A method for plasma modification of polytetrafluoroethylene microporous membrane

A polytetrafluoroethylene and plasma technology, applied in the direction of coating, can solve the problems of reduced mechanical strength of microporous membrane, maintaining PTFE microporous membrane, poor modification effect, etc., to improve hydrophilicity and short cycle. , the effect of excellent mechanical properties

Inactive Publication Date: 2019-04-16
NANJING UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In view of the existing hydrophilic modification method of polytetrafluoroethylene microporous membrane, the modification effect is not good, and the mechanical strength of the modified microporous membrane is reduced. The invention provides a polytetrafluoroethylene microporous The plasma modification method of the membrane uses the low-temperature plasma treatment method to modify the surface of the PTFE microporous membrane. By controlling the process parameters of the low-temperature plasma treatment, including the type of low-temperature plasma gas, treatment distance, radio frequency power, treatment time and gas Throughput, improve the hydrophilicity of PTFE microporous membrane, modify the original highly hydrophobic PTFE microporous membrane into a more hydrophilic PTFE microporous membrane, and the water contact angle is reduced from about 130° to about 40° , while maintaining the mechanical strength of the PTFE microporous membrane

Method used

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  • A method for plasma modification of polytetrafluoroethylene microporous membrane
  • A method for plasma modification of polytetrafluoroethylene microporous membrane
  • A method for plasma modification of polytetrafluoroethylene microporous membrane

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] Pretreatment of PTFE microporous membrane:

[0025] Flatten the PTFE microporous membrane with two A4 papers, place it under a flat paper cutter, and cut into several 5×5cm PTFE microporous membranes, and immerse the cut PTFE microporous membranes in acetone solution. Soak in a fume hood for 12-24h, then soak in 80%-98% ethanol solution for 3-12h, change the ethanol solution several times to remove acetone, then wash with deionized water several times to remove the ethanol, and finally put it in In a vacuum drying oven, dry at 30-70°C for 10-24 hours, cool the dried PTFE microporous membrane to room temperature, and then fix the microporous membrane on a glass plate for the next plasma modification.

Embodiment 2

[0027] The pretreatment method of the PTFE microporous membrane is as in Example 1.

[0028] Plasma treatment:

[0029] First put the pretreated PTFE microporous membrane in the plasma high vacuum preparation chamber, in the N 2 +CH 4 Under mixed gas, adjust the plasma treatment distance to 40cm, select the treatment time 100s, and the gas flow rate to 20cm 3 / s, the intake ratio is 1:1, that is, the gas flow rates of methane and nitrogen are both 10cm 3 / s, control the plasma power, the power is respectively selected 20w, 40w, 60w, 80w, 100w.

[0030] The plasma-treated PTFE microporous membrane was measured with a JY-82 contact angle meter (Chengde Testing Machine Factory), and the contact angle of water was measured at 6 different positions, and finally the average value was taken. The relationship between contact angle and plasma processing power is shown as figure 2 Shown. by figure 2 It can be known that the contact angle is between 40° and 60° at 20w to 100w. From the powe...

Embodiment 3

[0032] The pretreatment method of the PTFE microporous membrane is as in Example 1.

[0033] Plasma treatment:

[0034] Put the pretreated PTFE microporous membrane in the plasma high vacuum preparation chamber, 2 +CH 4 Under mixed gas, adjust the plasma treatment distance to 40cm and the gas flow rate to select 30cm 3 / s, the intake ratio is 1:1, that is, the gas flow rates of methane and nitrogen are both 10cm 3 / s, plasma processing power is 40w, control plasma processing time, the time is 20s, 40s, 60s, 80s, 100s.

[0035] figure 1 It is the contact angle diagram of the untreated PTFE microporous membrane (a) and the PTFE microporous membrane (b) after plasma treatment. The relationship between contact angle and plasma treatment time is shown in image 3 Shown. From figure 1 It can be seen that the contact angle of the PTFE film before plasma treatment is 130°, and the contact angle after the final treatment reaches 40°. From image 3 It can be seen that before 20s, as the trea...

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Abstract

The invention discloses a plasma modification method for a polytetrafluoroethylene microporous membrane. A low temperature plasma treatment method is adopted for conducting surface modification on the PTFE microporous membrane, process parameters of low-temperature plasma treatment, such as the low-temperature plasma gas type, the treatment distance, the radio-frequency power, the treatment time and the gas circulation volume, are controlled, hydrophilia of the PTFE microporous membrane is improved, the PTFE microporous membrane which is originally quite great in hydrophobicity is modified into the PTFE microporous membrane which is quite great in hydrophilia, the water contact angle is lowered to approximately 40 degrees from the original approximately 13 degrees, and meanwhile mechanical strength of the PTFE microporous membrane is maintained. The plasma modification method is short in cycle and low in cost, commercialized production can be conducted, and the application scope of the PTFE microporous membrane is further expanded.

Description

Technical field [0001] The invention belongs to the field of proton exchange membrane materials for fuel cells, and in particular relates to a plasma modification method of a polytetrafluoroethylene microporous membrane. Background technique [0002] Polytetrafluoroethylene (PTFE) is polymerized by tetrafluoroethylene. It only contains CC bond and CF chemical bond. Both chemical bonds contain very high chemical bond energy. Therefore, PTFE is chemically stable and can be used as an anticorrosive material. , The degradation rate is very small, the service life is relatively long, and it is widely used in medical application materials, anion exchange membranes, sealing materials, filter materials and other fields. [0003] Polytetrafluoroethylene microporous membrane has strong hydrophobicity, low surface energy, weak adhesion and wettability, which limits its application, so it needs to be modified for hydrophilicity. [Materials Research Bulletin, 2009,44(6):1437-1440] CeO is used ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08J9/40C08J9/36C08L27/18
CPCC08J9/36C08J9/40C08J2327/18
Inventor 杨加志夏庆成毛霏韩静刘晓慧曾干敏孙东平
Owner NANJING UNIV OF SCI & TECH
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