True density of nanoporous carbon fabricated from rice husk

Abstract

The accurate estimation of true density is a fundamental problem for nanoporous carbon (NPC) materials because of helium adsorption. In this study, we developed a method for measuring the true density of NPC fabricated from rice husks based on a gas constant-volume expansion method. The proposed method considers helium adsorption on NPCs. The obtained results indicated that NPC fabricated from rice husk with a 2986 m2/g specific surface area has a true density of 2.095 g/cm3 as determined by the proposed method. In contrast, using the commercial helium-substituted method, the true density was measured as 2.437 g/cm3. The average standard deviation values using the proposed method were 0.015–0.027, whereas those using the commercial helium-substituted method were 0.024–0.138. These results indicated that accurate determination of the true density of NPCs was accomplished by the proposed method.