Synthesis of nanographite by laser induced thermal expansion of H2SO4 intercalated graphite lattice

TL;DR

This study explores how laser irradiation induces thermal expansion in H2SO4 intercalated graphite, leading to nanographite synthesis through a rapid, temperature-triggered reaction that causes violent expansion and morphological changes.

Contribution

It provides experimental insights into the laser-induced expansion mechanism of intercalated graphite, highlighting a threshold temperature and the process dynamics for nanographite production.

Findings

Threshold temperature for expansion is about 140°C.

Rapid heating causes violent expansion and gas release.

Morphological analysis reveals structural changes during irradiation.

Abstract

We have experimentally investigated the expansion mechanism induced by laser irradiation of H2SO4 intercalated graphite. Intercalated graphite materials irradiated by laser allows to study reactions occurring in confined chemical conditions. We find that the laser-assisted reaction process is characterized by a threshold temperature of about 140{\deg}C followed by a fast rate of heating which produces a large amount of overheated gases and causes a violent expansion of the graphite crystal. We investigate the morphological changes undergone by irradiated graphite filaments using a combination of thermal and visible imaging technique which allows for the quantitative determination of temporal evolution of the thermal field during the heating stage and exfoliation of the grain.