Surface grafting and coating compound modification method for polyvinylidene fluoride membrane

A technology of polyvinylidene fluoride membrane and compound modification, which is applied in the direction of chemical instruments and methods, membrane, membrane technology, etc., can solve the problems of shortened membrane service life, short retention time, membrane pore clogging, etc., and achieves stable adhesion, improved Sexual effect is stable and not easy to fall off

Active Publication Date: 2017-09-29
WUHAN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the process of water treatment, the strong hydrophobicity of PVDF will cause two problems: one is that in order for water to pass through the membrane pores, a higher driving pressure is required
The second is that the membrane is easy to adsorb hydrophobic substances, such as protein and colloidal particles, which will cause the membrane pores to be blocked, the permeation flux will decrease, and the service life of the membrane will be shortened (Liu F, Hashim N A, Liu Y, et al. Progress in the production and modification of PVDF membranes[J].Fuel&Energy Abstracts,2011,375(1–2):1-27.), thus restricting the application of polyvinylidene fluoride membranes in aqueous phase separation systems
Its advantage is that it does not change the bulk performance of polyvinylidene fluoride membrane, but its disadvantage is that the hydrophilic effect is uncertain and the retention time is short

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] (1) Soak the polyvinylidene fluoride film in a solution dissolved in potassium hydroxide (1.0 wt%) and potassium permanganate (1.0 wt%), and react at 50° C. for 1 h.

[0025] (2) Take out the processed polyvinylidene fluoride film of (1), put into the solution that is dissolved with acrylamide (0.5wt%), potassium persulfate (0.5wt%), tannin (0.5wt%), adjust The pH of the solution was 7.8, soaked at 25°C for 10h.

[0026] (3) Take out the polyvinylidene fluoride membrane treated in (2) and clean it with deionized water to obtain a grafted / coated composite modified membrane.

Embodiment 2

[0028] (1) Soak the polyvinylidene fluoride film in a solution dissolved in potassium hydroxide (2.0 wt%) and potassium permanganate (1.0 wt%), and react at 60° C. for 1 h.

[0029] (2) Take out the treated polyvinylidene fluoride film of (1), put into the solution that is dissolved with acrylamide (1.0wt%), potassium persulfate (0.5wt%), tannin (1.0wt%), adjust The pH of the solution was 7.8, soaked at 30°C for 4h.

[0030] (3) Take out the polyvinylidene fluoride membrane treated in (2) and clean it with deionized water to obtain a grafted / coated composite modified membrane.

Embodiment 3

[0032] (1) Soak the polyvinylidene fluoride film in a solution dissolved in potassium hydroxide (1.0 wt%) and potassium permanganate (2.0 wt%), and react at 50° C. for 2 hours.

[0033] (2) Take out the treated polyvinylidene fluoride film of (1), put into the solution that is dissolved with acrylamide (2.0wt%), potassium persulfate (1.0wt%), tannin (2.0wt%), adjust The pH of the solution was 8.1, soaked at 40°C for 3h.

[0034] (3) Take out the polyvinylidene fluoride membrane treated in (2) and clean it with deionized water to obtain a grafted / coated composite modified membrane.

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Abstract

The invention relates to a surface grafting and coating compound modification method for a polyvinylidene fluoride membrane. The method comprises the following steps: generating a grafting point on the surface of the polyvinylidene fluoride membrane under a mild grafting modification condition without influencing the mechanical performance of the membrane; polymerizing a hydrophilic monomer on the surface of the membrane to form a hydrophilic grafted high-molecular chain, wherein the grafted high-molecular chain plays a role in anchoring on the surface of the membrane; finally, self-polymerizing and depositing polyphenol, and hybridizing the hydrophilic grafted high-molecular chain to form a hydrophilic coating layer. Under the anchoring effect of the grafted high-molecular chain between the coating layer and the membrane, the polyvinylidene fluoride membrane is attached stably, is prevented from falling easily, and has a good modification effect.

Description

technical field [0001] The invention relates to the technical field of polymer film surface modification, in particular to a polyvinylidene fluoride film surface grafting / coating composite modification method. Background technique [0002] Polyvinylidene fluoride (PVDF) is a linear semi-crystalline polymer with excellent mechanical properties, heat resistance, acid and alkali corrosion resistance, impact resistance, not easy to degrade, easy to form a film, etc. One of the preferred materials for membranes. However, due to its extremely low surface energy and no hydrogen bond interaction with water, it has strong hydrophobicity (Jing J, Fu L, Hashim N A, et al. Poly(vinylidene fluoride) (PVDF) membranes for fluid separation[J ]. Reactive & Functional Polymers, 2014, 86:134-153.). In the process of water treatment, the strong hydrophobicity of PVDF will cause two problems: one is that in order to make water pass through the membrane pores, a higher driving pressure is requi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01D71/34B01D67/00B01D69/12
CPCB01D67/0093B01D69/12B01D69/125B01D71/34B01D2323/38B01D2323/46B01D2325/24B01D2325/30B01D2325/36
Inventor 吴力立赵德鹏张松峰张超灿
Owner WUHAN UNIV OF TECH
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