分子动力学模拟多巴在自组装膜上的黏附性

发布时间：2019-08-17 16:33

【摘要】：为了更好地理解贻贝在表面的黏附机理,实现水下胶黏,采用分子动力学方法研究了多巴在自组装膜上的黏附性:采用伞形取样和加权柱状图分析方法计算了多巴在不同自组装膜表面的黏附自由能,使用拉伸分子动力学模拟研究了多巴在不同自组装膜表面上黏附后的脱附力.结果表明,多巴在带负电的羧基自组装膜上的黏附能比在带正电的氨基自组装膜上的大,多巴更容易黏附到带负电表面;多巴在带电表面的黏附能比未带电表面的黏附能更强,表明在带电表面黏附更稳定.进一步分析了多巴在不同表面的取向分布,发现多巴与不同表面相互作用的方式不同:与疏水表面主要通过苯环相互作用;与亲水表面主要通过羟基相互作用;与负电表面主要通过氨基相互作用;与正电表面主要通过羧基相互作用.通过模拟比较了多巴在不同自组装膜上的脱附力,发现多巴在带电表面的脱附力比在未带电表面的大,与黏附能的趋势一致.对比4种非带电表面的脱附力,发现多巴在疏水性甲基自组装膜表面的脱附力最大,黏附更稳定,随着表面疏水性的增加,脱附力增大,黏附稳定性增强.本工作可为研发新型水下胶黏剂提供理论指导.
[Abstract]:In order to better understand the adhesion mechanism of mussel on the surface and realize the adhesion of mussel to underwater adhesive, the adhesion of dopa on the self-assembled monolayers was studied by molecular dynamics method. The adhesion free energy of dopa on different self-assembled monolayers was calculated by umbrella sampling and weighted histogram analysis, and the desorption force of dopa on different self-assembled monolayers was studied by tensile molecular dynamics simulation. The results showed that the adhesion energy of dopa on the negatively charged carboxy self-assembled monolayers was larger than that on the positively charged amino self-assembled membranes, and the dopa adhesion energy on the charged surface was stronger than that on the uncharged surface, indicating that the adhesion energy on the charged surface was more stable than that on the charged surface. The orientation distribution of dopa on different surfaces is further analyzed, and it is found that the interaction between dopa and different surfaces is different: the interaction with hydrophobic surface is mainly through benzene ring; with hydrophilic surface is mainly through hydroxyl group interaction; with negative electric surface is mainly through amino group interaction; and with positive surface is mainly through carboxy group interaction. By simulating and comparing the desorption force of dopa on different self-assembled monolayers, it is found that the desorption force of dopa on the charged surface is larger than that on the uncharged surface, which is consistent with the trend of adhesion energy. By comparing the desorption force of four kinds of uncharged surfaces, it was found that the desorption force of dopa on the surface of hydrophobic methyl self-assembled monolayers was the largest and the adhesion was more stable. With the increase of surface hydrophobicity, the desorption force increased and the adhesion stability increased. This work can provide theoretical guidance for the research and development of new underwater adhesive.
【作者单位】：华南理工大学化学与化工学院广东省绿色化学产品技术重点实验室;
【基金】：国家自然科学基金(批准号:21376089,91334202) 国家重点基础研究发展计划(批准号:2013CB733504) 广东省自然科学基金(批准号:2014A030312007) 中央高校基本科研业务费项目(批准号:SCUT-2015ZP033)资助~~
【分类号】：O647.4

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