Gradient crystallinity and its influence on the poly(vinylidene fluoride)/poly(methyl methacrylate) membrane‐derived by immersion precipitation method

Abstract

Herein, phase inversion poly(vinylidene fluoride)/poly(methyl methacrylate) (PVDF/PMMA) microporous membranes were prepared at various PMMA concentration by immersion precipitation method. Increment in the PMMA concentration has a significant influence in the PVDF membrane crystallinity, which is studied by differential scanning calorimeter, X-ray diffractometer, and smallangle X-ray scattering analyses. Properties such as membrane bulk structure, porosity, hydrophilicity, mechanical stability, and water flux vary in terms of PMMA concentration. Porosity is increased, and tensile strength decreased when PMMA concentration is beyond 30 wt %. Thermodynamic instability during the liquid to solid phase separation and variation in the crystallinity has an intense effect on these membrane properties. Then, 70/30 blend membrane selected as optimum composition owing to the high porosity and pure water flux compared to other compositions. This membrane is modified with a composite filler derived from the graphene oxide and titanate crosslinked by chitosan. The antibacterial, antifouling, and bovine serum albumin separation studies reveal that the developed nanocomposite membrane is a potential candidate for the separation application.Polymer blending is a facile strategy to design new materials with excellent properties without compromising the matrix polymer properties. In general, most of the polymer blends are immiscible and which leads to coarse morphology due to interfacial tension between the phases. 16 poly(methyl methacrylate) (PMMA) form the upper critical solution temperature (UCST) blend with PVDF polymer and phase separate upon cooling. Addition of this amorphous polymer changes the PVDF microstructure, which leads to the change in overall membrane properties. 17-20 PMMA found compatible with PVDF at its amorphous state. Aid et al. studied the thermodynamic miscibility of the PVDF in presence of Additional Supporting Information may be found in the online version of this article.

Evaluation of the Mechanical and Physical Properties of Maxillofacial Silicone Type A-2186 Impregnated with a Hybrid Chitosan–TiO2 Nanocomposite Subjected to Different Accelerated Aging Conditions

“…It is common for these polymer mixtures to be incompatible, resulting in a granular structure due to the stress between the combined phases. A study conducted by Remanan et al showed that, through the ultrasonic integration of a TiO 2 /chitosan/GO nanocomposite filler, the resulting membrane notably improved its defense against bacterial adherence and fouling [29].…”