Block Copolymer (ps-b-paa) / Inorganic Hybrid Materials And Applications

With the continuous development of science, Materials science from single polymer material changes to the interdisciplinary, organic-inorganic hybrid materials of scientific development has become one of the important directions. The inorganic-organic hybrid materials are used widely in electricity, magnetics, and optics fields and so on, because of its interesting optical, magnetic, catalytic and thermal steady properties. Therefore, to seek such new materials of excellent performance will be one of the key research subjects in the coming period on the field of materials subject. In this thesis, our research is mainly focused on the following three parts:1. Silver nanoparticles were synthesized by using amphiphilic block copolymer PS-b-PAA based on the flexibility of the copolymer chains and the complex effect of -COOH in the poly(crylic acid) with Ag⁺ and Ag under ultrasonic irradiation. The product was characterized by Atomic Force Microscopy (AFM), Fourier Transfer Infrared Spectrometer (FT-IR), Transmission Electron Microscope (TEM), UV-Vis spectrum and Thermal Gravity Analysis (TGA). The FT-IR results revealed that the backbone of the PS-b-PAA block copolymer was not be cleavage during the synthesis of the silver nanoparticles under ultrasonic irradiation. The TEM results revealed that the size of the resulting silver nanoparticles prepared basing on the copolymer was strongly dependent on the initial concentration of the silver ion solution and the copolymer. Low initial silver ion concentration allowed for yielding silver nanoparticles with a small size and the size of the silver nanoparticles increased with the concentration of the silver ion solution increasing. And that the silver nanoparticles decreased with the M_n of the copolymer increasing.2. Using the block copolymers as a protective agent, the single crystals of silver nanorods and highly ordered dendritic supramolecular silver nanomaterials were prepared under low-intensity ultrasound irradiation at room temperature. The electronic diffraction pattern indicated that the silver nanorods are single crystal. The shape of the silver nanocrystal grows from stick to dendritic. The concentration of silver nitrate and copolymer play an important role in formation and growth process of the silver nanocrystal. These different silver nanomaterials possibly have important application in catalysis applications. This method can be extended to prepare the new type of nano-structure of other precious metals.3. The idea of preparing the surface of Fe₃O₄ layer pre-adsorbed on the copolymer via layer by layer self-assembly approach receives special relevance in enzyme technology. The copolymer PS-b-PAA/Fe₃O₄ support presents a very simple, mild, and time-saving process for enzyme immobilization. We discussed the storing stability, reusability and kinetic property of the free enzyme and the Immobilized enzyme. The most significant advantages of the Immobilized enzyme is the long-term storing stability. And immobilized enzymes have good pH stability in a wide pH range, maintaining a high level of enzyme activity. The immobilized enzyme which have good stability reduced the cost of the expensive enzyme and opened up a new field of the catalytic technology. These particles, premodified with the layer of magnetic nanoparticles to impart a magnetic property were repeatedly used as catalysts following their rapid and easy separation with a magnet.