Formation of epoxy skin layers on the surface of supported Liquid membranes containing polyamines

Supported liquid membranes containing polyamine extractants have been stabi lized with semi-permeable epoxy skin layers. Liquid-vapor interfacial polym erization reactions were employed to deposit the epoxy layers. Different mo nomers were explored to investigate their effect on the integrity, morpholo gy, and chemical inertness of the resulting epoxy layers. Smooth, dense epo xy layers were formed on membranes containing undiluted 2-butyl-2-ethyl-1,5 -pentanediamine, or 4-(aminomethyl)-1,8-octanediamine, by polymerization wi th 1,3-butadiene diepoxide vapor. Both amines yielded skin layers that are more resistant to strong acids than polyamide skin layers. The 4-(aminometh yl)-1,8-octanediamine yielded a crosslinked epoxy skin layer that could wit hstand exposure to acetic acid. The resulting stabilized membranes transpor ted acetic acid at a flux of ca. 100 mu mol/m(2) s. (C) 1999 Elsevier Scien ce B.V. All rights reserved.