Free energetics of carbon nanotube association in aqueous inorganic NaI salt solutions: Temperature effects using all-atom molecular dynamics simulations.
Free energetics of carbon nanotube association in aqueous inorganic NaI salt solutions: Temperature effects using all-atom molecular dynamics simulations.
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DOI：
10.1002/jcc.23906
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发表时间：
2015-06-15
影响因子：
3
通讯作者：
Patel, Sandeep
中科院分区：
文献类型：
--
作者：
Ou, Shu-Ching;Cui, Di;Wezowicz, Matthew;Taufer, Michela;Patel, Sandeep
关键词：
在这项研究中，我们研究的自由能的纳米管协会的温度依赖性，通过使用GPU启用的全原子分子动力学模拟（FEN ZI）与两个（10，10）单壁碳纳米管在3 m碘化钠水溶液。结果表明，自由能，焓变和熵变的缔合过程都减少在高温下，与以前的调查使用其他疏水。通过将自由能分解为单个组分，我们发现溶剂贡献（包括水、阴离子和阳离子贡献）与相应物种的空间分布相关，并明显受温度的影响。我们研究了溶剂在不同区域的空间分布和结构：管间，管内和本体溶剂。通过计算粗颗粒管-溶剂界面的涨落，我们发现管-水界面的涨落具有最强的温度依赖性。通过采取离子是一种溶剂样介质在没有水的情况下，管阴离子界面波动也表现出类似的，但较弱的依赖于温度，而管阳离子界面波动显示一般没有依赖性。这些特点进行了讨论，通过其相应的溶剂化壳相对于纳米管表面的延展性。同时计算了水分子排列的氢键分布和四面体度，比较了溶剂本体和管间区域的溶剂结构。疏水性限制诱导在管间区域中的相对较低的浓度环境，因此导致取决于管分离的不同的管间溶剂结构。这项研究是相关的疏水相互作用的持续话语（因为它们通常会影响生物学，生物化学和材料科学和软凝聚态研究中的一大类现象），和疏水性的解释替代但平行的签名，如界面波动，去湿转换，并增强波动概率接口。
In this study we examine the temperature dependence of free energetics of nanotube association by using GPU-enabled all-atom molecular dynamics simulations (FEN ZI) with two (10,10) single-walled carbon nanotubes in 3 m NaI aqueous salt solution. Results suggest that the free energy, enthalpy and entropy changes for the association process are all reduced at the high temperature, in agreement with previous investigations using other hydrophobes. Via the decomposition of free energy into individual components, we found that solvent contribution (including water, anion and cation contributions) is correlated with the spatial distribution of the corresponding species and is influenced distinctly by the temperature. We studied the spatial distribution and the structure of the solvent in different regions: intertube, intra-tube and the bulk solvent. By calculating the fluctuation of coarse-grained tube-solvent surfaces, we found that tube-water interfacial fluctuation exhibits the strongest temperature dependence. By taking ions to be a solvent-like medium in the absence of water, tube-anion interfacial fluctuation also shows similar but weaker dependence on temperature, while tube-cation interfacial fluctuation shows no dependence in general. These characteristics are discussed via the malleability of their corresponding solvation shells relative to the nanotube surface. Hydrogen bonding profiles and tetrahedrality of water arrangement are also computed to compare the structure of solvent in the solvent bulk and intertube region. The hydrophobic confinement induces a relatively lower concentration environment in the intertube region, therefore causing different intertube solvent structures which depend on the tube separation. This study is relevant in the continuing discourse on hydrophobic interactions (as they impact generally a broad class of phenomena in biology, biochemistry, and materials science and soft condensed matter research), and interpretations of hydrophobicity in terms of alternative but parallel signatures such as interfacial fluctuations, dewetting transitions, and enhanced fluctuation probabilities at interfaces.
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影响因子：
3.3
作者：
Corradini, D.;Rovere, M.;Gallo, P.
通讯作者：
Gallo, P.
DOI：
10.1039/c1cp20839j
发表时间：
2012-02-14
期刊：
Physical chemistry chemical physics : PCCP
影响因子：
--
作者：
Bauer BA;Ou S;Patel S
通讯作者：
Patel S
影响因子：
2.8
作者：
Bauer, Brad A.;Ou, Shuching;Patel, Sandeep
通讯作者：
Patel, Sandeep
影响因子：
3.3
作者：
Bauer, Brad A.;Patel, Sandeep
通讯作者：
Patel, Sandeep
影响因子：
2.4
作者：
Bauer, Brad A.;Ou, Shuching;Siva, Karthik
通讯作者：
Siva, Karthik