Preparation of porous SiC ceramics from waste cotton linter by reactive liquid Si infiltration technique

Porous carbon and porous silicon carbide with homogenous microstructure are prepared from cotton linter and phenolic resin through mold-stacking, solidification, carbonization and liquid Si infiltration process. SEM observation reveals that the irregular interconnected pores of carbon preparation were originated from the random arrangement of cotton linter fiber and different carbonization shrinkage. After the liquid Si infiltration process, the porous carbon was converted into dense SiC/Si composites. The porous SiC was formed during the Si-removing process at higher temperature. The result shows that open porosity of porous silicon carbide increases as Si-removing time increase, while the bending strength and the fracture toughness decrease.

Research highlights▶ We reported to prepare porous SiC ceramic from the cotton linter, a kind of byproduct from the cotton textile production. Porous SiC with homogenous microstructure is prepared through a combination of carbon thermal reduction reaction and liquid phase silicon zing using waste cotton linter as raw material. This study will help improve the utilization of natural resources and reduce environmental pollution. ▶ Theory of cotton linter ceramic is brought forward, which can increase special uses of cotton linter. It is an original and creative idea that using the cotton linter as a kind of material for producing high property ceramics. ▶ The porous carbon produced by carbonized cotton linter is easy to manufactured, and the microstructure of which changes the uneven nature of the similar products that produced by wood and other natural cellulose, therefore, it has good prospects for applications. ▶ This paper combines macroscopic mechanic design and microscope structure design on ceramics, and the implement of integrated design of multi-scale ceramics and function ceramics can open new paths for production of strong hard porous materials.