ИСТИНА

Graphite oxide (GO) recently attracted great attention because it is considered as a source of graphene oxide which is used for graphene preparation. Structure and properties of GO strictly depend on the way of it synthesis and type of graphite. Despite numerous studies devoted to the properties of GO, there is a lack information about the influence of synthesis duration on graphite structural transformations and on properties of GO. The aim of this work is to find out the correlation between synthesis duration and physicochemical properties of GO. GO was synthesized by modified Hammers technique using natural flaky graphite. Synthesis duration was 1, 2, 4, 8, 16, 24, 48, 72 hours and 1 week. The GO films were prepared by sedimentation of GO dispersed in methanol. GO and GO films were studied by means of XRD, IR and Raman spectroscopy, SEM and DSC. GO phase appears on XRD patterns after 1 hour after addition of KMnO4 and after 12-16 hours graphite turns to GO completely. Temperature of GO decomposition decrease while the synthesis duration becomes longer and reaches the minimal value for GO synthesized for 12 hours. For this sample, maximal amount of epoxy groups is observed. Further increase of synthesis duration leads to increase of GO decomposition temperature. All the GO samples allow to obtain GO films which possess layered structure. The optimum synthesis duration for GO films formation was evaluated and thermal properties of GO films were studied.