论文标题
用功能化烷基硫醇钝化的金纳米颗粒：无限稀释极限中溶剂化的模拟
Gold Nanoparticles Passivated with Functionalized Alkylthiols: Simulations of Solvation in the Infinite Dilution Limit
论文作者
论文摘要
Solvation of gold nanoparticles passivated with end group functionalized alkylthiols, namely CH$_3$, NH$_2$ or COOH is studied in solvents of varying degrees of repulsion-dispersion and electrostatic interactions ranging from strongly polar SPC/E water to modified hybrid water models, where the Lennard-Jones contribution to the potential energy is enhanced relative to SPC/E完全非极性，脱烷。使用纳米颗粒 - 溶剂对相关函数和四面体阶阶参数来监测纳米颗粒周围溶剂重组的影响。配体壳内部的溶剂穿透最大，脱烷最大，表明与其他溶剂相比，脱烷的溶质 - 溶剂相互作用更好。与本研究中使用的其他纳米颗粒相比，COOH端组功能化的纳米颗粒更加打破了水分子的四面体结构。使用径向密度谱（RDP），回旋半径（$ r_g $）和配体不对称参数（$ \langleΔ\ rangle $）来监测配体重组及其对溶剂化的影响。 RDP和$ r_g $值在脱烷中显示出明显的配体拉伸，这也与$ \langleδ\ rangle $一致。所有纳米颗粒的配体壳各向异性在SPC/E水中最大，脱烷中最小。在真空，SPC/E水和H3.00修饰的混合水中计算了两个相同末端官能化的纳米颗粒之间平均力（$ v_ {pmf}（r）$）的各向同性潜力，这始终显示出吸引人的井深。还检查了距离依赖性波动驱动的各向异性。突出了从水分散体中的钝化金纳米颗粒以及计算量对配体和溶剂化学的依赖性的含义。
Solvation of gold nanoparticles passivated with end group functionalized alkylthiols, namely CH$_3$, NH$_2$ or COOH is studied in solvents of varying degrees of repulsion-dispersion and electrostatic interactions ranging from strongly polar SPC/E water to modified hybrid water models, where the Lennard-Jones contribution to the potential energy is enhanced relative to SPC/E to completely non-polar, decane. The effects due to solvent reorganization around the nanoparticle as a function of the ligand and solvent chemistry are monitored using the nanoparticle-solvent pair correlation functions and tetrahedral order parameter. The solvent penetration inside the ligand shell is maximum for decane, indicating better solute-solvent interaction in decane compared to other solvents. The COOH end group functionalized nanoparticle breaks the tetrahedral structure of water molecules more as compared to other nanoparticles used in this study. The ligand reorganization and its effect on solvation are monitored using radial density profiles (RDPs), radius of gyration ($R_g$) and ligand asymmetry parameter ($\langle Δ\rangle$). RDP and $R_g$ values show significant stretching of ligands in decane than in model waters, which is also consistent with $\langle Δ\rangle$. The ligand shell anisotropy for all nanoparticles is maximum in SPC/E water and minimum in decane. The isotropic potential of mean force ($V_{PMF}(r)$) between two identical end group functionalized nanoparticles have been calculated in vacuum, SPC/E water and H3.00 modified hybrid water, which consistently shows attractive well depth. Distance-dependent fluctuation driven anisotropy has also been examined. The implications for self-assembly of passivated gold nanoparticles from aqueous dispersions as well as the dependence of calculated quantities on ligand and solvent chemistry are highlighted.
