Structure and thermal properties of poly(ethylene oxide)-intercalated graphite oxide

Poly(ethylene oxide)-intercalated graphite oxides (PEO-intercalated GOs) with two different c-axis repeat distances have been synthesized and characterized in detail. IR spectra and X-ray diffraction patterns obtained at various temperatures of PEO-intercalated GO samples with two different I-c values suggest that the conformation of the intercalated PEO is gauche in both PEO-intercalated GO samples. This means that in PEO-intercalated GO with the larger I-c value, PEO exists as double layers of zigzag chains in a GO gallery. From the DSC data and in situ X-ray diffraction measurement at various temperatures, it was found that PEO-intercalated GO with the smaller I-c value decomposed into GO and PEO at around 162 degrees C and the decomposition of that with the larger I-c value occurred at around 185 degrees C, accompanied by the destruction of the carbon skeleton. The products obtained by the thermal decomposition of PEO-intercalated GO containing copper acetate are copper or copper oxide fine particles supported on an amorphous carbon matrix, depending on the ambient atmosphere. The sizes of the fine particles calculated using Scherrer's equation were about 7 nm for CuO, which is in good agreement with that observed by TEM, and about 20-30 nm for Cu2O and Cu. Copyright (C) 1997 Elsevier Science Ltd.