表面修饰二氧化钛纳米粒子的结构表征及形成机理

利用溶胶 凝胶法在混合溶剂中制备了硬脂酸表面修饰TiO2纳米粒子，对所合成的纳米粒子通过FTIR、XPS、XRD和TEM对其结构进行表征.结果确证了表面有机修饰层的存在，并且是羧酸根与无机内核以双齿配位形式结合；无机纳米内核的结晶度很低，但是可以确定为锐钛矿成分，平均粒径约为6～8 nm.提出了表面修饰纳米粒子的形成机理，认为在体系中硬脂酸和水之间发生竞争反应，其过程类似于聚合 阻聚反应，最后给出了硬脂酸表面修饰TiO2纳米粒子的结构模型.

StructuralCharacterization and Formation Mechanism of Surface

Surface modified titanium dioxide nanoparticles are synthesized in organic media via sol gel method. The chemical structure of nanoparticles as well as its formation mechanism are discussed on the basis of Fourier transform infrared spectroscopy (FT IR), X ray photoelectron spectroscopy (XPS), transmission electron microscopy(TEM), and X ray diffraction (XRD). The results confirm the existence of organic layer, which was connected with the inorganic nuclei by bidentate coordination.The average diameter of nanoparticles is about 6 8 nm. Although poor crystallinity obtained, the anatase phase of TiO2 could be inferred.The existence of organic ligands would greatly impact the nucleation and surface coordination of nanoparticles. The formation mechanism is postulated as a competitive reaction between polymerization and inhibition processes. Finally, the structural model for organo capped TiO2 nanoparticles is proposed.