ИСТИНА

Graphite nitrate, intercalation compound with nitric acid, is known for many years, and basic principles of its formation, including intercalation threshold have been stated [1-3]. Although most studies were carried out using one type of graphite, natural flaky one or highly oriented pyrolytic graphite (HOPG), and different results were reported. Two probable reasons of these differences are the synthesis technique and graphite structure. The present work is devoted to determine the role of graphite nature in intercalation process. The phase composition of graphite intercalation compounds synthesized in acid of the same concentration for 24 hours was the same no matter natural graphite or HOPG was used. The only exception is 80% HNO3 where HOPG could be intercalated to form IV stage of graphite nitrate whereas in case natural graphite the formation of mixture of III and IV stages was observed. The opposite situation occurs for the synthesis time of 1 hour. In 98% nitric acid all graphite materials eneble to form graphite nitrate of II stage. In 80-90% solutions, the phase composition of the samples prepared using natural graphite is always represented by higher stages of intercalation compound.