Molecular simulations on the hydration and underwater oleophobicity of zwitterionic self-assembled monolayers
Molecular simulations on the hydration and underwater oleophobicity of zwitterionic self-assembled monolayers
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两性离子自组装单分子层水合和水下疏油性的分子模拟
DOI：
10.1002/aic.17103
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发表时间：
2020-11-02
期刊：
影响因子：
3.7
通讯作者：
Zhou, Jian
中科院分区：
文献类型：
--
作者：
Chen, Zheng;Liao, Mingrui;Zhou, Jian
两性离子材料因其通过静电相互作用产生的强水合作用而在水下超疏油应用中受到越来越多的关注。本文采用分子动力学模拟的方法研究了巯基甜菜碱端自组装单层膜（SB- sam）的水合性能和水下疏油性能。模拟结果表明：sb - sam的水化与CSL呈正相关；随着CSL的增加，水下疏油性先增强后减弱，在CSL = 3时达到最佳；油滴在sb - sam表面的粘附力与其接触角呈负相关，在CSL = 3时达到最小值。此外，NaCl的加入可以减弱SB分子在正阴离子基相互作用下的自缔合，从而促进水合作用，增强SB- sam的水下疏油性。这些结果将有助于设计新型两性离子基材料用于防污和油水分离。
Zwitterionic materials have attracted increasing attentions in the underwater super-oleophobic applications for its strong hydration via electrostatic interactions. Herein, molecular dynamics simulations were used to investigate the hydration and underwater oleophobicity of sulfobetaine-terminated self-assembled monolayers (SB-SAMs) with different carbon spacer lengths (CSL) between oppositely charged groups of SB molecules. Simulation results show that the hydration of SB-SAMs is positively dependent on CSL; the underwater oleophobicity is strengthened and then weakened with the increase of CSL, reaching optimal performance when CSL = 3; adhesion force of oil droplet on SB-SAMs is inversely correlated with their contact angles, reaching the minimum value when CSL = 3. Moreover, the addition of NaCl can weaken the self-association of SB molecules resulted from interactions between cationic and anionic groups, which promotes hydration and enhances underwater oleophobicity of SB-SAMs. These results will benefit for the design of novel zwitterion-based materials for anti-fouling and oil-water separation applications.