Formation Mechanism of Pores Contained in PVDF-based Carbon Films Derived through Chemical and High-temperature Heat-treatments

Abstract

A mesoporous carbon can be derived from poly(vinylidene fluoride) (PVDF) via chemical dehydrofluorination (DHF), carbonization at high temperature and activation in carbon dioxide gas. The pore size of this activated carbon is determined by the pore size of the carbon before activation and controllable by adjusting the extent of DHF. The present study has aimed at elucidating the formation mechanism of pores in this carbon before activation. By comparing the porous structures of the carbon derived in this way and the carbon derived by applying the DHF treatment to a PVDF solution, it has been shown that the inhomogeneity in the extent of DHF between the amorphous and the crystalline regions of PVDF is the key factor of the formation of pores. It has been also demonstrated that this carbon before activation shows a selective absorption.