into clean deionized water for storage to obtain a PMIA mixed matrix membrane which is marked as an M4 ultrafiltration membrane.
Comparative graph of ultraviolet absorption of hexavalent chromium by catalytic reduction of the PMIA film prepared in example 4.
Example 5:
this example was used to prepare a PMIA mixed matrix membrane, the specific preparation method being as follows:
1) dissolving 4.5g LiCl and 20g PMIA in DMAc, stirring for 18h at 100 ℃ until the LiCl and the PMIA are fully dissolved, and standing and defoaming for 12h to obtain a casting solution;
2) coating the casting solution on a glass plate in a scraping way, wherein the thickness of the scraped film is 250 mu m;
3) immersing a glass plate with the casting solution into 1.8g/L ZnO-Ag-TiO2Self-adhesive phase separation is carried out in aqueous solution;
4) and transferring the membrane after phase separation into deionized water to be soaked so as to remove redundant solvent, and then putting the membrane into clean deionized water for storage to obtain a PMIA mixed matrix membrane which is marked as an M5 ultrafiltration membrane.
Comparative example 1:
in the comparative example, a NIPS method was used to prepare a PMIA flat membrane using deionized water as a gel bath, and the specific preparation method was as follows:
1) dissolving LiCl and PMIA in DMAc in a mass ratio of 4:15, stirring for 10 hours at 60 ℃ until the LiCl and the PMIA are fully dissolved, and standing and defoaming for 6 hours to obtain a casting solution;
2) coating the casting solution on a glass plate in a scraping way, wherein the thickness of the scraped film is 250 mu m;
3) immersing the glass plate with the membrane liquid into deionized water for phase splitting;
4) and transferring the membrane after phase separation into deionized water to be soaked so as to remove redundant solvent, and then putting the membrane into clean deionized water for storage to obtain an unmodified PMIA flat membrane which is marked as an M0 ultrafiltration membrane.
The ultrafiltration membranes of examples 1 to 5 and comparative example were subjected to water flux and hexavalent chromium solution reduction tests, wherein the water flux and hexavalent chromium solution reduction test methods are described in the following references: wang, Gui-E Chen, Hai-Link Wu, contamination of GO-Ag/PMIA/F127 modified membrane IPA conjugation base for catalytic reduction of 4-nitrophenol, Sep.purif.Technol.235(2020) 116143. The results are shown in FIGS. 2 and 3, respectively, from which it can be seen that each of the membranes with added nanoparticles exhibited superior permeability and better separation performance compared to the original PMIA membrane. The permeability increase may be due to the influence of two main factors: the addition of nanoparticles imparts hydrophilicity to the membrane, thereby increasing the rate of water passage through the membrane
The improvement in catalytic reduction performance can be illustrated by the following reasons: 1) the surface charge of the film is mutually exclusive with the hexavalent chromium solution. 2) Under the irradiation of visible light, ZnO-Ag-TiO2The generated electrons are combined with dissolved oxygen to generate a large amount of superoxide radicals, and the superoxide radicals have extremely strong reducing capacity and can reduce hexavalent chromium into trivalent chromium which is convenient to treat.
The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.
Claims (10)
1. A method for preparing a PMIA mixed matrix membrane with photocatalytic performance by self-adhesion is characterized by comprising the following steps: hydrothermally synthesized ZnO-Ag-TiO with photocatalytic performance2The water solution of the nano composite material is used as a gel bath for the PMIA membrane to carry out non-solvent induced phase separation, and is self-adhered to the PMIA membrane in the non-solvent induced phase separation process, so that the nano particles are fixed on the surface of the membrane, and the PMIA mixed matrix membrane with the photocatalytic performance is obtained.
2. The method for preparing the photocatalytic PMIA mixed matrix membrane by self-adhesion according to claim 1, wherein the self-adhesion process comprises the following steps: the casting solution is immediately immersed in ZnO-Ag-TiO after being blade-coated2The self-adhesion of the photocatalyst is realized in the gel bath of (2).
3. The method for preparing the PMIA mixed matrix membrane with photocatalytic performance by self-adhesion according to claim 2, wherein the preparation method of the membrane casting solution comprises the following steps: and adding the cosolvent and PMIA into N, N-dimethylacetamide, uniformly stirring, standing and defoaming to obtain the membrane casting solution.
4. The method for preparing the PMIA mixed matrix membrane with photocatalytic performance by self-adhesion according to claim 3, wherein the content of a cosolvent in the membrane casting solution is 4.5g/L, and the content of PMIA is 12-20 g/L.
5. The method for preparing the PMIA mixed matrix membrane with photocatalytic performance by self-adhesion according to claim 3, wherein the cosolvent is LiCl;
and in the stirring process of the casting solution, the stirring temperature is 50-100 ℃, and the stirring time is 8-18 h.
6. The method for preparing a photocatalytic PMIA mixed matrix membrane by self-adhesion according to claim 1, characterized in that ZnO-Ag-TiO is in the gel bath2The concentration of the nano material is 0.2-1.8g/L。
7. The method for preparing photocatalytic PMIA mixed matrix membrane by self-adhesion according to claim 3, wherein the non-solvent induced phase separation method comprises: coating the casting solution on a substrate, and placing the substrate on ZnO-Ag-TiO2Carrying out phase separation in aqueous solution gel bath, and in the phase separation process, ZnO-Ag-TiO2And sticking the film to the surface of the film by self-adhesion to obtain the PMIA film with photocatalytic performance.
8. The method for preparing the PMIA mixed matrix membrane with photocatalytic performance by self-adhesion according to claim 7, wherein the blade coating thickness of the casting solution is 100-250 μm;
the temperature of the gel bath was 25 ℃.
9. A PMIA mixed matrix membrane with photocatalytic performance prepared by the method according to any one of claims 1 to 8.
10. Use of the PMIA mixed matrix membrane of claim 9 in catalytic degradation of dye wastewater.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110208117.9A CN112999889A (en) | 2021-02-25 | 2021-02-25 | Method for preparing PMIA mixed matrix membrane with photocatalytic performance by self-adhesion and application |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110208117.9A CN112999889A (en) | 2021-02-25 | 2021-02-25 | Method for preparing PMIA mixed matrix membrane with photocatalytic performance by self-adhesion and application |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112999889A true CN112999889A (en) | 2021-06-22 |
Family
ID=76385975
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110208117.9A Pending CN112999889A (en) | 2021-02-25 | 2021-02-25 | Method for preparing PMIA mixed matrix membrane with photocatalytic performance by self-adhesion and application |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112999889A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013191162A1 (en) * | 2012-06-20 | 2013-12-27 | 東洋アルミニウム株式会社 | Photocatalyst coating material, article, and photocatalyst coating material production method |
| CN106902650A (en) * | 2017-04-13 | 2017-06-30 | 淮阴师范学院 | A kind of antipollution automatically cleaning vinylidene difluoride planar ultrafiltration membrane and its preparation method and application |
| CN106944042A (en) * | 2017-02-22 | 2017-07-14 | 浙江大学 | A kind of core shell structure Ag/TiO2/ ZnO nano-wire and preparation method thereof |
| CN112121642A (en) * | 2020-09-14 | 2020-12-25 | 上海应用技术大学 | Poly (m-phenylene isophthalamide) water treatment membrane with photocatalytic self-cleaning performance and preparation method and application thereof |
| CN112295421A (en) * | 2020-10-20 | 2021-02-02 | 天津理工大学 | Surface-bonded TiO for photocatalysis2PVDF ultrafiltration membrane |
-
2021
- 2021-02-25 CN CN202110208117.9A patent/CN112999889A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013191162A1 (en) * | 2012-06-20 | 2013-12-27 | 東洋アルミニウム株式会社 | Photocatalyst coating material, article, and photocatalyst coating material production method |
| CN106944042A (en) * | 2017-02-22 | 2017-07-14 | 浙江大学 | A kind of core shell structure Ag/TiO2/ ZnO nano-wire and preparation method thereof |
| CN106902650A (en) * | 2017-04-13 | 2017-06-30 | 淮阴师范学院 | A kind of antipollution automatically cleaning vinylidene difluoride planar ultrafiltration membrane and its preparation method and application |
| CN112121642A (en) * | 2020-09-14 | 2020-12-25 | 上海应用技术大学 | Poly (m-phenylene isophthalamide) water treatment membrane with photocatalytic self-cleaning performance and preparation method and application thereof |
| CN112295421A (en) * | 2020-10-20 | 2021-02-02 | 天津理工大学 | Surface-bonded TiO for photocatalysis2PVDF ultrafiltration membrane |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Riaz et al. | An overview of TiO2-based photocatalytic membrane reactors for water and wastewater treatments | |
| Zheng et al. | Integration of a photo-Fenton reaction and a membrane filtration using CS/PAN@ FeOOH/g-C3N4Electrospun nanofibers: synthesis, characterization, self-cleaning performance and mechanism | |
| Shi et al. | Photocatalytic membrane in water purification: is it stepping closer to be driven by visible light? | |
| Li et al. | Ceramic nanocomposite membranes and membrane fouling: A review | |
| Iglesias et al. | Membrane-based photocatalytic systems for process intensification | |
| Yan et al. | In situ chemical oxidation: peroxide or persulfate coupled with membrane technology for wastewater treatment | |
| CN108159888B (en) | Preparation method of super-hydrophilic ultrafiltration membrane with photocatalytic performance | |
| Miao et al. | Continuous and complete conversion of high concentration p‐nitrophenol in a flow‐through membrane reactor | |
| CN112517071B (en) | Carbon nitride nanosheet-based photocatalytic composite membrane and preparation method and application thereof | |
| Xie et al. | Hydrophilic modification and anti-fouling properties of PVDF membrane via in situ nano-particle blending | |
| CN112121642A (en) | Poly (m-phenylene isophthalamide) water treatment membrane with photocatalytic self-cleaning performance and preparation method and application thereof | |
| CN113735337A (en) | Method for performing advanced treatment on difficultly-degradable pollutants by using conductive filter membrane-heterogeneous Fenton-like water treatment device | |
| CN109748360B (en) | Multifunctional hybrid ultrafiltration membrane, preparation method and application | |
| Chen et al. | Membrane-catalysis integrated system for contaminants degradation and membrane fouling mitigation: A review | |
| CN110975626B (en) | Preparation method of photo-Fenton catalytic self-cleaning super-hydrophilic PVDF ultrafiltration membrane | |
| CN112999874A (en) | Method for preparing PMIA mixed matrix membrane with photocatalytic performance by blending and application | |
| CN112121648A (en) | Polyvinylidene fluoride mixed matrix membrane with photocatalytic self-cleaning performance and preparation method and application thereof | |
| CN112999889A (en) | Method for preparing PMIA mixed matrix membrane with photocatalytic performance by self-adhesion and application | |
| CN112225382A (en) | Method for removing traditional Chinese medicine and personal care product in wastewater | |
| CN112090296A (en) | Based on F-TiO2/Fe-g-C3N4Self-cleaning flat plate type PVDF ultrafiltration membrane and preparation method thereof | |
| CN112569807A (en) | Polyvinylidene fluoride mixed matrix membrane with photocatalytic performance and preparation and application thereof | |
| Chowdhury et al. | Science and technology roadmap for photocatalytic membrane separation: a potential route for environmental remediation and fouling mitigation | |
| CN112569812A (en) | Poly (m-phenylene isophthalamide) mixed matrix membrane with photocatalytic performance and preparation and application thereof | |
| CN111715079B (en) | Multifunctional film material and preparation method and application thereof | |
| CN112569809A (en) | PMIA modified ultrafiltration membrane with photocatalytic performance and preparation and application thereof |
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 | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210622 |
|
| RJ01 | Rejection of invention patent application after publication |