A comparative study on the formation process of graphite oxide (GO) prepared both from natural graphite (NG) and expandable graphite (EG) was accomplished by XRD and XPS techniques. It reveals that expandable graphite...A comparative study on the formation process of graphite oxide (GO) prepared both from natural graphite (NG) and expandable graphite (EG) was accomplished by XRD and XPS techniques. It reveals that expandable graphite, a graphitic intercalated compound (GIC), can have easy access to an interlayer oxidation leading to higher extent of oxidation within shortened time interval. An XPS study on GO surface shows a complicate chemistry. Much more involved is the dominated graphitic carbon accumulated on the surface accompanied with a variety of oxygen containing functional groups along with oxidation. The bonding state in the surface is mostly in control of the single bond linkage, C O.展开更多
Objective,Used the TG/DTA curves and XRD patterns to identify five kinds of free anthraquinones.Method,The thermograms,differential thermograms and X-ray powder diffraction patterns were obtained by thermal analyzer a...Objective,Used the TG/DTA curves and XRD patterns to identify five kinds of free anthraquinones.Method,The thermograms,differential thermograms and X-ray powder diffraction patterns were obtained by thermal analyzer and X-ray powder diffraction analyzer.Result,By analyzing the TG/DTA curves and XRD patterns of the free anthraquinones(Rhein,Emodin,Aloe-emodin,Chrysophanol and Physcion)from Rheum,the results showed that they had the similar TG curves,however,due to the substituents attached on the 1.8-dihydric anthraquinones are different,every sample had different weight lose.All the DTA curves of free anthraquinones had two obviously characteristic peaks,but there were obviously differences on curvilinear shapes,peak location and peak values.The X-ray powder diffraction patterns of free anthraquinones have their own characteristic and very obvious.Conclusion: According to the differences in the thermal and XRD properties of five free anthraquinones,the kind of free anthraquinones could be easily identified and they can be used as correspondence free anthraquinones’s characteristic fingerprint patterns.展开更多
文摘A comparative study on the formation process of graphite oxide (GO) prepared both from natural graphite (NG) and expandable graphite (EG) was accomplished by XRD and XPS techniques. It reveals that expandable graphite, a graphitic intercalated compound (GIC), can have easy access to an interlayer oxidation leading to higher extent of oxidation within shortened time interval. An XPS study on GO surface shows a complicate chemistry. Much more involved is the dominated graphitic carbon accumulated on the surface accompanied with a variety of oxygen containing functional groups along with oxidation. The bonding state in the surface is mostly in control of the single bond linkage, C O.
文摘Objective,Used the TG/DTA curves and XRD patterns to identify five kinds of free anthraquinones.Method,The thermograms,differential thermograms and X-ray powder diffraction patterns were obtained by thermal analyzer and X-ray powder diffraction analyzer.Result,By analyzing the TG/DTA curves and XRD patterns of the free anthraquinones(Rhein,Emodin,Aloe-emodin,Chrysophanol and Physcion)from Rheum,the results showed that they had the similar TG curves,however,due to the substituents attached on the 1.8-dihydric anthraquinones are different,every sample had different weight lose.All the DTA curves of free anthraquinones had two obviously characteristic peaks,but there were obviously differences on curvilinear shapes,peak location and peak values.The X-ray powder diffraction patterns of free anthraquinones have their own characteristic and very obvious.Conclusion: According to the differences in the thermal and XRD properties of five free anthraquinones,the kind of free anthraquinones could be easily identified and they can be used as correspondence free anthraquinones’s characteristic fingerprint patterns.
