Soft Solution Process-Based Synthesis And Property Research Of Organic-Inorganic Nano-Composites

With the development of nanotechnology, organic-inorganic composites have been attracting more and more attendion. Organic-inorganic composites with well-defined structure and morphology of nano-scale are very interesting and promising materials due to their numerous novel properties and applications in a wide range of fields. The preparation of organic-inorganic nano compostites in a form of emulsion is much preferable because of its easy processability. In this dissertation, three organic-inorganic composites have been prepared through a soft solution process.The main results can be briefly summarized as follows:1. Au/aminosilica nanocomposite spheres have been synthesized via a simple one-pot route using HAuCl4and N-(3-Trimethoxysillylpropyl)-ethylenediamine as starting materials. The obtained functional nanocomposites as non-viral carriers for gene delivery show higher transfection efficiency and lower cytotoxicity in human umbilical vein endothelial cells than commercial Lipofectamine2000. From these results, it could be expected to develop alternative new vectors for gene delivery. In addition, Au/aminosilica particles are biocompatible, thus the as-prepared hybrid functional materials are promising in gene delivery and drug carrier.2. A sheaflike Zn(Ⅱ)-2,2’-biquinoline-4,4’-dicarboxylic acid disodium salt (Zn-BCA) coordination polymer has been successfully synthesized through a simple and mild one-step process in aqueous solution at room temperature. The effects of reactant molar ratio, temperature and reaction time on the morphology of the coordination polymer have also been examined. It was found that the Zn-BCA coordination polymer shows a greatly enhanced blue photoluminescence (PL) emission compared with Zn-free BCA.3. Upgraded metal cation-mediated bridged hybrid mesoscopic material (MBH-S) with photoluminescence (PL) property is easily obtained in aqueous solution at room temperature and has a remarkably high anion-exchange capacity. The hybrid material exhibits a PL emission peaking at444nm under the excitation of370nm ultraviolet (UV) light. The PL intensity decreases and the PL spectrum shows a right shift after appropriate thermal treatment at180℃. This material with a structural origin of PL is an intrinsic phosphor that do not contain activator ions. An anion molecule of rhodamine B (RhB) with strong yellow luminescence can be exchanged into MBH-S, forming composite solid of MBH-S-RhB with very strong luminescence under the excitation of UV light (λexc=370nm). The PL of the composite can be tuned by changing the time of thermal treatment and the amount of RhB exchanged into MBH-S. Under the same excitation UV light, the composite shows a very white light emission after MBH-S is heated at180℃for6h and250μL of1mM aqueous solution of RhB is exchanged into it.