@article{scholars10679, publisher = {Hindawi Limited}, journal = {International Journal of Polymer Science}, title = {Exploiting the interplay between liquid-liquid demixing and crystallization of the PVDF membrane for membrane distillation}, volume = {2018}, note = {cited By 15}, year = {2018}, doi = {10.1155/2018/1525014}, abstract = {Membrane distillation (MD) purifies water by transporting its vapor through a hydrophobic membrane. An ideal MD membrane poses high water flux and high fouling, scaling, and wetting resistances. In this study, we develop polyvinylidene fluoride (PVDF) membranes for MD by focusing on reduction of PVDF degree of crystallinity. We explore the roles of dope solution temperature in dictating the phase separation mechanisms as well as the structure and the performance of semicrystalline PVDF membranes. DSC spectra show that higher dope solution temperature depresses crystallinity via formation of imperfect crystal. Such findings were also supported by FTIR and XRD results. The SEM images reveal formation of spherulite-like morphology in the membrane matrices for membranes prepared from high temperature dope solutions. A good balance between solid-liquid and liquid-liquid phase separations that offers low degree of crystallinity was found at a dope solution temperature of 60{\^A}oC (PVDF-60), which showed the MD flux of 18 l/m2 h (vs. 6 l/m2 h for temperature of 25{\^A}oC, as a benchmark) and nearly complete salt rejection when run at hot and cold temperatures of 65{\^A}oC and 25{\^A}oC, respectively. The PVDF-60 shows a high wetting resistance and stable MD flux of 10.5 l/m2 h over a 50 h test for treating brine solution as the feed (70 g NaCl/l). Copyright {\^A}{\copyright} 2018 N. I. M. Nawi et al.}, keywords = {Crystallinity; Distillation; Distilleries; Fluorine compounds; Fourier transform infrared spectroscopy; Liquids; Phase separation; Sodium chloride; Wetting, Cold temperatures; Degree of crystallinity; Hydrophobic membrane; Imperfect crystals; Liquid-liquid phase separation; Membrane distillation; Phase separation mechanism; Polyvinylidene fluoride membranes, Membranes}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85062608423&doi=10.1155\%2f2018\%2f1525014&partnerID=40&md5=8e8beba5a45436d445882c7feb6da287}, issn = {16879422}, author = {Nawi, N. I. M. and Bilad, M. R. and Nordin, N. A. H. M. and Mavukkandy, M. O. and Putra, Z. A. and Wirzal, M. D. H. and Jaafar, J. and Khan, A. L.} }