Tailoring the properties of asymmetric cellulose acetate membranes by gas plasma etching

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:245

Article

Riekerink, MBO ; Engbers, GHM ; Wessling, M ; Feijen, J

关键词: membranes;    cellulose acetate;    gas plasma treatment;    etching;    surface modification;    surface analysis;    wettability;    permeability;    selectivity;    fouling;   

DOI  :  10.1006/jcis.2001.8029

来源: Elsevier

【 摘 要 】

Cellulose triacetate (CTA) ultrafilters and cellulose acetate blend (CAB) desalination membranes were treated with a radiofrequency gas plasma (tetrafluoromethane (CF4) or carbon dioxide (CO2), 47-49 W 0.04-0.08 mbar). Treatment times were varied between 15 s and 120 min. The plasma-treated top layer of the membranes was characterized by scanning electron microscopy, X-ray photo-electron spectroscopy, and contact angle measurements to obtain information about surface structure, chemistry, and wettability, respectively. The membrane properties (e.g., permeability, selectivity, fouling) were studied by waterflux measurements, molecular weight cutoff measurements, and fouling experiments with bovine serum albumin. CO2 plasma treatment resulted in gradual etching of the membrane's dense top layer. Permeation and selectivity changed significantly for treatment times of 0-15 min for CTA and 5-60 min for CAB membranes. Moreover, CTA membranes were hydrophilized during CO2 plasma treatment whereas CF4 plasma treatment led to hydrophobic surfaces due to strong fluorination of the top layer. This study shows that gas plasma etching can tailor the properties of asymmetric cellulose acetate membranes by simultaneously modifying the chemistry and structure of the top layer. The low fouling properties of CTA membranes were thereby largely maintained. (C) 2002 Elsevier Science.

【 授权许可】

Free