Abstract

Preparation of a porous support for a thin-film composite (TFC) membrane was achieved based on a highly aromatic poly(hydroxyamide) (PHA) formed from 5-hydroxyisophthalic acid and 4,4 '-(hexafluoroisopropylidene)dianiline. PHA synthesis was confirmed by Fourier transform infrared and proton nuclear magnetic resonance (H-1 NMR) spectroscopies. PHA was soluble in N-methyl-2-pyrrolidinone (NMP), N,N-dimethylacetamide (DMAc), and tetrahydrofuran (THF) with Mw 6.1x10(4) Da. Moreover, PHA showed good thermal stability up to 390 degrees C. Parameters for an appropriated PHA porous structure support membrane by the phase-inversion method were determined. Porous PHA support offers higher thermal stability and better adhesion between support amide thin skin layer than the ones used actually. Water permeation flux was 543Lm(-2)h(-1) for PHA porous support, whereas thin-film composite membrane PHA-TFC formed presented a decrease in water permeation flux (2.5Lm(-2)h(-1)) and a salt rejection capacity of 29% which situates it as a nanofiltration membrane.