Study on the Preparation of Cellulose Acetate Separation Membrane and New Adjusting Method of Pore Size
Jianming Wang, Hongchen Song, Long‐Fei Ren, Md. Eman Talukder, Shunquan Chen, Jiahui Shao
Abstract
As a kind of eco-friendly (biodegradable) material and with a natural anti-fouling ability, cellulose acetate (CA) is more suitable for single-use membrane (especially in bioprocess). In this study, the method for preparing CA membrane by Vapor-assisted Nonsolvent Induced Phase Separation (VNIPS) was studied. The influences of ratio compositions (solid content, acetone/N,N-Dimethylacetamide ratio, glycerol/CA ratio) and membrane preparation conditions (evaporation time, evaporation temperature and humidity) on the microstructure and other properties were systematically evaluated. Results indicated that acetone/N,N-Dimethylacetamide ratio and glycerol/CA ratio had great influence on the cross-section structure of membranes. Additionally, the membrane with homogeneous sponge-like porous structure could be prepared stably within certain limits of ratios. Under the premise of keeping the content of other components fixed, the separation membrane with a full sponge pore structure can be obtained when the ratio of glycerol/CA is ≥2.5 or the acetone/solvent ratio is between 0.25 and 0.5. Evaporation time and temperature, humidity and other membrane preparation conditions mainly affected the surface morphology and the pore size. This kind of high-performance membrane with homogeneous sponge-like pore and controllable surface morphology could be potentially used for bioseparation processes.