Investigation Of The Mechanism Of Unique Temperature-Responsiveness OfMetal-Cholate Supramolecular Hydrogels And Application Of Electrode Materials Synthesis By Hydrogel Template Method

This dissertation focuses on the important biological sodium cholate activemolecules, hydrogels are facilely designed via supramolecular self-assembly ofsodium cholate and metal ions, Special temperature-responsiveness is the strength ofthe hydrogels increases with increasing temperature, and we gave mechanismexplanation at the molecular level. The self-templating approach based onmetal-cholate supramolecular self-assemblies was reported. in which metal ions serveas both the inorganic precursor and constituent of template, Such hydrogel serve assoft template in the synthesis of one-dimensional nano-material as electrode forsupercapacitor and its electrochemical performance were studied. Lastly, A facilemethod is presented to prepare NiO nano-materials involving only solvothermalsynthesis method without any templates or precipitate-controlling agents, It’s a moreeasily controlled synthesis of electrode nano-material. This paper includes thefollowing four parts:1. Definition of supramolecular hydrogels, driving force of self-assembly,pH/temperature-responsiveness of supramolecular hydrogels and hydrogel based onbioactive molecules were systematically introduced in first chapter, we also reviewedgel as template role in the synthesis of applied nanomaterials. At the same time, thesupercapacitor characteristics, classification, and research progress on electrodematerials of supercapacitor also be described. The ideas to prepare hydroxidenanomaterials as electrode for supercapacitor based on metal-cholate self-assemblysoft templates were put forward. Finally, we summarized outstanding advantages ofsolvothermal method in preparaing nanomaterials.2. Metal-Cholate supramolecular hydrogels were prepared by mixing solution ofsodium cholate and metal ions, Formation was investigated, Microstructurecharacteristics of hydrogel and nanofibers were observed. The arrangement of thecholate and metal ions was proposed, Rheologica measurements revealed that thestrength of the hydrogels increases with increasing temperature, while thefluorescence of the gels increased as well. Increasing the temperature also increased the gel formation rate. The critical micelle concentration of sodium cholate solutiondecreased slightly with increasing temperature. we propose that the increasedhydrophobicity of cholate ions with increasing temperature leads to stronger hydrogenbonding between cholate ions, which accounts for the unique heating-enhancedgelation behavior.3. Nano-Co（OH）₂and Ni（OH）₂were prepared via a facile strategy, in which thecobalt-cholate and nickel-cholate self-assembled supramolecular nanofirbers serve asself-template which were obtained by mixing sodium cholate solution with cobaltnitrate or nickel nitrate solution, and then the samples were obtained by addingdepositing reagents NH₃H₂O under ambient conditions. metal ions can serve as boththe inorganic precursor and constituent of the template. This self-template preparationmethods provide a simple and convenient way to synthesis inorganic nanomaterials.4. The purpose of fourth chapter is to describe solvothermal method to preparenickel hydroxide submicro-flakes and nanoparticles, and NiO micro/nano-materialswere obtained by thermal decomposition steps, Which have the advantages of needn’tprecipitate-controlling agents or template compared with traditional solvothermalmethod, and its electrochemical capacitance performance as the active material isstudied. To improve the performance of the material, graphene oxide was introducedin the reaction process, and obtained NiO/graphene composite material of thesandwich structure, Specific capacity and cyclic stability were improved.