SEPARATION OF WATER-ETHANOL MIXTURE BY PERVAPORATION THROUGH HYDROLYZED POLYACRYLONITRILE HOLLOW FIBER MEMBRANES

For the purpose of separating water-ethanol mixtures by the use of the pervaporation technique, new composite membranes composed of polyion complexes (PIC) as a separating layer were developed. The polyion complex structure, consisting of polyacrylic acid (PAA) and polycation, provided excellent permeation rate and selectivity. To obtain a composite hollow fiber membrane, a new technique was developed instead of coating. That is, the polyacrylonitrile membrane was partially hydrolyzed to introduce a carboxylic group, and then converted to a polyion complex. The alkaline hydrolysis reaction and the formation of the separating layer were analyzed by the use of IR, SEM, and EDX. In this manner, modules with effective membrane area up to 6m2 have been prepared.