Electrospun fiber membranes from blends of PVDF with fouling-resistant zwitterionic copolymers

Poster Session: 

B

Presenter: 

Nelaka Govinna

Authors: 

Nelaka Govinna(1), Papatya Kaner(2), Davette Ceasar(1,3), Anita Dhungana(1,4), Cody Moers(1,5), Katherine Son(1,4), Ayse Asatekin(2), Peggy Cebe(1)

Author Affiliation: 

(1) Department of Physics and Astronomy, Center for Nanoscopic Physics, Tufts University, Medford, MA 02155, USA (2) Department of Chemical & Biological Engineering, Science and Technology Center, Tufts University, Medford, MA 02155, USA (3) Temple University, Philadelphia, PA 19122, USA (4) Rochester Institute of Technology, Rochester, NY 14623, USA (5) Gallaudet University, Washington, DC 20002, USA

Abstract: 

Non-woven super-hydrophobic fiber membranes have potential applications in oil-water separation and membrane distillation, but fouling negatively impacts both applications. Membranes were prepared from blends comprising poly(vinylidene fluoride), PVDF, and random zwitterionic copolymers of poly(methyl methacrylate), PMMA, with sulfobetaine methacrylate, SBMA, or with sulfobetaine-2-vinylpyridine, SB2VP. PVDF imparts mechanical strength to the membrane, while the copolymers enhance fouling resistance. Blend composition was varied by controlling the PVDF:copolymer ratio. Non-woven fiber membranes were obtained by electrospinning solutions of PVDF and the copolymers in a mixed solvent of N,N-dimethylacetamide and acetone. The PVDF crystal phases and crystallinities of the blends were studied using wide angle X-ray diffraction and differential scanning calorimetry. PVDF crystallized preferentially into its polar beta phase, though its degree of crystallinity was reduced with increased addition of the random copolymers. Thermogravimetry showed that the degradation temperatures varied systematically with blend composition. PVDF blends with either copolymer showed significant increase of fouling resistance. Membranes prepared from blends containing 10% P(MMA-ran-SB2VP) had the highest fouling resistance, with a five-fold decrease in protein adsorption on the surface, compared to homopolymer PVDF. They also exhibited higher pure water flux, and better oil removal in oil/water separation experiments.