Insights into Superhydrophobicity and Fouling Effects of Novel PVDF-HFP Hollow Fiber Membranes
Paper ID : 1171-MST2015-FULL
Abolfazl Dastbaz1, Javad Karimi-Sabet *2
1Department of Chemical engineering, University of Tehran, Tehran, Iran
2NFCRS, Nuclear Science and Technology Research Institute, Tehran, Iran
In this Study, the newly developed hollow fiber membrane of polyvinylidine fluoride-hexafluoropropylene/Graphene Oxide (PVDF-HFP/GO) was fabricated by dry/wet jet spinning technique. The precursor of 12 wt% polymer solution in Normal Methyl Pyrrolidone (NMP), as solvent, were prepared and mixed by different amounts of GO powder. The composite membranes were then silanized using a low surface energy material, Octadesyltrichlorosilane (ODS). A variety of techniques such as FTIR, liquid entry pressure (LEP) measurement, contact angle (CA) goniometry and tensile test were applied to explore the effects of surface modification and GO content on the surface chemistry, structure and performance of the membranes. The prepared modified hollow fiber membrane exhibit a competitive permeation flux of 19.1 ± 1.2 kg m −2 h−1 in MD (feed and permeate temperate were set at 343 and 288 K, respectively). Furthermore, the LEP and water contact angle were increased from 105 ± 5 kPa and 115° ± 2 for pristine PVDF-HFP membrane to 123 ± 5 kPa and 160° ± 2 for modified PVDF-HFP/GO membrane, respectively. It was found that GO incorporation into the membrane matrix not only induce the hierarchy roughness on the membrane surface but also provides reactive hydroxyl sites for the hydrolyzed silane coupling agent to be anchored forming a robust uniform water repellent film. Also, Fouling effect was studied by performing DCMD experiment with salty water feed. Results exhibit that salt precipitation and permeation flux reduction did not occur during 24 h for both pristine and modified membranes.
PVDF-HFP, Octadecyltrichlorosilane, Superhydrophobicity, Membrane Distillation
Status : Paper Accepted (Oral Presentation)