Preparation and Characterization of Matrix Hybrid Membranes Polyvinylidene Fluoride/Polyvinylpyrrolidone/Silica Gel/Zinc Oxide for Cr(VI) Removal from Water

Abstract

Matrix hybrid membranes, based on polyvinylidene fluoride (PVDF), poly (N-vinylpyrrolidone) (PVP), silica gel (SG) and zinc oxide (ZnO) were synthesized by phase inversion via immersion precipitation method. The characterization of membrane samples was performed using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), optical microscopy, contact angle, porosity, mean pore size and water permeability measurements. The FTIR analysis showed the appearance of new bands attributed to the functional groups of SG and ZnO. The XRD analysis confirmed a modification in the structure of membranes. The prepared membranes were used for the removal of hexavalent chromium (Cr(VI)) from aqueous solution. Membrane filtration experiments show that the water permeability and Cr(VI) rejection ratios increase with increasing the weight ratio ZnO (%)/SG (%). The maximum values of the Cr(VI) rejection rate and water permeability were respectively 85% and 685 L/m2hbar for weight ratios (0.75% of ZnO/0.25% of SG).

Influence of Sodium Maghnite Nanoclay on the Polyvinylidene Fluoride Crystal Transition in Composite Membranes and Its Effect on Bovine Serum Albumin Protein Extraction

“…The composition of the synthetic solutions based on PVDF, PVP, Sodium maghnite and DMF is shown in Table 3, the components was mixed at 8 h with temperature of 50℃, one uses the method of precipitation by phase inversion [1]. 2.5 Characterization of membranes 2.5.1 Fourier transformed infrared spectroscopy (FTIR) of the membrane samples After drying the samples of each membrane at a temperature of 50℃.…”

“…It was found that the peaks located at 10°,17° and 20° belongs to (001), (110) symmetrical planes respectively. The XRD data collected from Table 1 show that these planes reflect the positions of the atoms corresponding to α crystal conformation of the PVDF in M1 membrane [1]. The peak located at 20.26° is assigned to the planes (022) of βcrystal phase of PVDF (Table 1).…”

“…The surface of synthetised membrane samples was observed using optical microscope with resolution 40X referring to the method established previously [1].…”

“…The water rejection rate of BSA and fouling index for each membrane was measured using pilot unit (Amicon 8200), with cell surface area is 29 cm 2 used in the experimental test by Chabane et al [1]. BSA rejection rates was calculated using the following equation:…”

“…Polyvinylidene fluoride (PVDF) is semi crystalline polymer which can be used in free or combined states for the manufacture of different materials such as sensors and porous membranes applied for ultrafiltration and microfiltration separation technology [1]. The selective choice of PVDF as favorable macromolecule for industrial applications is mainly due to his attractive properties such as the mechanical strength, chemical stability, thermal resistance and electrical conductivity.…”