Microporous nanoparticle emulsion thermosets for multi-material, multifunctional porous nanocomposites*

We have developed microporous nanoparticle emulsion thermosets (MiNET), a new class of nanocomposites made from epoxies and nanoparticles, a liquid porogen, and a small quantity of surfactant. These ingredients form an intermediate between a conventional surfactant a Pickering emulsion to create a bicontinuous network of oil and epoxy composite throughout the processing. After a room temperature cure and usage of different functional nanoparticles, based on the performance requirements of a given application, it is possible to design a composite with a range of functionality like flexibility, inertness, and conductivity. Further extraction of the oil phase through rinsing, MiNETs can be converted into porous (30~60% open volume) structures without considerable volume shrinkage (~1~5%). The pore size (between 100~10,000 nm) and chemical functionality of the pores is tunable by the constituent nanoparticles. Simultaneously, the matrix resin can change mechanical properties and use of silicone nanoparticles as a filler can establish flexible behavior. These novel thermosets molded into various complex forms. For example, we have demonstrated parallel-processed electrospray emitters at micrometer scale and Carbon fiber nanocomposites with MiNET as a matrix.