Research On The Interaction Between Polar Solvents And Graphite Oxide Layers

The properties and applications of GO are closely related to its interlayer spacing.GO contains many functional groups,which makes polar solvents intercalated easily and causes increasing of GO interlayer spacing as a result.The variation of GO interlayer spacing will determine the existence form of polar solvents in GO interlamination.The interaction between solvent molecules and GO layers after GO adsorbing polar solvents C₂H₆O₂?EG?,C₃H₇NO?DMF?,C₅H₉NO?NMP?and water molecules are calculated through molecular dynamics simulations in this paper.Fourier transform infrared spectroscopy and X-ray diffraction have been conducted to research the variation of groups and structures of GO after absorption.The variation of GO interlayer spacing caused by the interaction between polar solvents and GO layers,as well as the effects have been researched by molecular dynamics simulation.The results show that the increasing number of GO layers leads to compact structures of GO.The interlayer spacing of GO adsorbed solvent molecules is correspond to the minimum molecular size of three-dimension directions.Adsorbing more molecules results in larger interlayer spacing of GO.Most of the molecules tend to parallel to the carbon plane of GO and as adsorbed more molecules into the interlamination,several molecules perpendicular to the carbon plane and large space is formed between two layers.It is also found that the other relative large molecules play a crucial role in increasing interlayer spacing compared to water molecules when GO adsorbed binary mixture solvents.The hydrogen bonds interactions of GO and water molecules,the water behaviors,and detailed information of structures for GO confined water molecules have been researched in this paper.The variation of GO interlayer spacing are revealed in the molecule scale.The results show that the binding of GO and water molecules is essentially controlled by hydrogen bond interactions involving both functional groups and water molecules.With the increase of water content,the clusters of water molecules become more evident.They transform from bound to GO layers to free state,which will cause it difficult to remove water molecules out of GO in low water content.As a result,water molecules adsorbed into GO interlamination will enlarge the interlayer spacing.The results in this paper provide theoretical foundation for the applications of GO and also provide some referential for modifications of graphene-based materials and preparation of nanocomposite.