Burn-Dry—Fabrication of Porous Carbon Networks via Polymer-Templated Rapid Thermal Annealing

Effective structural control of porous materials, by a selection of templating or template-free fabrication strategies, may produce materials with outstanding properties that are inaccessible in the bulk. However, existing preparative methods typically involve multiple, tedious steps that limit scalability. This trade-off between structural control and procedural simplicity for creating porous structures presents an outstanding challenge for researchers. Herein, a “burn-dry” process is introduced as a versatile, rapid strategy involving polymer-templated rapid thermal annealing (RTA) to fabricate porous networks of carbon-based materials. As a model system, we utilize a polystyrene/poly(vinyl methyl ether) blend loaded with reduced graphene oxide (rGO) particles to generate macropores on the size of phase separation, with the objective of understanding the impact of polymer mobility on templated rGO morphologies. We found that both particle loading and annealing rate contribute to kinetic trapping and network formation, and studied their impact on macropore formation using glass transition temperature as a measure of polymer mobility. Without changing the template composition and processing conditions, we demonstrate applicability of burn-dry to other carbon materials, such as graphene oxide, carbon black, carbon nanopowder, and multi-walled carbon nanotubes. The sequential templating and template degradation induced by RTA can be accomplished in less than 10 minutes. Although established in the semiconductor industry for doping inorganic materials, our use of RTA when coupled with polymer templates holds promise for large-scale fabrication of porous structures with its minimized thermal budget, high throughput, and optimized productivity/cost ratio. This work will serve as a powerful platform for the rapid templating of hard materials, and will inspire other simple, scalable approaches for creating porous structures. In addition, the impact of polymers on the electronic properties of all-carbon materials will be described.