CN116282443B - Application of polyacrylamide brush as water treatment flocculant - Google Patents
Application of polyacrylamide brush as water treatment flocculant Download PDFInfo
- Publication number
- CN116282443B CN116282443B CN202310319863.4A CN202310319863A CN116282443B CN 116282443 B CN116282443 B CN 116282443B CN 202310319863 A CN202310319863 A CN 202310319863A CN 116282443 B CN116282443 B CN 116282443B
- Authority
- CN
- China
- Prior art keywords
- polyacrylamide
- silicon wafer
- brush
- water treatment
- initiator
- 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
- 229920002401 polyacrylamide Polymers 0.000 title claims abstract description 68
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 44
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 12
- 239000000463 material Substances 0.000 claims abstract description 7
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 51
- 229910052710 silicon Inorganic materials 0.000 claims description 51
- 239000010703 silicon Substances 0.000 claims description 51
- 239000003999 initiator Substances 0.000 claims description 30
- 238000006116 polymerization reaction Methods 0.000 claims description 29
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 claims description 21
- 239000000758 substrate Substances 0.000 claims description 16
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 13
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 8
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 8
- 238000006243 chemical reaction Methods 0.000 claims description 8
- 238000005406 washing Methods 0.000 claims description 8
- 229910052757 nitrogen Inorganic materials 0.000 claims description 7
- 238000001338 self-assembly Methods 0.000 claims description 7
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 claims description 6
- 239000008367 deionised water Substances 0.000 claims description 6
- 229910021641 deionized water Inorganic materials 0.000 claims description 6
- ROFVEXUMMXZLPA-UHFFFAOYSA-N Bipyridyl Chemical compound N1=CC=CC=C1C1=CC=CC=N1 ROFVEXUMMXZLPA-UHFFFAOYSA-N 0.000 claims description 4
- 239000012153 distilled water Substances 0.000 claims description 4
- 238000001035 drying Methods 0.000 claims description 4
- 239000007788 liquid Substances 0.000 claims description 4
- 238000000034 method Methods 0.000 claims description 4
- 239000000126 substance Substances 0.000 claims description 4
- SNYHRPNTNQYJMD-UHFFFAOYSA-N trichloro(1-chloropropyl)silane Chemical compound CCC(Cl)[Si](Cl)(Cl)Cl SNYHRPNTNQYJMD-UHFFFAOYSA-N 0.000 claims description 4
- 238000002360 preparation method Methods 0.000 claims description 3
- GAWAYYRQGQZKCR-UHFFFAOYSA-N 2-chloropropionic acid Chemical compound CC(Cl)C(O)=O GAWAYYRQGQZKCR-UHFFFAOYSA-N 0.000 claims description 2
- 229960002089 ferrous chloride Drugs 0.000 claims description 2
- 238000007710 freezing Methods 0.000 claims description 2
- 230000008014 freezing Effects 0.000 claims description 2
- NMCUIPGRVMDVDB-UHFFFAOYSA-L iron dichloride Chemical compound Cl[Fe]Cl NMCUIPGRVMDVDB-UHFFFAOYSA-L 0.000 claims description 2
- 239000000203 mixture Substances 0.000 claims description 2
- 239000003921 oil Substances 0.000 claims description 2
- 230000008569 process Effects 0.000 claims description 2
- 239000002904 solvent Substances 0.000 claims description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N sulfuric acid Substances OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 2
- 238000009210 therapy by ultrasound Methods 0.000 claims description 2
- 125000004122 cyclic group Chemical group 0.000 claims 1
- 238000010438 heat treatment Methods 0.000 claims 1
- 238000005086 pumping Methods 0.000 claims 1
- 238000007711 solidification Methods 0.000 claims 1
- 230000008023 solidification Effects 0.000 claims 1
- 238000004506 ultrasonic cleaning Methods 0.000 claims 1
- 238000003911 water pollution Methods 0.000 abstract description 5
- 239000003153 chemical reaction reagent Substances 0.000 abstract description 4
- 229920000642 polymer Polymers 0.000 description 19
- 230000000694 effects Effects 0.000 description 12
- 238000005189 flocculation Methods 0.000 description 11
- 230000016615 flocculation Effects 0.000 description 10
- 239000000243 solution Substances 0.000 description 10
- 238000004062 sedimentation Methods 0.000 description 9
- 230000015572 biosynthetic process Effects 0.000 description 6
- 239000003054 catalyst Substances 0.000 description 5
- CMDGQTVYVAKDNA-UHFFFAOYSA-N propane-1,2,3-triol;hydrate Chemical compound O.OCC(O)CO CMDGQTVYVAKDNA-UHFFFAOYSA-N 0.000 description 5
- 238000009826 distribution Methods 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 239000012046 mixed solvent Substances 0.000 description 4
- 239000010865 sewage Substances 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 230000009471 action Effects 0.000 description 3
- 238000010560 atom transfer radical polymerization reaction Methods 0.000 description 3
- 238000004140 cleaning Methods 0.000 description 3
- 238000002329 infrared spectrum Methods 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 230000035484 reaction time Effects 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 238000000026 X-ray photoelectron spectrum Methods 0.000 description 2
- 238000002835 absorbance Methods 0.000 description 2
- 125000003368 amide group Chemical group 0.000 description 2
- 239000003125 aqueous solvent Substances 0.000 description 2
- 238000000089 atomic force micrograph Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 125000002915 carbonyl group Chemical group [*:2]C([*:1])=O 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000003993 interaction Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 239000000178 monomer Substances 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- 238000004065 wastewater treatment Methods 0.000 description 2
- 239000005995 Aluminium silicate Substances 0.000 description 1
- 239000002841 Lewis acid Substances 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 235000012211 aluminium silicate Nutrition 0.000 description 1
- 150000001408 amides Chemical class 0.000 description 1
- 125000003277 amino group Chemical group 0.000 description 1
- 239000008346 aqueous phase Substances 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 238000000149 argon plasma sintering Methods 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- 239000000084 colloidal system Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 239000003651 drinking water Substances 0.000 description 1
- 235000020188 drinking water Nutrition 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000004108 freeze drying Methods 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 150000007517 lewis acids Chemical class 0.000 description 1
- 229920002521 macromolecule Polymers 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 231100000956 nontoxicity Toxicity 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 239000003505 polymerization initiator Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000036632 reaction speed Effects 0.000 description 1
- 238000006479 redox reaction Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 239000010802 sludge Substances 0.000 description 1
- 238000004611 spectroscopical analysis Methods 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- ZSDSQXJSNMTJDA-UHFFFAOYSA-N trifluralin Chemical compound CCCN(CCC)C1=C([N+]([O-])=O)C=C(C(F)(F)F)C=C1[N+]([O-])=O ZSDSQXJSNMTJDA-UHFFFAOYSA-N 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Classifications
-
- 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
- C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
- C02F1/54—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using organic material
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Abstract
The invention discloses an application of a polyacrylamide brush as a water treatment flocculant, wherein the polyacrylamide brush comprises a base material and a polyacrylamide molecular chain segment planted on the surface of the base material. The invention adopts the polyacrylamide brush as the water treatment flocculant, which not only can show excellent treatment performance, but also is easy to operate and periodically replace compared with the traditional powdery or gelatinous polyacrylamide flocculant, and avoids secondary water pollution possibly caused by taking the powdery or gelatinous polyacrylamide water treatment agent as a chemical reagent.
Description
Technical Field
The invention relates to a high molecular polymer brush, in particular to an application of a polyacrylamide brush as a water treatment flocculant.
Background
Flocculation precipitation is an important place in water industry and wastewater treatment. As the most commonly used organic polymeric flocculant, polyacrylamide (PAM) and derivatives thereof have good water solubility, good flocculation performance and adsorption performance due to a large amount of amido on a molecular chain, and unique biocompatibility and non-toxicity, so that the application functions of the PAM and derivatives thereof are fully shown in other fields such as purification of drinking water, treatment of waste water and the like.
The traditional flocculant polyacrylamide is generally used in a 'free' state (such as powder and colloid) in water industry and wastewater treatment, and the action mechanism is an adsorption bridging theory, according to the theory, the polymer with bridging action is linear molecules, and a length is needed, and the bridging action between the particles cannot be constructed if the length is insufficient, so that the flocculant has a great relationship with the molecular structure of a product.
In contrast, a flocculant with a larger molecular weight has more adsorptivity in the flocculation process, and the effect is stronger, and the low molecular weight of the flocculant determines the selling price and the application performance of the flocculant.
Flocculation is an extremely complex process, and the effect is affected by a plurality of reasons, such as temperature, pH value, addition amount and the like, which are all required to be tested. In general, the molecular weight mainly influences the size of the flocculation group of the 'free' flocculant, and the larger the molecular weight is, the larger the flocculation group is, and the sedimentation speed is high, so the flocculant is generally selected for centrifugal dehydration or flocculation sedimentation; however, if the molecular weight is too large, the adverse effects such as slow reaction speed, long reaction time, non-drying of dehydrated sludge and the like are caused. As the inventors have studied earlier (Gu Xiaolong, jiang Jianguo. Synthesis of polyacrylamide as a water treatment flocculant with narrow molecular weight distribution and stereoregularity [ J ]. Macromolecular report, 2014, 6, 81-87), polyacrylamide as a "free" flocculant with a larger molecular weight, has a longer chain segment, and when flocculation treatment is performed, a flocculant with the same concentration and a larger molecular weight brings a larger viscosity to the treatment system, and is unfavorable for the generation of flocculation effect; on the other hand, the "free" flocculant has excessively long chain segments, which show a random coil conformation in an aqueous solution, and when some sewage mixed with oily substances is treated, the excessively long molecular chains are more likely to curl, and the treatment effect is also reduced. Therefore, it is also necessary to control the index of molecular weight distribution, stereoregularity, etc. of the "free" form polyacrylamide, for example, by introducing Lewis acids as a directional polymerization controlling agent into the polymerization system, respectively. However, the method for preparing the polyacrylamide has large industrial production difficulty and high cost, and the dosage is still required to be strictly controlled in application so as to avoid secondary water pollution possibly caused by taking the polyacrylamide as a chemical reagent.
Disclosure of Invention
Aiming at the problems that the dosage of the free polyacrylamide flocculant is strictly controlled and secondary water pollution possibly exists, the invention provides the application of the polyacrylamide brush as the water treatment flocculant, and the application adopts the polyacrylamide brush as the water treatment agent, so that the operation and the periodic replacement are easy, and the secondary water pollution possibly caused by taking the polyacrylamide water treatment agent as a chemical reagent is avoided.
In order to achieve the above object, the present invention provides an application of a polyacrylamide brush as a flocculant for water treatment.
Specifically, the polyacrylamide brush comprises a substrate and a polyacrylamide molecular chain segment planted on the surface of the substrate.
Specifically, the preparation method of the polyacrylamide brush comprises the following steps:
s1, placing a substrate in an initiator, standing, cleaning and drying to obtain the substrate with the surface self-assembled with the initiator;
s2, mixing an acrylamide monomer, a catalyst and a substrate with an initiator self-assembled on the surface, freeze-drying, vacuumizing and evacuating, and performing polymerization reaction at 80-130 ℃.
Preferably, in step S1, the standing time is 18 to 20 hours.
Preferably, prior to step S1, the substrate is subjected to the following pretreatment: removing residual substances on the surface in HF solution after cleaning, washing with water, and placing in H 2 SO 4 And H 2 O 2 Ultrasonic etching is carried out in the mixed solution, and then cleaning is carried out again.
In view of the difficulty in obtaining the molecular weight of the polymer brush directly, a "free" initiator is added to the polymerization system to simultaneously initiate polymerization of the monomers to give a "free" polymer. The molecular weight or other physical index of the resulting "free" polymer is measured and can be indicative of the progress of the brush growth. On the other hand, since initiator groups deposit on heterogeneous substrate surfaces with lower surface areas, in systems for preparing polymer brushes by surface initiated atom transfer radical polymerization, the surface initiated polymerization reaction in the system is further complicated by the low concentration of initiator and the lower number of permanent radicals (deactivators) generated after initiator activation. The addition of "free" initiator promotes the formation of more deactivated species by oxidation-reduction reactions in the polymerization solution, thereby ensuring a sufficient amount of deactivated species throughout the polymerization process to maintain a relatively stable low concentration of reactive radicals.
Of course, the polyacrylamide brush and the "free" polyacrylamide may also be prepared separately.
Preferably, in step S2, a "free" polymerization initiator is also added to the mixed reaction system.
Through the technical scheme, the invention has the following beneficial effects:
1. the invention adopts the polyacrylamide brush as the water treatment flocculant, which not only can show excellent treatment performance, but also is easy to operate and periodically replace compared with the traditional powdery or gelatinous polyacrylamide flocculant, thereby avoiding secondary water pollution possibly caused by taking the powdery or gelatinous polyacrylamide water treatment agent as a chemical reagent.
2. The invention adopts a surface initiation-atom transfer radical polymerization method to realize 'planting' macromolecular brushes on the surface of a substrate, firstly, self-assembly of initiator molecules is carried out on the surface of the substrate, the self-assembly serves as a polymerization active point to initiate monomer acrylamide to polymerize, one end of a synthesized brush polymer chain is bonded to the surface of the material in a covalent bond mode, the other end of the brush polymer chain can freely move in the solution, more interactions with related components in target sewage can be realized, the high molecular weight of the brush polymer chain is favorable for improving the water treatment effect, the defect that the viscosity increase caused by the high molecular weight of the polyacrylamide of a 'free' water treatment agent is unfavorable for flocculation effect is avoided, and the effect advantage of the macromolecular material serving as a water treatment agent is fully exerted.
Drawings
FIG. 1 is an XPS spectrum of an initiator layer self-assembled on a silicon wafer surface in an embodiment of the invention;
FIG. 2 is an infrared spectrum of a polyacrylamide brush formed on a silicon surface in an embodiment of the present invention;
FIG. 3 is an XPS spectrum of a polyacrylamide brush prepared in an example of the present invention;
FIG. 4 is an AFM image of a polyacrylamide brush made at various temperatures in an example of the present invention: (a) a polyacrylamide brush obtained at a polymerization temperature of 80 ℃; (b) a polyacrylamide brush obtained at a polymerization temperature of 130 ℃.
Detailed Description
The following describes specific embodiments of the present invention in detail with reference to examples. It should be understood that the detailed description and specific examples, while indicating and illustrating the invention, are not intended to limit the invention.
Examples
1. Preparation of polyacrylamide brush
1) Pretreatment of substrate silicon wafer
The silicon wafer (111) (3 cm x 1 cm) is washed by ultrasonic for 5 minutes, rinsed by acetone, ethanol and deionized water in sequence, and then placed in 5% HF solution to remove the surface residual substances. After washing with distilled water, the silicon wafer is placed in 98% concentrated sulfuric acid and 30% H 2 O 2 The volume ratio (v/v) is 70:30, and ultrasonic treatment was carried out for 45 minutes. And taking out the silicon wafer, and washing the silicon wafer with a large amount of deionized water to obtain the hydrophilic silicon wafer.
2) Self-assembly of initiators on silicon surfaces
The pretreated hydrophilic silicon wafer is put into 10ml toluene solution containing 5 mu L of initiator 1-chloropropyl trichlorosilane, and is taken out after standing for 18 hours, and is ultrasonically washed for 1 minute by toluene, then is washed by toluene, acetone and ethanol in sequence, and the silicon wafer is dried by nitrogen flow for standby.
3) Polyacrylamide brush for planting macromolecular water treatment agent on silicon surface
Mixing ferrous chloride, bipyridine, acrylamide, solvent water or mixed solvent of glycerin-water (1:1 v/v) with the molar ratio of 1:2:50:50, and silicon wafer with self-assembled initiator on the surface (polymerization reaction in water phase with polymerization temperature of 80 ℃ or mixed solvent of glycerin-water (1:1 v/v) with polymerization temperature of 130 ℃), wherein the raw materials are as follows] 0 Initiator/[ initiator ]] 0 Catalyst/[ catalyst] 0 ,/[ bipyridyl ]] 0 =50:1:1:2) and initiator α -chloropropionic acid for "free" polymerization (molar ratio to initiator 1-chloropropyl trichlorosilane 1: 1) Sequentially adding the components into a clean reaction tube. The sealed reaction tube was heated in a constant temperature oil bath of 80 ℃ (aqueous solvent) or 130 ℃ (mixing in a glycerol-water volume ratio of 1:1) through three cycles of liquid nitrogen freezing to solidify-vacuum pump-nitrogen introduction. After a certain period of polymerization (in an aqueous solvent, the reaction temperature is 80 ℃, the reaction time is 48 hours, and in a mixed solvent with the glycerol-water volume ratio of 1:1, the reaction temperature is 130 ℃, the reaction time is 14 hours), the polymerization tube is taken out, and the sealing plug is opened, so that the polymerization system is exposed in the air to stop the polymerization reaction. Pouring out a part of the solution in the polymerization tube, diluting in water, precipitating with methanol, and drying the free polyacrylamide polymer obtained by centrifugal separation in a vacuum oven at 40 ℃ for 24 hours for GPC (GPC) determination of molecular weight and comparative sedimentation test; after the silicon wafer in the polymerization tube is taken out, a large amount of distilled water is used for washing, and then the silicon wafer is soaked in deionized water for one day to remove free polyacrylamide adsorbed on the surface of the silicon wafer.
2. Characterization method
The infrared spectrogram of the surface of the silicon wafer is obtained by testing a Bio-Rad FTS 3000 instrument, an MCT detector is attached, a transmission mode is adopted, and liquid nitrogen is frozen;
AFM testing was performed on an SPL3800N instrument equipped with BS-Tap300AI CANTILEVER;
contact angle data were obtained from measurements on an instrument Dataphysics, OCA15plus at room temperature (Dataphysics Instruments, gmbH, germany), wetting liquid deionized water, resistivity 18M Ω/m;
the information of the surface of the silicon wafer and the composition of the polymer brush is obtained by an X-ray photoelectron spectrogram, and a VG-Scientific Mg-KR X-ray source is adopted;
the polymer molecular weight and molecular weight distribution width were determined by Wyatt gel chromatograph (GPC) equipped with TRI STAR MINIDAWN light scattering detector and SHOWA DENKOK.K. Shodex R1-71 differential refractometer, two Shodex OHPak SB-806M HQ columns; PEG and PEO (available from Wyatt corporation) were used as standard samples; 0.1 mol/dm 3 NaNO 3 /CH 3 The solution of CN (V/V=3:1) is a mobile phase, and the flow rate is 0.5 ml/min; all samples were tested at 25 ℃.
In order to prepare the polyacrylamide brush on the surface of a substrate silicon wafer, a silicon wafer with a uniform surface and self-assembled initiator molecules is indispensable. The silicon wafer after the clean pretreatment is subjected to self-assembly of initiator molecules in toluene solution containing 1-chloropropyl trichlorosilane. The water contact angle of the self-assembled silicon surface of the initiator molecule reaches 86.5 degrees, which is far higher than the contact angle of 41 degrees of the silicon wafer, and the initiator molecule shows very high hydrophobicity.
The formation of an initiator monolayer on the silicon surface can be further confirmed by XPS on the silicon surface after self-assembly of the initiator molecules. As shown in fig. 1, at position 204.95 eV, there is a Cl 2p peak present.
The results obtained by carrying out acrylamide polymerization on the silicon surface are shown in table 1. The molecular weight distribution width of the free polyacrylamide is 1.23-1.31, which shows the activity characteristic of the polymerization reaction. The contact angles of the obtained silicon wafer growing with the polyacrylamide brush are 58.8 degrees and 44.0 degrees respectively at the polymerization temperature of 80 ℃ or 130 ℃, which are far lower than the contact angle of the silicon wafer after self-assembly initiator by 86.5 degrees, which indicates that the hydrophilicity of the silicon surface is increased due to the formation of the polyacrylamide brush on the silicon wafer surface. The numerical difference between 58.8 ° and 44.0 ° is due to the difference in length of the resulting polyacrylamide chains at the two polymerization temperatures. Because the longer the polyacrylamide chain, the more hydrophilic groups there are on the molecular chain, the lower the contact angle is.
TABLE 1 polymerization results and Water contact Angle data of Polyacrylamide brush on silicon wafer surface a
a Polymerization in aqueous phase at 80℃or mixed solvent of glycerin-water (1:1 v/v) at 130℃to give acrylamide] 0 Initiator/[ initiator ]] 0 Catalyst/[ catalyst] 0 ,/[ bipyridyl ]] 0 ＝50:1:1:2；
b GPC data were measured by Wyatt gel chromatograph.
FIG. 2 shows an infrared spectrum of a "planted" polyacrylamide brush on a silicon surface. All maps are 3100-3500 cm -1 A broad peak (stretching vibration of amino group) appears in the region, 1665 cm -1 And 1615 cm -1 Two peaks (a carbonyl peak on the amide and a peak where the carbonyl group forms an H bond with the amide group) appear, whereby the formation of the polymer polyacrylamide on the silicon wafer can be confirmed.
In addition to the infrared spectrum and contact angle test methods already employed above, the formation of a polyacrylamide brush on the substrate silicon wafer surface was further confirmed by XPS spectroscopy: the N1 s peak appears at 405.7eV (as shown in fig. 3).
FIG. 4 shows AFM images of the initiation of atom transfer radical polymerization on a silicon surface to produce a polyacrylamide brush.
3. Water treatment experiment (sedimentation experiment)
200mL of kaolin solution containing a certain amount of greasy dirt is filled in a measuring cup with a cover, and after standing for a period of time, the absorbance A is measured in a 721 type spectrophotometer at the wavelength of 550 nm; then, at room temperature of 25 ℃, a sedimentation experiment is carried out by using a base material which is prepared at the polymerization temperature of 80 ℃ or 130 ℃ and is planted with the high-molecular water treatment agent polyacrylamide and synchronously synthesizing to obtain the free polyacrylamide, wherein the free polyacrylamide is prepared into a concentration with the mass fraction of 1%, the free polyacrylamide is fully swayed and turned over for 20 times, then is kept for the same time, the absorbance B is measured, and the sedimentation rate (sedimentation rate eta= (A-B)/A) is calculated, and the result is shown in a table 2.
TABLE 2 data results of sedimentation experiments with Polyacrylamide brushes and "free" Polyacrylamide
As can be seen from Table 2, for the "free" water treatment agent polyacrylamide, too high a molecular weight is detrimental to sedimentation efficiency, while for the "planted" polymer brush polyacrylamide on the substrate surface, a high molecular weight is beneficial to improving its water treatment effect. On the one hand, the high molecular weight of the polyacrylamide brush planted on the surface of the substrate has little influence on the viscosity of a water treatment system, and the defect that the flocculation effect is not facilitated due to the viscosity increase caused by the high molecular weight of the polyacrylamide of the free water treatment agent is avoided. On the other hand, as the polymer brush planted on the surface of the substrate is a linear polymer chain segment, the higher the molecular weight of the polymer brush, the longer the chain segment of the planted linear polymer, so that the polymer brush can have more interaction with related components in the target sewage; in addition, the longer macromolecule chain segments provide possibility for the synergistic effect among the chain segments, so that more effective treatment effect on sewage can be achieved.
The preferred embodiments of the present invention have been described in detail above with reference to the examples, but the present invention is not limited to the specific details of the above embodiments, and various simple modifications can be made to the technical solutions of the present invention within the scope of the technical concept of the present invention, and all the simple modifications belong to the protection scope of the present invention.
In addition, the specific features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various possible combinations are not described further.
Moreover, any combination of the various embodiments of the invention can be made without departing from the spirit of the invention, which should also be considered as disclosed herein.
Claims (1)
1. The application of the polyacrylamide brush as a water treatment flocculant is characterized in that the polyacrylamide brush comprises a base material and a polyacrylamide molecular chain segment planted on the surface of the base material, and the preparation method of the polyacrylamide brush comprises the following steps:
1) Pretreatment of substrate silicon wafer
After ultrasonic cleaning of the silicon wafer for 5 minutes, sequentially eluting the silicon wafer by acetone, ethanol and deionized waterThen the mixture is put into 5 percent HF solution to remove the residual substances on the surface; after washing with distilled water, the silicon wafer is placed in 98% concentrated sulfuric acid and 30% H 2 O 2 The volume ratio is 70:30, and performing ultrasonic treatment for 45 minutes; taking out the silicon wafer, and washing the silicon wafer with a large amount of deionized water to obtain a hydrophilic silicon wafer;
2) Self-assembly of initiators on silicon surfaces
Putting the pretreated hydrophilic silicon wafer into 10ml of toluene solution containing 5 mu L of initiator 1-chloropropyl trichlorosilane, standing for 18 hours, taking out, ultrasonically washing with toluene for 1 minute, then washing with toluene, acetone and ethanol in sequence, and drying the silicon wafer with nitrogen flow for later use;
3) Polyacrylamide brush for planting macromolecular water treatment agent on silicon surface
Ferrous chloride, bipyridine, acrylamide, a solvent, a silicon wafer with a self-assembled initiator on the surface and an initiator alpha-chloropropionic acid for free polymerization are sequentially added into a clean reaction tube in a molar ratio of 1:2:50:50, the cyclic process of solidification, vacuum pumping and nitrogen introducing is carried out through three liquid nitrogen freezing, the sealed reaction tube is placed into a constant-temperature oil bath at 130 ℃ for heating reaction for 14h, the silicon wafer is taken out, and after the silicon wafer is washed by distilled water, the silicon wafer is soaked in deionized water for one day to remove free polyacrylamide adsorbed on the surface of the silicon wafer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310319863.4A CN116282443B (en) | 2023-03-29 | 2023-03-29 | Application of polyacrylamide brush as water treatment flocculant |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310319863.4A CN116282443B (en) | 2023-03-29 | 2023-03-29 | Application of polyacrylamide brush as water treatment flocculant |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN116282443A CN116282443A (en) | 2023-06-23 |
| CN116282443B true CN116282443B (en) | 2023-11-03 |
Family
ID=86825649
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310319863.4A Active CN116282443B (en) | 2023-03-29 | 2023-03-29 | Application of polyacrylamide brush as water treatment flocculant |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116282443B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101638261A (en) * | 2009-06-13 | 2010-02-03 | 山东国信水处理有限公司 | Starch-based quaternary ammonium salt green flocculant and preparation method |
| CN102731143A (en) * | 2011-04-13 | 2012-10-17 | 西北师范大学 | Preparation method of silicon substrate capable of carrying out hydrophilic and hydrophobic reversible transition |
| CN103421204A (en) * | 2013-08-20 | 2013-12-04 | 常州大学 | Surface-amphiphilic polyester film and preparation method thereof |
| CN114907586A (en) * | 2022-07-05 | 2022-08-16 | 南京工业大学 | Cellulose hydrogel for adsorbing dye and preparation method thereof |
-
2023
- 2023-03-29 CN CN202310319863.4A patent/CN116282443B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101638261A (en) * | 2009-06-13 | 2010-02-03 | 山东国信水处理有限公司 | Starch-based quaternary ammonium salt green flocculant and preparation method |
| CN102731143A (en) * | 2011-04-13 | 2012-10-17 | 西北师范大学 | Preparation method of silicon substrate capable of carrying out hydrophilic and hydrophobic reversible transition |
| CN103421204A (en) * | 2013-08-20 | 2013-12-04 | 常州大学 | Surface-amphiphilic polyester film and preparation method thereof |
| CN114907586A (en) * | 2022-07-05 | 2022-08-16 | 南京工业大学 | Cellulose hydrogel for adsorbing dye and preparation method thereof |
Non-Patent Citations (2)
| Title |
|---|
| Preparation and performance of cationic flocculant for papermakingbased on the graft polymerization of cationic chains from colloidalsilica particles;Xiongzhi Zhang等;Colloids and Surfaces A: Physicochemical and Engineering Aspects;第491卷;29-36 * |
| Xiongzhi Zhang等.Preparation and performance of cationic flocculant for papermakingbased on the graft polymerization of cationic chains from colloidalsilica particles.Colloids and Surfaces A: Physicochemical and Engineering Aspects.2015,第491卷29-36. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN116282443A (en) | 2023-06-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Harada et al. | Polymeric rotaxanes | |
| Li et al. | Preparation and characterization of poly (acrylonitrile-acrylic acid-N-vinyl pyrrolidinone) terpolymer blended polyethersulfone membranes | |
| US10125222B2 (en) | Method for the preparation of high molecular weight oligo(alkylene glycol) functionalized polyisocyanopeptides | |
| Wu et al. | Modification of aromatic polyamide thin-film composite reverse osmosis membranes by surface coating of thermo-responsive copolymers P (NIPAM-co-Am). I: Preparation and characterization | |
| Arkas et al. | Organosilicon dendritic networks in porous ceramics for water purification | |
| Gurbuz et al. | Synthesis of cationic N‐[3‐(dimethylamino) propyl] methacrylamide brushes on silicon wafer via surface‐initiated RAFT polymerization | |
| CN105884988B (en) | The adjustable high perforation hexagonal columnar film of P4VP-b-PMA (Az) block copolymer, column diameter and preparation method | |
| Zhuang et al. | Protein resistant properties of polymers with different branched architecture on a gold surface | |
| Dong et al. | Antibacterial surfaces based on poly (cationic liquid) brushes: switchability between killing and releasing via anion counterion switching | |
| Hall-Edgefield et al. | Hybrid molecular brushes with chitosan backbone: facile synthesis and surface grafting | |
| Demirci et al. | RAFT-mediated synthesis of cationic poly [(ar-vinylbenzyl) trimethylammonium chloride] brushes for quantitative DNA immobilization | |
| Verma et al. | Grafting of N-(hydroxymethyl) acrylamide on to κ-carrageenan: synthesis, characterization and applications | |
| Mao et al. | OEGylated cyclodextrin-based thermoresponsive polymers and their switchable inclusion complexation with fluorescent dyes | |
| Cha et al. | Preparation and characterization of dendrimer layers on poly (dimethylsiloxane) films | |
| CN116282443B (en) | Application of polyacrylamide brush as water treatment flocculant | |
| Dzhardimalieva et al. | Synthetic methodologies for chelating polymer ligands: recent advances and future development | |
| CN108586681B (en) | Block copolymer aqueous hyperdispersant and preparation method thereof | |
| Cao et al. | Synthesis and antifouling performance of tadpole-shaped poly (N-hydroxyethylacrylamide) coatings | |
| Cimen et al. | Synthesis of dual‐functional poly (6‐azidohexylmethacrylate) brushes by a RAFT agent carrying carboxylic acid end groups | |
| Loudy et al. | Revealing surface functionalities via microwave for the para-fluoro-Thiol click reaction | |
| Price et al. | Piezoelectric chemical sensors based on morpholine containing polymers | |
| Suprapto et al. | The effect of synthesis condition of the ability of swelling, adsorption, and desorption of zwitterionic sulfobetaine-based gel | |
| Mielańczyk et al. | Synthesis and self-assembly behavior of amphiphilic methyl α-D-glucopyranoside-centered copolymers | |
| EP4065616B1 (en) | Polymer conetworks of poly(pyridine-(meth)-acrylamide) derivatives-crosslinked by transition metal ions- and linked by polydimethylsiloxane derivatives | |
| CN110655608B (en) | Polar polymer microparticles, preparation method 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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |