Solidification of emulsified polymer solutions via phase inversion (SEPPI): A generic way to prepare polymers with controlled porosity

摘要

Porous polymeric structures with controlled porosity were prepared using a new approach involving solidification of emulsified polymer solutions via phase inversion (SEPPI). The new method starts from a polymeric emulsion for which the presence of nanosized particles or surfactants is crucial. Subsequent solidification of such emulsion is realized by simple contact with a polymer nonsolvent. The resulting solids exhibit spherical pores for which the emulsion droplets act as template. The preparation method allows easy control over pore morphology by tuning a number of easily accessible parameters, mainly at the level of the emulsion itself. A wide variety of polymers, including biocompatible and biodegradable polymers, can thus be turned into porous materials. Two typical applications in controlled release and solvent resistant nanofiltration are presented, illustrating the real practical utility of the presented method. Compared with the commonly used methods to prepare porous polymers, the presented method has a large potential since it (1) is applicable to a wide range of different polymers, (2) shows simply accessible flexibility in structural properties, such as porosity, pore size, pore interconnectivity, and pore wall functionality, (3) involves no chemical reaction in the polymer hardening process, and (4) allows creation of porous materials with an asymmetric structure.