LASER-ASSISTED EXFOLIATION OF POTASSIUM-AMMONIA-GRAPHITE INTERCALATION COMPOUNDS

Potassium-ammonia-graphite intercalation compounds (K-NH3-GIC) synthesized from small natural graphite particles from China were rapidly heated by a cw-Nd:YAG laser beam (1.056 mum) in an Ar purge environment to yield exfoliated small graphite particles as sources for electrical conductive films. The laser heating method was demonstrated to be effective for exfoliation of K-NH3-GIC prepared from natural graphites in sizes of under 37 mum, 37 approximately 63 mum, and 63 approximately 88 mum, whereas no exfoliation of these graphites occurred by either gas burner heating or electric furnace heating. The results also show that K-NH3-GIC prepared from natural graphite 350 approximately 500 mum in size was exfoliated to 32-fold of the volume of feed natural graphite. This exfoliation ratio is 2.6 times larger than the ratio obtained by the gas burner heating method.