Studies On Synthesis, Mechanisms And Properties Of Inorganic/Dye Hybrids

In this dissertation,new strategies for synthesizing inorganic materials in mixed solvents have been developed to synthesize organic crystals and inorganic/organic materials with novel morphologies and hierarchical microstructures.Cobalt carbonate as a kind of the important inorganic mineral models has been selected to investigate the growth-controlled process of crystals in the mixed solvent system.A series of cobalt carbonate particles with different shapes have been prepared by the combination of classical hydrothermal method and mineralization process,which can be calcined into nanoporous cobalt oxide crystals.Then,the mixed-solvent strategy has been successfully extended to the controlled crystallization of organic materials. The shape and growth process of the organic dye crystals can be well controlled by the simple recrystallization method.Based on understanding on the growth habit of inorganic and organic materials,the colorful zinc oxide/dye hybrids have been prepared by a simple one-step solution process.In addition,the phenylalanine-zinc/dye hybrid bundles with novel structures and new optical properties have been synthesized by introducing amino acid into hybrid system.The functionalities of materials not only depend on their compositions,but also on the shapes and microstructures.1.Cobalt carbonate crystals with different shapes,such as microspheres,flowers, dumbbells,peanuts,rods ere,have been successfully synthesized by the hydrothermal reaction of cobalt acetate and ammonium hydrogen carbonate at 160℃,which are achieved via tuning the volume ratios of the mixed solvents of water and ethanol(or glycerol).The growth and nucleation mechanism of CoCO₃ crystals in the mixtures of water and ethanol can be illuminated by dissolution-renucleation process and aggregate-based mechanism;while the shape transitions of the particles in the water-glycerol system are well consistent with the "rod-dumbbell-sphere" morphogenesis mechanism.The nanoporous cobalt oxides with unchanged shapes can be obtained by the calcination of CoCO₃ precursors.The nanoporous Co₃O₄ particles show sensitive response and reversibility in sensing performances.2.The shapes and sizes of dye acid green 27(AG27) can be controlled via tuning the volume ratios of ethanol(or methanol) and water in the mixed solvents by recrystallization method at 80℃.Rodlike and shuttlelike AG27 crystals can be selectively synthesized.The XRD analyses reveal the periodic structures of the organic crystals.The growth mechanism is investigated from the viewpoint of thermodynamics and kinetics.3.Colorful ZnO/dye hybrid functional materials with new optical properties have been synthesized through self-assembly process.It is found that various dyes can be incorporated into ZnO and form hybrids with unique morphologies and novel properties by the similar method.A synergetic-template effect,generated by the interaction between surfactants and dye molecules through ionic self-assembly,has been proposed.4.The raft-like phenylalanine-zinc complexes and phenylalanine-zinc/dye hybrid bundles with new optical properties have been fabricated from the water-ethanol mixed solvents.A principle of classical electric line in the mineralization process directing alignment of phenylalanine-zinc/dye bundles is illuminated.Systematically,dye molecules play crucial roles in the formation of functional inorganic-organic hybrid materials.They are the controller of shapes and properties of the hybrid composites,as well as the inclusive components.