电场对FOTS自组装分子膜/SiO_2界面作用特性的影响

Interfacial contact characteristics between FOTS SAMs and SiO_2 under electric field

为研究电场对自组装分子膜摩擦学特性的影响,采用分子动力学模拟软件Materials Studio5.0计算不同电场强度和作用方向下FOTS自组装分子膜与SiO2基底的界面结合能.结果表明:当电场强度小于3.0×108V/m时,施加正负方向电场,界面结合能均增大,而施加正电场的界面结合能增大较多,但在正负方向电场作用下界面结合能随着场强的增加变化幅度较小.对FOTS与SiO2基底相互作用能的分析得知,影响体系结合能的主要因素是两者之间的范德华力,其中色散力起主要作用.

Molecular dynamics simulation software package Materials Studio5.0 was used to calculate the binding energy between self-assembled monolayer FOTS and SiO2 substrate at different electric field strengths and directions.Results show that the interface binding energy both increases whether the applied electric field is positive or negative when the electric field strength is less than 3.0×108 V/m,while the interface binding energy for the positive electric field increases more.But the binding energy of the interface changes a little when both the positive and negative electric field strengths increase.At the same time, the interaction energy between FOTS and SiO2 substrate was analyzed,and the results show that the key influencing foctor for the binding property is the Van der Waals force in the system,and the contribution of dispersive force in van der Waals force is the most important one.