The preparation of a water-selective membrane from the crosslinking of high molecular weight poly(vinyl alcohol) (PVA) with tartaric acid is reported. The resulting membrane was characterized by IR spectroscopy, swelling studies, differential scanning calorimetry, and contact angle testing, and was finally applied in the pervaporation. The performance of the membrane was evaluated in relation to the mixing ratio, changes in feed concentration, and changes in operating temperature. An optimum mixing ratio of 80:20 (wt %) of PVA to tartaric acid was determined, giving a flux range from 0.0072 to 0.095 kg/m 2 h and a separation factor of 41.5-707.6 at 40-60 C and 80-90 wt % aqueous acetic acid feed solution. From an Arrhenius type of relationship, it was determined that flux varies exponentially with temperature. The activation energy was calculated for the permeation of each of component of the mixture, with a higher activation energy being observed for acetic acid than for water. From the separation index, it could be concluded that the membrane has good selectivity toward water and exhibits better performance at higher acetic acid concentrations.
Blended membranes of hydrophilic polymers poly(vinyl alcohol) (PVA) and poly(vinyl amine) (PVAm) were prepared and crosslinked with glutaraldehyde. The prepared membranes were characterized using infrared (attenuated total reflection mode) spectroscopy, differential scanning calorimetry, X-ray diffractometry, and scanning electron microscopy measurements. Pervaporation performances of the membranes were evaluated for the separation of water-isopropanol (IPA) mixtures. As the PVAm content increased from PVAm0 to PVAm1.5, the flux through a 70 lm film increased from 0.023 to 0.10 kg/m 2 h at an IPA/water feed ratio of 85/15 at 30 8C. The driving force for permeation of water increased due to the temperature but it has no effect on IPA permeation. Activation energies for the permeation of IPA and water were calculated to be 17.11 and 12.46 kJ/mol, respectively. Controlling the thickness of the blend membrane could improve the permeation flux with only a marginal reduction in the separation factor. V C 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45572.
Ag-exchanged NaY zeolite (Ag-NaZ) particles were prepared by ion exchange and introduced to a polyvinyl alcohol (PVA) membrane cross-linked with polyacrylic acid (PAA) for the pervaporation dehydration of an isopropanol (IPA) aqueous mixture. The Ag-exchanged NaY zeolite particles were characterized by FE-SEM, EDS, BET, and XRD studies. The prepared Ag-NaZ-loaded PVA/PAA composite membrane was characterized by FE-SEM, XRD, a swelling study, and contact angle measurements. Pervaporation characteristics were investigated in terms of Ag-NaZ concentrations within PVA/PAA membranes using diverse feed solution conditions. The preferential sorption of IPA/water mixtures for Ag-NaZ-introduced membranes were also determined by calculating the apparent activation energies of IPA and water permeation, respectively. As a result, flux and selectivity increased with the Ag-NaZ concentration to 5 wt% in the membrane. Optimum pervaporation performance was observed in a 5 wt% Ag-NaZincorporated membrane with a flux equal to 0.084 kg m À2 h À1 and a separation factor of 2717.9 at 40 C from an 80 wt% IPA aqueous feed solution.
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