Preparation and evaluation of poly(vinylidene fluoride)-sulfonated poly(1,4-phenylene sulfide) based membranes with improved hydrophilicity

Abstract

Poly(vinylidene fluoride) (PVDF) based water purification membranes exhibit excellent thermal stability and chemical resistance, but also possess inherent drawbacks such as severe membrane fouling, lower separation efficiency and water flux due to its hydrophobic nature. In the present study, we attempted to enhance the hydrophilicity of PVDF membranes by treating with varying content (0 to 3 wt%) of partially sulfonated poly(1,4-phenylene sulfide) (sPPS) component using phase-inversion process. Compared to neat PVDF membrane, the PVDF/sPPS blend membranes exhibited typical asymmetric morphology with larger finger-like pores, efficient distribution of hydrophilic SO 3 -groups and decreasing water contact angle (WCA) upto 62 o (77 o for neat PVDF) as confirmed from scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX) and contact-angle measurements, respectively. Studies carried out for pure water flux (880 L/m 2 h) and blood serum albumin (BSA) solution flux (185 L/m 2 h) confirmed the enhanced permeability and higher fouling resistance for PVDF-sPPS (3 wt% sPPS) membranes compared to neat PVDF membrane (175 L/m 2 h and 63 L/m 2 h, respectively), though the BSA flux decreased with an increase in the filtration time due to membrane fouling. Compared to the total organic carbon (TOC) values of poly(ethylene oxide) (PEO) aqueous solutions before permeation (189.9 mg/L for M w =100,000 and 75.68 mg/L for M w =300,000), TOC of neat PVDF membrane decreased to 15 mg/L for M w = 100,000 and 5 mg/L for M w =300,000. With increasing sPPS content, the TOC values showed an increasing trend due to their increasing pore size. Overall, the incorporation of sPPS in PVDF membrane lowered the WCA, enhanced fouling resistance and improved its permeability and selectivity, which exemplifies the importance of this study.

PbS Nanoparticles Dispersed in Acid–Base Pair Polymer Nanocomposite Foams for High-Temperature Polymer Electrolyte Membrane Fuel Cell Applications

“…In the EDX experiment of PbS NPs (Figure S7g), the existence of the constituents’ only lead (Pb) and sulfur (S) is demonstrated, and the results affirm the formation of PbS NPs with good crystallinity. The microstructure of bare PA-APAAEs membranes affects their macro properties such as the WU, SR, contact angle, and PC. , The obtained SEM images are presented in Figure S7c,d and these images illustrate that the bare PA-APAAEs polymer has a compact and spherical surface. Moreover, the EDX experiment of the virgin PA-APAAEs membrane (Figure S7h) indicates the presence of solely phosphorous (P), carbon (C), nitrogen (N), and oxygen (O), as constituents, which confirms the formation of an unmodified APAAEs polymer and its surface successfully doping the PA. With the addition of PA and PbS NPs, the porosity of the APAAEs membrane decreased (indicating an enhanced smooth surface), as did the microphase partition between hydrophilic (indicated by dark regions) and hydrophobic domains (shown through bright patches) .…”

Piezoelectric sensor based on electrospun poly(vinylidene fluoride)/sulfonated poly(1,4‐phenylene sulfide) blend nonwoven fiber mat

“…Partially sulfonated poly(1,4‐phenylene sulfide) (sPPS) with the degree of sulfonation of sPPS ca. 0.177 was prepared through sulfonation of PPS fabric as reported in our previous work 27 …”

“…[28][29][30] In our study, the peak at 1404 cm À1 was used to normalize the spectral samples to negate the possible thickness differences among the many samples used, as this peak does not overlap with characteristic peaks of sPPS and all different crystal modifications of PVDF have the same peak. 12,27 Even a small amount of sPPS (10 wt%) added to PVDF increased the intensity of β-crystalline peak (1276 cm À1 ) significantly along with relative decrease in α-crystalline phase (764 cm À1 ) of PVDF (Figure 1c). Fraction of β-phase (F(β)) in PVDF 26 as a function of sPPS concentration is shown in Figure 1d.…”

Fabrication of CuO-NP-Doped PVDF Composites Based Electrospun Triboelectric Nanogenerators for Wearable and Biomedical Applications

“…Ferroelectric PVDF materials have attracted much attention due to their advantages, such as a high residual polarization, light weight, good mechanical properties, and high break-down voltage [41,42]. Semi-crystalline PVDF has five distinct crystalline phases (α, β, γ, δ, and ε) [43,44].…”