2.3.1. HPAN membrane preparation
The PAN membranes were hydrolyzed
by immersing them in a 1
M
NaOH solution for 2 h followed by immersing them in a 1 M HCl solution
for 12 h to acidify PAN. During the acidification process, the sodium
carboxylate groups transformed into carboxylic acid groups. The
hydrolyzed and acidified PAN membranes will be henceforth
denoted as HPAN membranes.
Subsequently, the prepared HPAN membranes were thoroughly washed with DI
water.