Time evolution studies of the H2O/quartz interface using sum frequency generation, atomic force microscopy, and molecular dynamics
Time evolution studies of the H2O/quartz interface using sum frequency generation, atomic force microscopy, and molecular dynamics
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DOI：
10.1021/la048639u
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发表时间：
2004-11-23
期刊：
影响因子：
3.9
通讯作者：
Shultz, MJ
中科院分区：
文献类型：
--
作者：
Li, I;Bandara, J;Shultz, MJ
许多固体表面（例如石英/水）的界面研究都假设标准清洁程序可重现地再生表面。在报告的工作中，两种表面特异性技术，和频发生（SFG）光谱和原子力显微镜的结果表明，长时间暴露于纳米纯水和pH 10 NaOH的影响是明显不同的。结合实验数据，分子力学是用来关联的SFG光谱频率的表面结合水分子的氢伸缩振动。结果发现，浸泡在水中17天后，水分子渗透到SiO2基质中产生溶胀和无定形层;很可能是从抛光过程中断裂的Si-O键作为水合和溶胀的成核位点。界面水层中引入的无序通过3450 cm（-1）处的弱氢键SFG峰的强度上升来检测。在pH值为10的NaOH浸泡过的石英盘中，3450 cm（-1）的优势不存在，这表明水中的强氢键网络保持完整。
Many interfacial studies on solid surfaces, for example, quartz/water, assume that a standard cleaning procedure regenerates the surface reproducibly. In the reported work, the results of two surface specific techniques, sum frequency generation (SFG) spectroscopy and atomic force microscopy, show that the effects of prolonged exposure to Nanopure water and to pH 10 NaOH are distinctly different. In conjunction with the experimental data, molecular mechanics is used to correlate the SFG spectral frequencies to the hydrogen stretching vibrations of the surface-bound water molecules. It is found that after 17 days of soaking in water, water molecules penetrate into the SiO2 matrix to produce a swollen and amorphous layer; it is likely that broken Si-O bonds from the polishing process serve as nucleation sites for hydration and swelling. Disorder introduced in the interfacial water layer is detected by the rising intensity of the weakly hydrogen-bonded SFG peak at 3450 cm(-1). Dominance of the 3450 cm(-1) is absent in a pH 10, NaOH-soaked quartz disk, indicating that the strong hydrogen-bonded network in water remains intact.