We study the frictional response of water-lubricated gold electrodes subject to an electrostatic potential difference using molecular dynamics simulations. Contrary to previous studies on electrotunable lubrication that were carried out by fixing the charges, our simulations keep electrodes at fixed electrostatic potential using a variable charge method. For pure water and NaCl solutions, viscosity is independent of the polarization of the electrodes, but wall slip depends on the potential difference. Our findings are in agreement with previous analytical theories of how wall slip is affected by interatomic interactions. The simulations shed light on the role of electrode polarization for wall slip and illustrate a mechanism for controlling friction and nanoscale flow in simple aqueous lubricants.

我们使用分子动力学模拟研究了水润滑金电极在静电势差作用下的摩擦响应。与以前通过固定电荷进行的电可调润滑研究相反，我们的模拟使用可变电荷方法将电极保持在固定的静电势下。对于纯水和NaCl溶液，粘度与电极的极化无关，但壁滑取决于电位差。我们的发现与先前关于壁滑如何受原子间相互作用影响的分析理论相一致。该模拟揭示了电极极化对壁滑的作用，并说明了一种在简单的水性润滑剂中控制摩擦和纳米级流动的机制。