(The) transport phemomena of low aliphatic alcohols and urea through the copolymer hydrogel membranes

Abstract

A series of crosslinked 2-hydroxyethyl methacrylate (HEMA)-2,3-dihydroxypropyl methacrylate (DMPMA) copolymer membrances for transport experiments has been prepared. The cross-linker used was tetraethyleneglycol dimethacrylate(TEGDMA). Membranes were prepared by polymerizing the monomers as a thin homogeneous film. Using these membranes, relative permeabilities ($U_{re}$) and distribution coefficients ($K_D$) for low aliphatic alcohols and urea were measured. Also diffusion coefficients ($D_m$) and overall fractional coefficients (f) were calculated. In addition, equilibrium water content was measured. On the basis of hydrophilic interaction, the structural factors of solutes and above experimental data, the transport phenomena of the solutes through the copolymer hydrogel membranes were discussed. The results showed that urea has good permselectivity over the other solutes at the two compositions of 4(DHPMA): 6(HEMA) and 2(DHPMA): 8(HEMA). And it was revealed that the effect of hydrogen-bonding on diffusion gets more important with decreasing equilibrium water content in polymer matrix.