当前位置: X-MOL 学术J. Phys. Chem. B › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Adsorption and Self-Assembly of Surfactants on Metal–Water Interfaces
The Journal of Physical Chemistry B ( IF 2.8 ) Pub Date : 2017-11-07 00:00:00 , DOI: 10.1021/acs.jpcb.7b09297
Xueying Ko 1 , Sumit Sharma 1
Affiliation  

Modifying properties of metal–water interfaces via adsorption of surfactants has applications in electrochemistry and catalysis. We report molecular simulations of adsorption of surfactant molecules on metal surfaces wherein we systematically vary the strength of hydrophobic interaction between surfactant tails, as well as the size of the surfactants’ polar head group. A surfactant molecule is represented by a linear, bead–spring model with a polar “head” bead and a chain of hydrophobic “tail” beads. A smooth surface, strongly attractive to the polar beads, represents the metal surface. Our main findings are that (1) hydrophobic interactions between adsorbed molecules promote adsorption and self-assembly and (2) the morphology of the adsorbed layer is governed by the geometry of the molecules. When the size of the polar bead is the same as that of the hydrophobic beads, an adsorbed self-assembled monolayer (SAM) is formed. When the polar bead is larger than the hydrophobic beads, cylindrical micelles are formed in the bulk and the adsorbed phase. For the adsorbed SAM, the layer is patchy, with a significant fraction of the molecules adsorbed with their polar beads pointing away from the surface. These results corroborate with experimental observations and provide new insights into the molecular nature of adsorbed layers.

中文翻译:

表面活性剂在金属-水界面上的吸附和自组装

通过吸附表面活性剂来改变金属-水界面的性质已在电化学和催化中得到应用。我们报告了金属表面活性剂分子吸附的分子模拟,其中我们系统地改变了表面活性剂尾部之间的疏水相互作用的强度以及表面活性剂极性头基团的大小。表面活性剂分子由具有极性“头”珠和疏水“尾”珠链的线性珠-弹簧模型表示。光滑表面对金属珠具有极强的吸引力,极易吸引极性珠子。我们的主要发现是:(1)吸附分子之间的疏水相互作用促进了吸附和自组装,(2)吸附层的形态受分子的几何形状支配。当极性珠的尺寸与疏水珠的尺寸相同时,形成吸附的自组装单层(SAM)。当极性珠大于疏水珠时,在本体和吸附相中形成圆柱形胶束。对于吸附的SAM,该层是不规则的,吸附的大部分分子的极性珠指向远离表面。这些结果与实验观察结果相符,并为吸附层的分子性质提供了新的见解。大部分的分子被吸附,其极性珠子指向远离表面的方向。这些结果与实验观察结果相符,并为吸附层的分子性质提供了新的见解。大部分的分子被吸附,其极性珠子指向远离表面的方向。这些结果与实验观察结果相符,并为吸附层的分子性质提供了新的见解。
更新日期:2017-11-08
down
wechat
bug