Effect of activated carbon particle size on the thermo-foaming of aqueous sucrose resin and properties of the carbon foams

Abstract

The carbon foams prepared by the thermo-foaming of dispersions of activated carbon (AC) powder of various average particle sizes (4.9 to 15 lm) in an aqueous sucrose resin were characterized. The stability of the wet foams increased with the decrease in the AC particle size as finer particles preferentially adsorbed on the air-resin interface. The particle agglomeration leading to the foam collapse was observed at lower AC powder to sucrose weight ratios with the finer powders. The cell size (0.33-2.34 mm), foam density (0.1151-0.2281 g/cm 3 ), and compressive strength (0.16-2.77 MPa) of the carbon foams depend on the AC particle size as well as the AC powder to sucrose weight ratio. The thermal conductivity of the carbon foams (0.036-0.049 W m À1 K À1 ) was much lower than that of the vitreous carbon foams of similar densities. The foams were fire resistant and amenable to machining with the conventional machines and tool.

Synthesis of Micro- and Mesoporous Carbon Foams with Nanodispersed Metals for Adsorption and Catalysis Applications

“…This means that the cells are not sealed, eventually allowing the flowing of gases or liquids through the material. A similar morphology has been identified in previous works using different additives [ 31 , 35 , 36 , 37 , 44 , 45 ]. The boundaries of cells consist of walls that become ligaments when the windows are large enough and struts.…”

“…Sucrose-derived carbon foams are typically characterized by relatively large structural cells that can confer low mechanical resistance to the material. To address this drawback, different carbonaceous products (active carbon, graphite powder, carbon nanotubes, carbon fibres and others) have been used as reinforcements to improve the strength of the final CFs [ 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 ], which display increased densities and reduced cell sizes.…”

Graphene-reinforced carbon composite foams with improved strength and EMI shielding from sucrose and graphene oxide

“…The continued GO catalyzed -OH condensation reactions are responsible for the decrease in foam setting time with an increase in GO concentrations. The time for foaming and foam setting is lower in the case of sucrose-GO system when compared to the AC powder-sucrose and milled carbon fiber-sucrose systems, even though, the foaming temperature is lower [35][36][37]. This is due to the higher catalytic activity of GO because of the presence of a large number of acidic functional groups.…”

“…Reinforcement such as carbon fiber, carbon nanofiber, carbon microspheres, multi-walled carbon nanotube, ceramic whiskers, etc., is used to increase the compressive strength of carbon foams prepared from fossilbased precursors [26][27][28][29][30][31][32][33][34]. Reinforcing carbon additives such as activated carbon powder and milled carbon fiber are studied to improve the compressive strength of carbon foams from sucrose [21,[35][36][37].…”