Investigation of solvent type effect on the structural properties of bio-polyol-based carbon foam

Abstract

Nowadays, the increase in studies about the improvement of technology has enabled the development of new materials and their properties. Natural/industrial/pyrolytic graphite, graphite/carbon foams, diamond, graphene, carbon nanotube/nanofibers and carbon composites are carbonaceous materials used in the production of electronic devices and thermal management applications. As oil resources are beginning to diminish, the liquefaction of biomass is becoming a new area of biomass usage. In thermochemical conversion processes of biomass, biomaterials are obtained by using solvolysis liquefaction process, which is a subsection of direct liquefaction process. Cellulose, lignin and hemicellulose in the biomass structure contain a large number of hydroxyl groups. Conversion of liquefied biomass to biopolymers takes place through hydroxyl groups. Within the scope of the study, solvolytic liquefaction of hornbeam tree sawdust obtained as industrial waste was carried out in order to prepare carbon foam from low cost and renewable materials. The effect of solvent type (phenol and phenol + tar mixture) on the structure of carbon foams was investigated in the solvolytic liquefaction process. In order to overcome the irregularities in the foam structure as a result of the addition of tar to the synthesis medium, the processes were repeated by increasing the amount of surfactant. Elemental analysis, scanning/transmission electron microscopy, nitrogen sorption, and x-ray diffraction analyses were performed for the carbon foam characterization, compression strength and density measurements were also carried out. According to the characterization data, it is concluded that biomass-based carbon foams with adjustable crystallographic, morphological and structural properties can be produced by changing the solvent type and the amount of surfactant.