Dielectric Spectroscopy Study On Phase Transition Of Long Chain Alkyl Trimethyl Quaternary Ammonium Salt And Modification Of Graphite Oxide

In the long-chain alkyl trimethyl quaternary ammonium salt-modified graphite oxide sample dielectric spectroscopy,we see a signal which does not vary with frequency.We believe it is a phase transition signal.This signal must come from long chain alkyl trimethyl quaternary ammonium salt.In order to study the phase transition,we use the method of DSC to characterize dodecyl trimethyl ammonium chloride,myristyl trimethyltetradecyl ammonium chloride and cetyl trimethyl ammonium chloride powder samples.We see a pair of peaks in the absorption cycle,indicating the presence of the latent heat of the sample.We also get the phase transition temperature range.We characterize of cetyl trimethyl ammonium chloride structural phase transition temperature by situ Temperature XRD and find huge changes before and after the phase transition temperature.At the large angle area crystallinity of the phase gets a little disordered.At the small angle area peaks move to small angle area.Broadband dielectric spectroscopy gives a description of the phase transition at various frequencies.We get a definite phase transition temperature.We also find a arelaxation peak at low temperature region.Activation energies of three samples are calculated by Arrhenius relations fitting.We prepared the GO sample with Hummers method and then we hydrogenated GO under the condition of 300? 10 Mpa,400? 10 Mpa and 500? 10 Mpa.XRD and FTIR was used to describe spacing between layers and functional groups of GO and Graphane.SQUID was used to measure the magnetism of GO and Graphane.The result shows that ferromagnetism of Graphane is a hundred times of that of GO.The main sources of ferromagnetic are carbon-hydrogen bonds formed after hydrogenation reduction.But during the experiment we also find the bonds are unstable.Fluorinated graphite oxide samples are synthesized and characterized by XRD,FTIR and Roman Spectra.We also compared the difference between the product of the upper and lower layers.Samples which are oxided 12 hours are better.Samples which are oxided with higher fluorination raw material are more unstable.In addition,the purification process plays an important role to improve the purity and characterization of samples.