Preparation of exfoliated graphite using Sri Lanka natural graphite

Abstract

Graphite Intercalation Compounds (GIC) with HNO3 were chemically obtained using different morphologies of natural graphite from Sri Lanka, Madagascar and Krömful. X-ray powder patterns of the products showed the formation of second stage GIC (HNO3). These compounds were used to produce exfoliated graphite at 550°C in air. The expansion ratio was measured and compared with different types of natural expanded graphite. Accordingly, the pellet type Madagascar graphite and KahatagahaKolongaha shiny, slippery, fibrous graphite (KSSI; one of the morphology of natural graphite of Sri Lanka) showed the greatest volumes of expansion. The samples with the largest average particle sizes had the largest expansion volumes, which can be explained by the proportionality between structural, morphological and textural characteristics of expanded and raw graphite types