Facile synthesis of dual micro/macroporous carbonaceous foams by templating in highly concentrated water-in-oil emulsions

A simple method to synthesize carbonaceous porous foams is described, forming simultaneously micropores and macropores, by polymerizing in the external phase of highly concentrated water-in-oil (W/O) emulsions, and pyrolizing the resulting macroporous polymer foam. Highly concentrated W/O emulsions were prepared with 1,1-dichloroethene monomer in the external phase, which was polymerized at low temperature by a redox initiator. Monolithic low-density macroporous foams were obtained after polymerization and purification by soxhlet extraction. These foams were mainly macroporous, with low surface area (approximate to 28 m(2) g(-1)) and negligible microporosity and mesoporosity, as expected. The size (2-10 mu m) and morphology of the macropores were consistent with the droplet size (2-10 mu m) and shape(polyhedral) of the highly concentrated W/O emulsions. Pyrolization of the macroporous polymer foams allowed the formation of micropores while the macroporous texture was preserved, and consequently, dual micro/macroporous carbonaceous monoliths were obtained, with a large surface area (>800 m(2) g(-1)). These materials were characterized by optical microscopy, scanning and transmission electron microscopy, N-2 sorption isotherms, infrared absorption spectroscopy and elemental analysis. The influence of pyrolysis temperature (300, 400 and 500 degrees C) was studied. (C) 2013 Elsevier Inc. All rights reserved.