Characteristics, Performance of Blend CA/SPEEK Ultrafiltration Membranes Prepared by Phase Inversion Method using PEG 600 as an Additive

Abstract

Flat sheet asymmetric polymeric membranes is prepared by phase inversion method from homogeneous solution of 17.5 wt% cellulose acetate (CA) and sulfonated poly ether ether ketone (SPEEK) with polar solvent of N, N’– dimethylformamide (DMF). The different concentration of polyethylene glycol is used as the polymeric additives in the CA/SPEEK casting solution. The effects of polyethylene glycol 600 (PEG 600) concentration on the structure and performance of CA/SPEEK ultrafiltration membranes were investigated in more detail. The optimal preparation conditions were: 17.5 wt% total polymer composition, 65/35 wt% CA/SPEEK blend composition and 10 wt% PEG 600. The permeation performances of the membranes were evaluated in terms of pure water flux, equilibrium water content, hydraulic permeability, and solute rejection. The morphology and structure of the resulting membranes were observed by scanning electron microscope (SEM). CA/SPEEK membranes with higher concentration of 10 wt% PEG have higher PWF and equilibrium water content due to high porosity. With increase in PEG concentration from 0 to 10 wt%, the PWF increases from 129 to 259 lm–2h–1 in 65/35 wt% of CA/SPEEK as blend. When increasing concentration of PEG is substituted for SPEEK in proportion to form a homogeneous blend, the membrane hydraulic resistance reduces from 9.2 to 2.9 kPa/l.m–2.h–1for blend membranes with 0 to 10 wt % PEG 600 at 95/5 wt % CA/SPEEK composition. Solution of proteins of different molecular weight was used to study the permeation performance of prepared membranes using a batch membrane cell of 400 ml capacity.