Solid phase extraction membranes with submicron multifunctional adsorbent particles

Abstract

Asymmetric polyethersulfone membranes with submicron particles comprising crosslinked poly(glycidyl methacrylate-co-2-acrylamido-2-methylpropane sulfonic acid) were prepared by a combination of a traditional liquid phase inversion process for making membranes with photopolymerization and crosslinking of functional monomers included in the casting solution. Scanning electron microscope images of the membrane cross-section revealed a hybrid structure with an interconnected network of submicron particles embedded within the porous polyethersulfone support. Permeation of toluidine blue solutions through non-functionalized membranes showed a dramatic effect of 2-acrylamido-2-methylpropane sulfonic acid concentration in the casting solution on the dynamic adsorption performance. The epoxide groups present in glycidyl methacrylate copolymer were transformed into amine functionalities by ring opening under alkaline conditions. Permeation of dilute Cu2+ solutions through functionalized membranes demonstrated that the plate height for some of these membranes was an order of magnitude smaller than for commercial particle-filled membranes used in solid phase extraction.