Characterization of meso-carbon microbeads prepared by emulsion method

Abstract

This article describes the preparation of meso-carbon microbeads by the emulsion method from three kinds of bulk-mesophase pitches (coal-tar, FCC-decant oil, and naphtha-tar pitch), and their physicochemical properties. The meso-carbon microbeads were obtained as the spherical particles from respective pitches in yields of 65%–90%. The meso-carbon microbeads from the coal-tar and FCC-decant oil pitches had a larger amount of quinoline insolubles than those of starting pitches, while that from naphtha-tar pitch was approximately constant with heat treatment temperature. The coal-tar and FCC-decant oil based microbeads had an optically anisotropic texture with different domain sizes, whereas the naphtha-tar based microbeads exhibited an optically isotropic texture. The results of FTIR and ash content suggest that a permeation of silicone oil during heat treatment causes a distortion and expansion of the lamellar structure for the naphtha-tar based microbeads. Furthermore, it was found from FTIR and 13C-NMR analysis that the coal-tar based microbeads had the highest aromaticity and that the naphtha based microbeads had the largest amount of aliphatic carbons, such as methyl, methylene, and alicylic groups.