PVDF Membrane Morphology - Influence of Polymer Molecular Weight and Preparation Temperature

Abstract

The global polyvinyldene flouride market is estimated to reach $937,278.5 thousand by 2019, therefore to develop new membranes and gain pioneering ideas, which could create innovative business opportunities, a fundamental knowledge about membrane properties fabricated from recent commercially available PVDF polymers is highly mandatory. In this study, we successfully prepared nine non-woven supported PVDF membranes using a phase inversion precipitation method starting from a 15 wt% PVDF solution in N-methyl-2-pyrrolidone. Various membrane morphologies were obtained by using (1) PVDF polymers with diverse molecular weight in a range from 300.000 Da to 700.000 Da and (2) different temperatures of the coagulation bath (20, 40, and 60 ±2°C) used for the films precipitation. Environmental Scanning Electron Microscope (ESEM) was used for surface and cross-section morphologies characterization.  Atomic Force Microscope (AFM) was employed to investigate surface roughness, while Contact Angle (CA) instrument was used for membranes wettability studies. Fourier Transform Infrared Spectroscopy (FTIR) results show that the fabricated membranes are formed by a mixture of TGTG’ chains in α phase crystalline domains and all-TTTT trans planar zigzag chains characteristic to β phase. Moreover, generated results indicate that the phases content and membrane morphologies depend on the polymer molecular weight and conditions used for the membranes preparation. The diversity of fabricated membranes could be applied by the End User Industries for different applications.

Dimethyl Isosorbide As a Green Solvent for Sustainable Ultrafiltration and Microfiltration Membrane Preparation

“…60 In the case of membranes prepared by VIPS-NIPS (PVDF6010−2.5 M and PVDF6010−5M), the decrease of polymer molecular weight, from a kinetic point of view, increased the solvent/nonsolvent exchange fostering the formation of a more porous sponge-like structure (as confirmed by pore size measurements). 61 On the contrary, for the membrane prepared just by NIPS techniques (PVDF6010−0M), a totally dense morphology was obtained.…”

Solution Blow Spinning of Polyvinylidene Fluoride Based Fibers for Energy Harvesting Applications: A Review

“…It has been shows that polymers with high molecular weights are more suitable for fiber spinning [ 71 ] and a higher molecular weight of precursor PVDF yield nanofibers with bigger diameters [ 72 ]. The molecular weight of precursor PVDF also affects the fraction of β-phase in the produced nanofibers [ 73 ]. When polymer has high molecular weight, the formation of bundles of fibrils is easy in the cross-linked polymer fiber [ 74 , 75 ].…”

The Effect of Temperature and Exposure Time on Stability of Cholesterol and Squalene in Latent Fingermarks Deposited on PVDF Membrane

“…Even though this membrane is not frequently encountered in real‐life casework, polyvinylidene difluoride (PVDF) membrane is one of the most widely studied and used polymer. It is usually used in Western blotting and protein sequencing applications due to its unique features including high binding capacity, high mechanical strength, hydrophobic nature, and excellent chemical and thermal resistance . Here, the use of PVDF membrane was to model test the temperature stability of fingermark components, such as cholesterol and squalene.…”