Simulation Study of the Silicon Oxide and Water Interface
Simulation Study of the Silicon Oxide and Water Interface
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DOI：
10.1166/jctn.2010.1647
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发表时间：
2010-12-01
影响因子：
--
通讯作者：
Grest, Gary S.
中科院分区：
文献类型：
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作者：
Lorenz, Christian D.;Tsige, Mesfin;Grest, Gary S.
经典和从头算分子动力学模拟进行了研究三种不同的二氧化硅基板：α-石英，β-方石英，和无定形二氧化硅界面附近的水的结构特性。对于经典的模拟，OPLSTTIP 3 P和COMPASS/SPCE力场都被用来研究二氧化硅/水界面。量子模拟使用VASP平面波赝势代码，该代码通过使用Perdew和Wang的广义梯度近似（GGA）明确地处理系统中的价电子，并通过范德比尔特超软赝势方案表示内核电子。确定了水分子在界面处的取向，并且通常经典力场和量子模拟都表明，在界面附近，水分子取向为使得至少一个氢比水分子的氧更接近二氧化硅。测定了水分子与其他水分子以及与二氧化硅表面上的硅醇（Si-O-H）基团的氢键网络。水分子与硅烷醇基团形成大量氢键，导致与本体中的水分子相比，界面附近的水的流动性降低。
Classical and ab-initio molecular dynamics simulations were carried out to study the structural properties of water near a silica interface for three different silica substrates: alpha-quartz, beta-cristobalite, and amorphous silica. For the classical simulations, both the OPLSTTIP3P and the COMPASS/SPCE force fields were used to study the silica/water interface. The quantum simulations used the VASP plane-wave pseudopotential code that treats the valence electrons in the system explicitly by using the generalized gradient approximation (GGA) of Perdew and Wang and represents the inner core electrons by the Vanderbilt ultrasoft pseudopotential scheme. The orientation of the water molecules at the interface was determined and in general both of the classical force fields and the quantum simulations show that near the interface the water molecules are oriented such that at least one of the hydrogens are nearer the silica than the oxygen of the water molecule. The hydrogen bond network of water molecules with other water molecules and with the silanol (Si-O-H) groups on the silica surface was determined. The water molecules form a significant number of hydrogen bonds with the silanol groups resulting in a reduction in mobility of the water near the interface as compared to water molecules in the bulk.