Design and characterization of nanoporous polymeric materials via reactive encapsulation of a chemically inert solvent

Nanoporous polymeric materials are used as polyelectrolytes in fuel cells, separation membranes, sensors and actuators, templates for nanoparticle synthesis, and electroactive material in biomedical applications. Design of nanoporous polymeric materials for such applications entails controlling permeability by tailoring the pore size and pore chemistry. A novel method of synthesizing nanoporous polymeric materials is employed in this work. This technique involves the synthesis of nanoporous polymeric materials by reactive encapsulation of an inert solvent using a step-growth cross-linking polymerization reaction carried out until completion without micro/macroscopic phase separation. Key structural features of the porous materials synthesized in this way were investigated by scanning electron microscopy (SEM) after extraction and supercritical drying using carbon dioxide. Micrographs of the materials synthesized using the reactive encapsulation technique showed that materials with pore sizes less than 100 nm are obtained. Micrographs also showed that the reactive encapsulation technique can be employed to synthesize nanoporous polymeric materials of desired porosity and pore size by changing the solvent content.