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Abstract
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Novel biodegradable nanocomposite membranes were prepared by incorporating
diferent concentrations (2, 4 and 6 wt%) of graphene oxide (GO) as a nanoadditive
into a blend of sodium alginate/poly(ε-caprolactone) at ratio of 3:1 (SA:PCL) on the
basis of solution-casting method and were then used for dehydration of a series of
alcohols (methanol, ethanol and isopropanol) through pervaporation. The efects of
feed composition, GO content and various alcohols on pervaporation performance
were investigated. In addition, the swelling behaviors of SA/PCL/GO nanocomposite membranes were measured. All membranes were water selective, and the permeation rate increased with raising the GO content. The presence of GO having the
functional groups increased the hydrophilicity of the SA/PCL blend polymer matrix,
which resulted in the formation of a higher fux to water molecules. The best separation performance was achieved for the SA/PCL/GO-6 nanocomposite membrane
containing 6 wt% GO with isopropanol–water feed at 30 °C. An enhancement in
water concentration from 20 to 80 wt% increased the fux values from 506 to 779 g/
m2 h. Likewise, an increase in feed water composition in the case of ethanol–water
and methanol–water mixtures increased the fux values from 461 to 757 g/m2 h and
from 298 to 569 g/m2 h, respectively. However, the separation factor of water for all
membranes decreased with the increase in feed concentration. Pervaporation dehydration of aqueous isopropanol mixtures also proceeded easier than that of aqueous
ethanol and methanol mixtures due to the larger molecular size of isopropanol. High
dehydration performance of alcohol–water mixtures demonstrated the utility of
these membranes for use in solvent dehydration application with higher efciency.
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