Honeycomb carbon foams with tunable pore structures prepared from liquefied larch sawdust by self-foaming

Honeycomb carbon foams with tunable pore structures were prepared from larch sawdust. The pore structure was controlled, on the nanometer scale, by addition of polyethylene glycol (PEG). The PEG molecules were dispersed and stretched in the aqueous phenolic resin system, occupying space. Some of the PEG molecules self-assembled to form an ordered net and banded structure, and then interacted with the resin to form stable polymers. Well-connected honeycomb cells and excellent pre-pore structures were formed simultaneously in the carbon foams through self-foaming. Many micropores and mesopores were present in the ligaments, nodes, and cell walls after carbonization. Graphitic-like regions were present in samples carbonized at 800 degrees C, and the surface areas and pore volumes of the carbon foam were up to 1580.97 m(2)/g and 0.885 cm(3)/g, respectively. The number of mesopores and the extent of ordering of the carbon foam increased with PEG content; these changes also led to higher adsorption of vitamin B-12. (C) 2014 Elsevier B.V. All rights reserved.