Controlling the Porosity and Strength of Liquefied Spruce Tree Sawdust Based Carbon Foams via Changing Surfactant Amount

Abstract

Recently, carbon and graphite foams were reported to be excellent for numerous thermal, mechanical and electrical applications such as high-temperature insulation, fuel cell electrodes, heat exchangers, brake discs, engine parts and bone surgery materials. In this study, the effect of surfactant amount was studied to examine the adjustability of the structure of the carbon foams with hard and less porous structure produced by the liquefaction of spruce tree sawdust in the presence of pyrolytic oil. When the phenol + pyrolytic oil mixture was added instead of the phenol in the synthesis step, the foaming agents could not abandon the structure, consequently, the hard polymeric structure was produced. Because of the gas molecules that cannot overcome the increasing surface tension on the polymer surface, the formation of pores on the surface is restricted during the synthesis with the addition of a standard amount of surfactant. When the surfactant amount was increased, foaming was successfully carried out due to the dissociation of gas molecules from the structure by overcoming the surface tension in the polymer matrix. As a result, it was proved that by changing the synthesis conditions, the surface area, porosity (%), compressive strength, elemental carbon content and crystalline structure of carbon foams can be adjusted due to the application area and desired properties. © 2021, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG.