温度对聚丙烯酰胺溶胶与凝胶粘度的影响

Key Words:Graphite oxide; GO; In situ Fourier transform infrared spectroscopy; In situ; FT-IR spectroscopy; Wide-angle X-ray diffraction; WAXD

Abstract:The thermal reduction behavior of graphite oxide (GO) film in an air atmosphere during a continuous heating process was monitored in situ using temperature-dependent infrared (IR) spectroscopy and synchrotron radiation wide-angle X-ray diffraction (WAXD) techniques. The results show that most of the water adsorbed by the GO sheets is removed by heating them to 130 degrees C. The dehydration process leads to a slight decrease of the interplane distance of the GO sheets. The IR data suggest that the thermal reduction occurs starting at 160 degrees C. The synchronous change of the of hydroxyl and carbonyl stretching mode (nu(-OH) and nu(C=C)) bands of GO between 160 and 210 degrees C suggest that the recovery of conjugated structure is mainly due to the reduction of -OH groups in this temperature region, in which the d spacing has not been affected. When the temperature reaches 210 degrees C, the rapid reduction of C=O groups together with the removal of the residual -OH and ether (C-O-C) groups leads to the sudden collapse of the GO sheets. Based on these findings, we present a schematic of the thermal stability of GO film in a continuous heating process, in which the thermal-induced chemical and crystallographic structural changes of the GO film have been correlated.

Volume:68

Issue:5

Translation or Not:no