Superwettable PVDF/PVDF-g-PEGMA Ultrafiltration Membranes

Abstract

Poly(vinylidene fluoride) (PVDF) is a common and inexpensive polymeric material used for membrane fabrication, but the inherent hydrophobicity of this polymer induces severe membranes fouling, which limits its applications and further developments. Herein, we prepared superwettable PVDF membranes by selecting suitable polymer concentration and blending with PVDF- graft -poly(ethylene glycol) methyl ether methacrylate (PVDF- g -PEGMA). This fascinating interfacial phenomenon causes the contact angle of water droplets to drop from the initial value of over 70° to virtually 0° in 0.5 s for the best fabricated membrane. The wetting properties of the membranes were studied by calculating the surface free energy by surface thermodynamic analysis, by evaluating the peak height ratio from Raman spectra, and other surface characterization methods. The superwettability phenomenon is the result of the synergetic effects of high surface free energy, the Wenzel model of wetting, and the crystalline phase of PVDF. Besides superwettability, the PVDF/PVDF- g -PEGMA membranes show great improvements in flux performance, sodium alginate (SA) rejection, and flux recovery upon fouling.

Interpenetrating network nanoarchitectonics of antifouling poly(vinylidene fluoride) membranes for oil–water separation

“…During the phase separation process, the C–F points inward due to the hydrophobicity, and this condition greatly improves the hydrophilicity of the membrane surface. 28 This phenomenon once again verifies the changing trend of α and β crystal phases in ATR-FTIR spectra characterization, and the increase in hydrophilicity of the membrane surface is also proven in subsequent experiments.…”

“…4c depicts the two most common and stable conformations of PVDF: all- trans chain conformation (β-phase) and trans – gauche chain conformation (α-phase). 28 The β-phase molecules are arranged in an all- trans chain conformation, and the dipoles point in the same direction and are highly polar. 29 The dipoles in the α-phase are arranged in a way of internal compensation attributed to the accumulation of antiparallel chains and are generally non-polar.…”

Deaggregation and Crystallization Inhibition by Small Amount of Polymer Addition for a Co-Amorphous Curcumin-Magnolol System

“…Furthermore, the surface free energy was calculated from the contact angle data by van Oss’s acid-base method [ 38 , 39 ]. Taking into account the obtained values of the contact angle of standard test liquids ( Table S5 ) [ 38 , 56 ], the surface free energy of CUR-MAG CM was 38.6 mN/m and the polymer addition (MCC, VA64, and S630) showed a similar or slightly increased surface free energy. In contrast, CUR-MAG-HPMC CM, CUR-MAG-HPC CM, and CUR-MAG-PVP K30 CM exhibited higher surface free energy (64.4, 67.7, and 73.5 mN/m, respectively) ( Figure 9 ).…”

Modeling and Simulation of Polymerization Processes

“…[196] Superwettable PVDF/PVDF-g-PEGMA ultrafiltration membranes. [197] Removal of malachite green using carboxymethyl cellulose-g-polyacrylamide/montmorillonite nanocomposite hydrogel. [198] Ultraviolet illumination responsivity of the Au/n-Si diodes with and without poly (linolenic acid)-g-poly (caprolactone)-g-poly (t-butyl acrylate) interfacial layer.…”