Membrane technology has become an important separation technology over the past few decades and is a promising way to cope with problems such as environmental protection, water shortage and energy consumption. Fluoropolymers constitute a unique class of materials with a combination of interesting properties that has attracted significant attention from material researchers over the past few decades.1-2) Generally, these polymers have high thermal stability, improved chemical resistance, and lower surface tension because of the low polarizability and the strong electronegativity of the fluorine atom, its small van der Waals radius, and the strong C-F bond. Because of its combination of good properties and processability, poly(vinylidene fluoride), PVDF, has been widely used as a membrane material. However, there are still challenging issues, such as, the relationship between polymorph and mechanical strength and permeability of PVDF membranes. In particular, ?-phase PVDF has some specific properties such as polarity and higher mechanical strength compared with ?-phase. It would be interesting to study the effect of polymorphism on transport properties. The present work focused on the effect of the interactions between poly(vinylidene fluoride) (PVDF) chains and solvent molecules on the structure of PVDF in films obtained by solution casting. We performed molecular dynamics (MD) simulation to probe self-organization and structure of PVDF molecular chains and the relationship between polymorphism and water transport. The effect of additives has been verified. The theoretical results are used to better understand the relationship between PVDF crystalline forms and membrane preparation conditions. References 1) Z. Cui, E. Drioli, Y.M. Lee, Prog. Polym. Sci. 39(1) 164-198 (2013). 2) P. Martinsa, A.C. Lopesa, S. Lanceros-Mendeza Prog. Polym. Sci. 39 683-706 (2014)
Exploring Polymorphism in Poly(vinylidene fluoride): The influence of solvent
Tocci E;Drioli E
2016
Abstract
Membrane technology has become an important separation technology over the past few decades and is a promising way to cope with problems such as environmental protection, water shortage and energy consumption. Fluoropolymers constitute a unique class of materials with a combination of interesting properties that has attracted significant attention from material researchers over the past few decades.1-2) Generally, these polymers have high thermal stability, improved chemical resistance, and lower surface tension because of the low polarizability and the strong electronegativity of the fluorine atom, its small van der Waals radius, and the strong C-F bond. Because of its combination of good properties and processability, poly(vinylidene fluoride), PVDF, has been widely used as a membrane material. However, there are still challenging issues, such as, the relationship between polymorph and mechanical strength and permeability of PVDF membranes. In particular, ?-phase PVDF has some specific properties such as polarity and higher mechanical strength compared with ?-phase. It would be interesting to study the effect of polymorphism on transport properties. The present work focused on the effect of the interactions between poly(vinylidene fluoride) (PVDF) chains and solvent molecules on the structure of PVDF in films obtained by solution casting. We performed molecular dynamics (MD) simulation to probe self-organization and structure of PVDF molecular chains and the relationship between polymorphism and water transport. The effect of additives has been verified. The theoretical results are used to better understand the relationship between PVDF crystalline forms and membrane preparation conditions. References 1) Z. Cui, E. Drioli, Y.M. Lee, Prog. Polym. Sci. 39(1) 164-198 (2013). 2) P. Martinsa, A.C. Lopesa, S. Lanceros-Mendeza Prog. Polym. Sci. 39 683-706 (2014)I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
