Supercritical synthesis of organic-monolayer modified nanocrystals and organic-inorganic hybrid nanomaterials

(1)水热反应机理与动力学分析了有机分子与金属离子之间的化学反应速率和平衡常数。结果表明：1)有机分子和金属离子以单相形式存在，2)金属氧化物纳米粒子的成核是由于溶解度降低所致，3)金属氧化物纳米粒子的表面封顶导致了纳米粒子的生长速度，4)合成了表面修饰的金属氧化物纳米粒子。我们还发现，表面修饰反应受控于金属氧化物纳米粒子的表面电势和表面改性剂的电离之间的平衡。(2)表面修饰金属氧化物纳米粒子的超临界合成研究进展。我们开展了表面修饰金属氧化物纳米颗粒的超临界合成，以制备表面修饰的金属氧化物纳米颗粒。我们将纳米粒子的制备步骤和表面修饰步骤分开，以优化表面修饰的程度、表面修饰后的金属氧化物纳米粒子的大小和形状。阐述了反应物在超临界水中的混合方式，成功地制备出了较小的纳米颗粒。(3)有机-无机相互作用的表征我们评价了有机分子与金属氧化物纳米颗粒的键合机理。用热重法测定了成键能、距离和覆盖度。用动态光散射法表征表面修饰的金属氧化物纳米粒子的分散程度。(4)有机-无机杂化材料的合成我们对合成的杂化纳米材料进行了表征。并研究了尺寸和表面修饰对金属氧化物纳米粒子性能的影响。在此基础上，提出了杂化纳米材料的指导原则。

(1) Mechanism and kinetics of hydrothermal reaction We analyzed the rate and equilibrium constant of chemical reaction between organic molecules and metal ions. The results are 1) Organic molecules and metal ions exist in the single phase, 2) Nucleation of metal oxide nanoparticle occurs due to reduced solubility, 3) Capping of the surface of metal oxide nanoparticles results in the growth rate of the nanoparticles, and 4) Surface-modified metal oxide nanoparticles are synthesized. We also found that the reaction of surface modification was controlled by the balance between the surface potential of metal oxide nanoparticles and the ionization of surface modifiers.(2) Development of supercritical synthesis of surface-modified metal oxide nanoparticles. We developed the supercritical synthesis of surface-modified metal oxide nanoparticles to produce surface-modified metal oxide nanoparticles. We separated the nanoparticle production step and the surface-modification step to optimize the degree of surface modification, size and shape of surface-modified metal oxide nanoparticles. We also elaborated the way of mixing the reactants supercritical water and successfully produced smaller nanoparticles.(3) Characterization of organic-inorganic interaction We evaluated the bonding mechanism of organic molecule and metal oxide nanoparticles. Thermogravimetry is used to evaluate the bonding energy, distance and coverage. The dynamics light scattering measurement was used to elucidate the degree of dispersion of surface-modified metal oxide nanoparticles.(4) Synthesis of organic-inorganic hybrid material We characterized the synthesized hybrid nanomaterials. and studied the effect of size and surface modification on the properties of metal oxide nanoparticles. Based on the above discussion, we proposed the guiding principles of hybrid-nanomaterials.