Abstract With methyltriethoxysilane as hydrophobic precursors and aluminum isopropoxide as the aluminum source, the Al2O3/SiO2 sols and their gel materials were prepared. The effects of aluminum content (nAl) on the viscosity (η), density (ρ), reaction rate constant (k), Gibbs energies of activation for viscous flow (ΔG*), particle size of Al2O3/SiO2 sols were studied. And the high temperature calcined materials were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). The results show that, with the increase of nAl, the η, n and ΔG* values of the Al2O3/SiO2 sols decrease while the k and ρ values and average particle sizes increase. There is strong intermolecular interaction between the Al2O3 and SiO2 sol molecules. The Al-O-Si bond exists in the Al2O3/SiO2 materials before and after calcination at 350 °C. Calcination at 350 °C in N2 atmosphere can change the phase structure of Al2O3/SiO2 sample greatly, which can make the γ-AlOOH in the Al2O3/SiO2 gel material convert to γ-Al2O3 through dehydration.

中文翻译：

---

铝掺杂对甲基改性SiO2溶胶性能和微观结构的影响

摘要 以甲基三乙氧基硅烷为疏水前驱体，异丙醇铝为铝源，制备了Al2O3/SiO2溶胶及其凝胶材料。研究了铝含量 (nAl) 对粘度 (η)、密度 (ρ)、反应速率常数 (k)、粘性流动的吉布斯活化能 (ΔG*)、Al2O3/SiO2 溶胶粒径的影响。并通过X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）和扫描电子显微镜（SEM）对高温煅烧材料进行了表征。结果表明，随着nAl的增加，Al2O3/SiO2溶胶的η、n和ΔG*值减小，而k、ρ值和平均粒径增大。Al2O3 和 SiO2 溶胶分子之间有很强的分子间相互作用。在 350 °C 煅烧前后，Al2O3/SiO2 材料中存在 Al-O-Si 键。在 N2 气氛中 350 ℃煅烧可以极大地改变 Al2O3/SiO2 样品的相结构，使 Al2O3/SiO2 凝胶材料中的 γ-AlOOH 通过脱水转化为 γ-Al2O3。