Abstract
Membrane charge was evaluated of thirteen dialysis membranes i.e., regenerated cellulose, cellulose di-actetate, cellulose triacetate, hemophan, polyethylene-glycol-graft-edcellulose, ethylene vinylalcohol, polymethylmetacrylate, polyacrylonitrile(Asahi, AN69), polysulfone, polyester polymer alloy, and polyamide using 6 dyes, i. e., methylene blue and crystal violet (cationic dye), orange II and acid yellow 23 (anionic dye), Congo red and direct yellow 8 (direct dye). The negatively or positively charged dialysis membranes are stained with positively or negatively charged dyes, but these dialysis membranes are stained by other mechanisms. Therefore, use of charged dyes is insufficient to evaluate membrane charge.
