Porous Hollow Fibers with Controllable Structures Templated from High Internal Phase Emulsions

A technique to fabricate hollow fibers with porous walls via templating from high internal phase emulsions (HIPEs) has been demonstrated. This technique provides an environmentally friendly process alternative to conventional methods for hollow-fiber productions that typically use organic solvents. HIPEs containing acrylate monomers were extruded into an aqueous curing bath. Osmotic pressure effects, manipulated through differences in salt concentration between the curing bath and the aqueous phase within the HIPE were used to control the hollow structures of polyHIPE fibers. The technique was used to produce porous fibers (with millimeter-scale diameters and micronscale pores) having a hollow core (with a diameter of 50%-75% of the fiber diameter). Two potential applications of the hollow fibers were demonstrated. In vitro drug release studies using these hollow fibers show a controlled release profile that is consistent with the microstructure of the porous fiber wall. In addition, the presence of pores in the walls of polyHIPE fibers also enable size-selective loading and separation of functional materials from an external suspension.