PMMA-Templated Carbon Gel Monoliths with Independently Tunable Micro-, Meso-, and Macropores

Abstract

Independent controlling of micro- (<2 nm), meso- (2–50 nm) and macropore (>50 nm) structures in monolithic carbon gels (CGs) was achieved by simply adjusting three independent synthetic parameters. Monolithic composites of resorcinol–formaldehyde (RF) gel and poly(methylmethacrylate) (PMMA) particles were prepared and subsequently carbonized yielding carbonized monoliths. Macropores were successfully introduced as traces of the PMMA particles without hardly affecting the structures of the micro- and mesopores of CGs. The size of the macropores can be controlled in the range of 0.05–1.0 µm by adjusting the size of the PMMA particles. The size of the mesopores can also be controlled in the range of a few to a few tens of nanometers by adjusting the concentration of the catalyst in the starting RF solution. Micropores can be efficiently developed by activating the CG monoliths with CO₂ gas yielding monoliths having extremely high BET surface areas up to ∼3000 m² g⁻¹.