Method for performing surface modification on polytetrafluoroethylene separation membrane

A polytetrafluoroethylene and surface modification technology, used in semi-permeable membrane separation, chemical instruments and methods, membrane technology, etc., can solve the problems of poor hydrophilicity of PTFE separation membrane, easy pollution of modification process, and low flux. , to improve the anti-pollution ability, the method is simple and practical, and the retention rate is improved.

Inactive Publication Date: 2012-04-25
NANJING UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to provide a simple and efficient method for surface modification of polytetrafluoroethylene separation membranes

Method used

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  • Method for performing surface modification on polytetrafluoroethylene separation membrane
  • Method for performing surface modification on polytetrafluoroethylene separation membrane
  • Method for performing surface modification on polytetrafluoroethylene separation membrane

Examples

Experimental program
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Effect test

Embodiment 1

[0027] Embodiment 1: respectively adopt trimethyl aluminum (TMA), deionized water (H 2 O) as the precursor, high-purity nitrogen (N 2 ) as carrier and sweep gas. The pulse time of both precursors is 0.015s, the precursor exposure time is 10s, the cleaning time is 20s, and the carrier gas flow rate is 10sccm. Heat the temperature of the reaction chamber to 180°C, keep the membrane at the set temperature of the reaction chamber for 20 minutes, and prepare modified membranes with 10, 20, 50, 100, 200, 300, and 500 cycles respectively.

[0028] Depend on figure 1 It can be seen that with the increase of the deposition times, the alumina particles in the membrane pores and on the surface gradually become larger, and the pore diameter of the membrane gradually decreases regularly, realizing the continuous adjustment of the pore diameter.

[0029] Depend on figure 2 It can be seen that from 10 cycles to 100 cycles, the contact angle does not change much and is basically about 13...

Embodiment 2

[0032] Embodiment 2: respectively adopt titanium tetrachloride (TiCl 4 ), deionized water (H 2 O) is the precursor, and high-purity argon (Ar) is used as the carrier gas and sweep gas. TiCl 4 The pulse time is 0.3s, H 2 The O pulse time is 0.015s, the precursor exposure time is 0s, the cleaning time is 5s, and the carrier gas flow rate is 20 sccm. Heat the temperature of the reaction chamber to 150°C, keep the membrane at the set temperature of the reaction chamber for 50 minutes, and prepare modified membranes with 200, 400, 800, 850, 900, 950, 1000, and 1300 cycles respectively.

[0033] Depend on Figure 5 It can be seen that the deposition of TiO on the PTFE film 2After that, the hydrophilicity changed significantly. From 0 cycles to 400 cycles, the contact angle does not change much, basically between 130° and 120°; when the deposition reaches 800 times, the contact angle becomes smaller to 112°; then as the deposition progresses, the contact angle changes Suddenly...

Embodiment 3

[0036] Embodiment 3: respectively adopt trimethyl aluminum (TMA), deionized water (H 2 O) as the precursor, high-purity nitrogen (N 2 ) as carrier and sweep gas. TMA pulse time is 0.5s, H 2 The O pulse time is 0.8s, the precursor exposure time is 50s, the cleaning time is 60s, and the carrier gas flow rate is 10sccm. Heat the temperature of the reaction chamber to 70°C, keep the membrane at the set temperature of the reaction chamber for 20 minutes, and prepare modified membranes with 50, 100, 150, and 200 cycles respectively.

[0037] The surface-modified membranes in this example were observed and analyzed by scanning electron microscopy. The membrane pore size decreased with the increase of deposition times, and the hydrophilic angles changed from the original 131° to 125.1°, 120.2°, 63.5°, and 30.4° respectively. °, the tested pure water flux increased by 15.0%, 81.8%, 69.6%, and 57.6% respectively, and the rejection rate of monodisperse PS microspheres (average particl...

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Abstract

The invention relates to a method for performing surface modification on a polytetrafluoroethylene (PTFE) separation membrane, belongs to the field of membrane materials, and solves the problems of poor hydrophilicity, small flux, high probability of pollution and complex modification process existing in the polytetrafluoroethylene separation membrane. In the method, an oxide thin layer is continuously deposited on the surfaces of PTFE separation membrane pore paths by using an atomic layer deposition technology, so that precise adjustment and control over the aperture and the surface property of the separation membrane are realized. The method mainly comprises the following specific steps of: (1) controlling certain reaction temperature, and keeping the membrane into a reaction chamber for a period of time; (2) sequentially introducing trimethyl aluminum, titanium tetrachloride or titanium isopropoxide, cleaning gas and vapor or ozone and cleaning gas into the reaction chamber; and (3) preparing an organic/inorganic composite membrane with different cycle indexes according to requirements. By using the method, the hydrophilicity, the pure water flux and the anti-pollution capacity of the PTFE separation membrane are greatly improved; the method has a simple process; and the property is kept for a long time.

Description

technical field [0001] The invention relates to a separation membrane modification technology, in particular to a method for modifying the surface of a polytetrafluoroethylene separation membrane. Background technique [0002] PTFE has good chemical stability, heat resistance, sliding properties, wear resistance, corrosion resistance, self-lubricating properties, weather resistance, etc. It is a plastic with excellent comprehensive properties and has broad application prospects in the field of separation membranes . However, due to its low surface energy and poor hydrophilicity, there will be two problems when dealing with aqueous phase separation: one is strong hydrophobicity, which requires a large driving force for separation, high energy consumption, and low flux; It is easy to produce adsorption pollution, which makes the membrane flux smaller and the life span shorter. [0003] Researchers at home and abroad have done a lot of research on the surface modification of ...

Claims

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Application Information

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IPC IPC(8): B01D71/36B01D67/00
Inventor 汪勇许强
Owner NANJING UNIV OF TECH
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