Three-dimensional, high-porosity conducting skeletal structure from biodegradable microparticles with vapor-phase polymerized conformal surface layer

Abstract

Three dimensional (3D) electric conducting porous structures are a promising platform that could be utilized in emerging 3D structural electronics, energy storage systems, and biomedical applications. A poly(3,4-ethylenedioxythiophene)/silica (PEDOT/SiO2) composite with foam-like conducting open skeletal structures and pore sizes exceeding 100 mm is presented. A two-step procedure was used to prepare this functional porous structure. First, a conformal coating layer was synthesized via vapor-phase polymerization onto a randomly sized biodegradable microparticle assembly. Vapor-phase polymerization allowed for facile coating of the nanoscale layer in a relatively short processing time (30 min). At this stage, non-invasive chemical modification can be also accomplished on the surface of microparticles that have complex surface morphology. Secondly, biodegradable microparticles were selectively removed to form a high-porosity skeletal conducting structure. The composite demonstrated structural integrity despite an unusually high porosity of greater than 96%, which was confirmed through micro-computed tomography (CT). The results show that this foam-like conducting open skeletal structure of the PEDOT/SiO2 composite is a good candidate for new applications. (C) 2016 Elsevier Ltd. All rights reserved.