Nonsolvent pretreatment

Tin PS, Chung T-S, Hill AJ (2004) Advanced fabrication of carbon molecular sieve membranes by nonsolvent pretreatment of precursor polymers. Ind Eng Chem Res 43 (20) 6476-6483... 

The pretreatment was made by soaking the membrane (dense membrane) into liquid alcohols by Tin and co-workers [82], Dense membranes were prepared from two kinds of polyimide (PI), i.e. Matrimid 5218 (3,3 4,4 -benzophenone tetracar-boxilic dianhydride and 5(6)-amino-l-(4 -aminophenyl)-l,3-trimethylindane), and P84 (copolymer of 3,3, 4,4 -benzophenone tetracarboxylic anhydride and 80% methylphenylene-diamine+20% methylenediamine). The membranes were then immersed into nonsolvent for 1 day at room temperature, followed by drying naturally for 24 h. Then the membrane was subjeeted to the heating scheme given in Fig. 4.30 for carbonization. 

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