Study On The Interaction Between Oligomers And Transition Metal Chlorides

The present work is consisted of two sections. Section one includes three parts and section two includes two parts.In the first section, we revealed three important and novel findings regarding the effect of ferrous chloride (FeCl2) on thermal properties of polyvinyl chloride (PVC). First, the glass transition temperature of PVC upon composite with FeCl2exhibited a noticeable increase, along with improvement of crystallization degree and modification of surface morphology. Second, a much lower degradation temperature and an almost entire degradation of PVC occurred in the presence of FeCl2in nitrogen. Third, the thermal degradation products of the PVC in the composite were greatly changed compared to free PVC, indicating that FeCl2could prevent the cleavage of PVC chains under mass spectrometry conditions. It is very interesting that FeCl2plays an opposite role in modifying the thermal stability of PVC in the two experiments. We believe that this work is of general significance because our findings will be helpful for improving PVC materials.In the second section, we were devoted to the construction of nickel oxide (NiO) nanopolyhedral structures through a simple, efficient and environmentally friendly one-step process. Initially, a series of intimate mixtures of nickel chloride (NiCl2) and β-cyclodextrin (β-CD) with different initial molar ratios were used as precursors. By simply sintering the precursors, we successfully obtained NiO nanocrystals (nanooctahedra and nanospheres) with smooth surface and uniform size distribution. Control experiments showed the formation, morphology and grain size of NiO nanocrystals can be finely modulated by changing two parameters:the initial molar ration of NiCl2to β-CD and the sintering time. The former is a decisive factor for creating the NiO nanopolyhedral, while the latter is a key factor for regulating their size and shape evolution. Moreover, we found that the role of β-CD can be played, but less well, by other carbon sources such as active carbon and glucose. Several independent experiments (FTIR spectra, conductivity and thermogravimetric analyses) were done to understand the mechanism of this role. Our data suggested that β-CD produced a stronger interaction with NiCl2than the other two carbon sources, leading to an earlier transformation from NiCl2to NiO. Further, this nanooctahedral material exhibited a very small hysteresis loop below 500Oe at300K, indicating ferromagnetic behaviour, which is different from the antiferromagnetic behaviour of bulk NiO materials. Electrochemical tests demonstrated that the NiO nanooctahedra and nanospheres have high lithium storage capacity. Also, the NiO nanospheres presented very low irreversible capacity loss and good cyclability. Therefore, it gives an impression that they are promising anode materials of rechargeable lithium-ion batteries, for high power applications in particular. We believe that these results will increase our understanding of the relationship between structures, properties and functions of transition metal oxide nanomaterials.