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tao851002

银虫 (小有名气)

[求助] 聚合物电解质PVDF/PMMA共混膜的制备

本人刚开始做聚合物电解质膜,参照一篇文献做聚合物电解质PVDF/PMMA共混膜,
但是做出来的膜很脆,我是按文献中取10mlDMF+1ml甘油,100ml烧杯中磁力搅拌先使两种溶剂混合均匀,再称取15wt%(占混合溶剂质量比)PVDF+PMMA(两者质量比5:5),加入烧杯中,80度磁力搅拌3h,使聚合物溶解到溶剂中,第一次做时发现搅了一个半小时后,DMF挥发了很多,最后溶液变得粘度很大的那种,第二次做时,我在烧杯上用保鲜膜包住了烧杯口,这样DMF不会跑掉了,搅了3个小时后,在玻璃板上刷膜,然后在真空烘箱中120度下放了24h,但得到的膜很脆,很容易烂掉。溶解聚合物时的过程不太明白,到底是否这个过程中溶剂挥发些,或者是应该让溶剂挥发些以得到特定粘度的浆液呢? 请高手们指导下,谢谢!
下面是文献中实验部分的内容:
The polymer blend membranes were prepared by the phase-separation method. Poly(vinylidene fluoride) (PVDF,Mw = 534,000, Sigma–Aldrich) and poly(methyl methacrylate)(PMMA, Mw = 350,000, Sigma–Aldrich) were dried for 24 h at
100 ◦C in vacuum. The required amounts of PVDF and PMMA were dissolved in a mixture of N,N-dimethyl formamide (DMF, >99.8%,Sigma–Aldrich) and glycerin (Fluka) (10:1 by volume), and stirred for 3 h at 80 ◦C. Then, the solution was cast onto a glass plate and dried at 120 ◦C for 24 h in vacuum. During this process, DMF and glycerin evaporated in turn, and the voids left by the glycerin
formed micropores. The polymer electrolytes were obtained by soaking the obtained membranes in 1 M LiPF6 in a mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC; 1:1 by volume, MERCK, Germany). The compositions of the PVDF/PMMA membranes and the corresponding polymer electrolytes that were prepared are listed in Table 1. M0, M30, M50. M70, M90, and M100
designate the membranes with PVDF to PMMA (wt.%:wt.%) weight ratios of 100:0, 70:30, 50:50, 30:70, 10:90, and 0:100, respectively.The corresponding polymer electrolytes are designated as E0, E30,E50, E70, E90, and E100, respectively.
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HVK
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tao851002

银虫 (小有名气)

引用回帖:
5楼: Originally posted by 501258123 at 2012-09-21 09:20:39
不让挥发,最好密封的瓶子。...

不让挥发,搅几个小时后发现浆液有点稀,粘度很小似的,是不是说明加的聚合物浓度太低了,是不是应该用有一定粘度的浆液刷膜,谢谢!!
HVK
6楼2012-09-21 11:00:25
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tao851002

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没人回答,自己先顶下
HVK
2楼2012-09-20 11:01:55
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501258123

至尊木虫 (正式写手)

中级狗狗

【答案】应助回帖

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感谢参与,应助指数 +1
seagrove: 金币+2, 感谢应助交流 2012-09-21 11:12:58
PMMA成的膜就是很脆。建议你在玻璃板上刮好膜之后,可以在温度低一点的烘箱中(60℃左右)烘干,不要烘得很干揭膜,揭下来后再120℃真空烘干。
天上掉下个大金蛋~
3楼2012-09-20 16:45:01
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tao851002

银虫 (小有名气)

引用回帖:
3楼: Originally posted by 501258123 at 2012-09-20 16:45:01
PMMA成的膜就是很脆。建议你在玻璃板上刮好膜之后,可以在温度低一点的烘箱中(60℃左右)烘干,不要烘得很干揭膜,揭下来后再120℃真空烘干。

哦 ,那我试下看,先在低温下烘,
我问下那在制作浆液时,让不让溶剂挥发呢?谢谢!
HVK
4楼2012-09-20 21:29:10
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