Nonsolvent induced phase separation preparation of poly(vinylidene fluoride-co-chlorotrifluoroethylene) membranes with tailored morphology, piezoelectric phase content and mechanical properties. (25th December 2015)

• Record Type: Journal Article
• Authors: Cardoso, V.F.; Botelho, G.; Lanceros-Méndez, S.
• Is Part Of: Materials & design. Volume 88(2015:Dec.)
• Page Start: 390
• Page End: 397
• Publication Date: 2015-12-25
• Subjects: Poly(vinylidene fluoride-chlorotrifluoroethylene) – P(VDF-CTFE) -- Nonsolvent induced phase separation – NIPS -- Tailored microstructure -- Crystalline phases -- Mechanical properties; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2015.09.018
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: Poly(vinylidene fluoride- co -chlorotrifluoroethylene) – P(VDF-CTFE) membranes are increasingly interesting for a wide range of applications, including battery separators, filtration membranes and biomedical applications. This work reports on the morphology, hydrophobicity, thermal and mechanical properties variation of P(VDF-CTFE) membranes processed by nonsolvent induced phase separation (NIPS) technique as a function of the main processing parameters. All membranes show a porous structure composed of large spherulites, (interconnected) micropores and/or microvoids depending on the processing conditions used that in turn affect their hydrophobicity and mechanical properties. The degree of crystallinity of the membranes remains approximately constant with a value of about 15%, except for the membranes immediately immersed in ethanol, which is of about 23%. In turn, the crystalline phases present in the copolymer is mainly affected by the temperature and nonsolvent characteristics of the coagulation bath, the β-phase content ranging from 33 to 100%, depending on those processing parameters. It was show that the temperature of water-based coagulation bath plays an important role in order to produce structurally uniform and homogeneous porous membranes, which is particularly important from the point of view of technological applications. Graphical abstract: Highlights: P(VDF-CTFE) membranes have been processed by non-solvent induced phase separation. Morphology, wettability and mechanical properties depend on the processing conditions. Morphologies including large spherulites, micropores and/or microvoids were obtained. P(VDF-CTFE) membranes can be tailored by this technique for specific applications.