Preparation and characterization of PES/CA microporous membranes via reverse thermally induced phase separation process

Abstract

The blend polyethersulfone (PES)/cellulose acetate (CA) flat‐sheet microporous membranes were prepared by reverse thermally induced phase separation (RTIPS) process. The effects of CA content and coagulation bath temperature on membrane structures and properties were investigated in terms of membrane morphology, water contact angle, permeation performance, and mechanical properties. The cloud point results indicated that the cloud point decreased with the increasing content of CA. When the coagulation bath temperature was lower than the cloud point, the membrane formation process underwent nonsolvent induced phase separation (NIPS) process and dense skin layer and finger‐like structure were formed in membranes. These membranes had lower pure water flux and poor mechanical properties. But when the coagulation bath temperature was higher than the cloud point, the membrane formation process underwent RTIPS process. The porous top surface as well as porous cross‐section of the membranes were formed. Therefore, high pure water flux and good mechanical properties were obtained. The contact angles results indicated that the hydrophilicity of the prepared membranes improved obviously with the addition of CA. When the content of CA was 0.5 wt% and the membrane formation temperature was 323K, the PES/CA microporous membrane which was prepared via the RTIPS process displayed a optimal permeability of the pure water flux of 816 L m−2 h−1 and the BSA rejection rate of 49.5%, which showed an increase of 48.9% and 23.6% than that of pure PES membrane, respectively. Moreover, the mechanical strengths of the membranes obtained by RTIPS process were better than those membranes prepared by NIPS process. POLYM. ENG. SCI., 58:180–191, 2018. © 2017 Society of Plastics Engineers

A new perspective and comparative study on demixing and gelation behavior of cellulose acetate, cellulose acetate propionate and cellulose acetate butyrate ternary solutions

“…As it can be seen in Figs. and , all the investigated ternary systems show small miscible region (small area of region I) and thus gelation is the main mechanism for preparation of membranes and thus it is expected to form a relatively porous top layer that makes it appropriate for using in microfiltration and ultrafiltration processes . These results are completely in agreement with the SEM graphs presented in Figs.…”

Preparation of PVDF ultrafiltration membranes using PVA as pore surface hydrophilic modification agent with improved antifouling performance

“…Table illustrated a comparison of our study results with other reported literatures on membrane performance. When compared with some published PVA modified membranes [21,32,40,42,54–56], the performances of our fabricated membranes were comparable or even better, the FRR, contact angle, antifouling property, and BSA rejection of our membranes are more favorable than the reported ones. In General, the membranes made in PVA/water coagulation bath display significant performances in hydrophilicity and antifouling performance.…”

“…In light transmittance experiment, a self‐designed instrument was used as stated by Li and co‐workers . A light source of laser was placed above the coagulation bath which contained different content PVA aqueous solutions.…”

Effect of nonsolvent additives on PES ultrafiltration membrane pore structure

“…The pressure‐resistant property of UF membranes has become an important research direction for researchers. At present, researchers mainly focus on preparation of UF membranes by various materials of high performance, such as polyethersulfone (PES), polysulfone (PSf), polyacrylonitrile, poly(vinylidene fluoride) (PVDF), and ceramic . An and coworkers obtained a PSf membrane with fully sponge‐like structure showing high flux and good pressure‐resistant property by adding ethanol and PVP‐k90 mixed additives into the PSf/dimethylacetamide (DMAC) casting solution.…”