Journal of Colloid and Interface Science ( IF 9.4 ) Pub Date : 2021-09-14 , DOI: 10.1016/j.jcis.2021.09.051 Hubao A 1 , Zhibing Yang 1 , Ran Hu 1 , Yi-Feng Chen 1
|
Hypothesis
The imbibition dynamics is controlled by energy dissipation mechanisms and influenced by asymmetric wettability in a nanochannel. We hypothesize that the imbibition dynamics can be described by a combined model of the Lucas–Washburn equation and the Cox-Voinov law considering velocity-dependent contact angles.
Methods
Molecular dynamics simulations are utilized to investigate the imbibition dynamics. A wide range of wetting conditions is achieved via adjusting the liquid–solid interaction parameters, and the spontaneous imbibition processes are quantified and compared.
Findings
The critical condition for the occurrence of spontaneous imbibition is analyzed from a surface energy perspective. The analyses of energy conversion and dissipation indicate that the viscous dissipation is dominant during spontaneous imbibition. The classical Lucas-Washburn equation is modified with the Cox–Voinov law considering the effect of the dynamic contact angle and an effective equilibrium contact angle. We show that the proposed theory well captures the imbibition dynamics embodied in the growth of imbibition length as well as the transient interface shape and velocity for both the symmetric and asymmetric wetting conditions. In nanochannels with asymmetric wettability, the imbibition length difference between the sidewalls and interface oscillations increases with wetting disparity. Our findings deepen the understanding of imbibition dynamics on the nanoscale, and provide a theoretical reference for relevant applications.
中文翻译：
能量耗散和不对称润湿性在纳米通道自吸动力学中的作用
假设
渗吸动力学受能量耗散机制控制，并受纳米通道中不对称润湿性的影响。我们假设渗吸动力学可以通过 Lucas-Washburn 方程和考虑速度相关接触角的 Cox-Voinov 定律的组合模型来描述。
方法
分子动力学模拟被用来研究渗吸动力学。通过调整液固相互作用参数实现了广泛的润湿条件，并对自吸过程进行了量化和比较。
发现
从表面能的角度分析了自吸发生的临界条件。能量转换和耗散的分析表明，在自吸过程中粘性耗散占主导地位。考虑到动态接触角和有效平衡接触角的影响，经典的 Lucas-Washburn 方程用 Cox-Voinov 定律进行了修改。我们表明，所提出的理论很好地捕捉了渗入长度的增长以及对称和非对称润湿条件下的瞬态界面形状和速度所体现的渗入动力学。在具有非对称润湿性的纳米通道中，侧壁和界面振荡之间的吸入长度差异随着润湿差异而增加。
京公网安备 11010802027423号