  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.
