Syntheses and characterization of blend membranes of sodium alginate and poly(vinyl alcohol) for the pervaporation separation of water + isopropanol mixtures

Abstract

ABSTRACT:The blend membranes of sodium alginate and poly(vinyl alcohol) have been prepared by physical mixing in different ratios (75, 50, and 25%) of sodium alginate with poly(vinyl alcohol). The membranes were crosslinked with glutaraldehyde and used in the pervaporation separation of water ϩ isopropanol mixtures at 30°C. The crosslinking reaction was confirmed by Fourier transform infrared spectra. Permeation flux increased with an increase in mass % of water in the feed mixture as well as with an increase in the amount of poly(vinyl alcohol) in the blend, but separation selectivity decreased. Diffusion coefficients of water ϩ isopropanol mixtures have been calculated using the Fick's equation from the sorption data. Arrhenius activation parameters were calculated for 10 mass % of water in the feed mixture using the values of flux and diffusion coefficients obtained at 30, 40, and 50°C. The diffusion and pervaporation results have been explained on the basis of solution-diffusion principles.

Modification of tetraethylorthosilicate crosslinked poly(vinyl alcohol) membrane using chitosan and its application to the pervaporation separation of water–isopropanol mixtures

“…Generally, with increasing density of the membrane either by increasing the crosslinking density or by incorporating the another polymer in the membrane matrix, the permeation flux decreases and selectivity increases. 38,39 However, in the present study, both the permeation flux and selectivity increased simultaneously with increasing chitosan content in the membrane. Although this is in contrast to the trade-off phenomenon existing between flux and selectivity in PV experiment, a significant enhancement of hydro- philicity and selective adsorption overcome the situation by the incorporation of chitosan in the membrane matrix.…”

Preparation and characterization of CMCS/PVA blend membranes and its sorption and pervaporation performance (I)

“…There are a number of research groups using GA to crosslink CS composite membranes for PV dehydration and their membranes performed very well. 39,40 In this study, GA was used as the crosslinking agent for the CMCS/PVA 8 : 2 blend membrane, sulfuric acid performed as catalyst, and PV dehydration of the crosslinked CMCS/PVA membrane was carried out for aqueous solutions with 95 wt % ethanol. It is shown in Figure 11.…”

In Separation and Purification

“…Similar Na − Alg membranes crosslinked with glutaraldehyde (GA) showed an improved performance toward the separation of ethanol/water by pervaporation [151] . The performance of GA crosslinked Na − Alg membrane was enhanced by blending it with different hydrophilic polymers like PVA [152,153] and cellulose [154] .…”