Synthesis of carbon/carbon composites by hydrothermal carbonization using starch as carbon source

Abstract

Carbon/carbon (C/C) composites were fabricated by hydrothermal carbonization (HTC) using starch as the carbon source. The C/C composites were densified by 10 cycles of HTC treatment, each consisting of 2 hours. The density of the composites can achieve 1.23 g cm⁻³ and the porosity is about 10.9%. The matrix of the C/C composites is an amorphous carbon functionalized with hydroxyl and carboxyl groups. The flexural strength and modulus of the composites can reach 146 MPa and 9.6 GPa. The fracture of the composites presents a typical pseudo-plastic fracture characterization. These results suggest that the new C/C composites can be used as engineering materials and biomedical materials. The HTC technique is an efficient and environmental-friendly route to fabricate C/C composites.