摘要
由于纳米流控实验技术的限制,计算模拟已成为纳米流控行为的主要研究手段,其中基于经验势函数的分子动力学模拟是目前计算模拟研究所采用的首选方法.通过分子动力学模拟可以显性地获得液体分子在纳米通道中的具体运动细节(系统中所有原子的位移、速度和加速度),从而能够准确了解液体在纳米通道中的行为与系统控制参量的相互关系,包括外加载荷、纳米通道尺度、以及液体物理性质对纳米流控行为的影响.目前压力驱动纳米流控行为相关研究主要包括压力驱动下液体对疏液性纳米通道的浸润行为(流体从通道外进入通道)、液体在纳米通道中的传输行为(包括稳态和非稳态传输)、以及最终充满整个通道的过程,还涉及在纳米流控过程中液体的微观结构与势能变化.这些研究结果对于发展基于纳米流控行为的潜在应用具有重要指导意义,例如:设计具有更高能量吸收密度以及可以重复使用的新一代能量吸收耗散材料等.
Since experimental investigation at nanoscale is highly challenging, computational simulations have been the main tool for studying nanofluidic behavior, among which molecular dynamics simulations based on the empirical potential have been the most effective method. In molecular dynamic simulations, the details of liquid molecules transporting through nanochannels （including the displacements, velocities and accelerations of all atoms in the system） can be explicitly determined, based on which the relationship between the transport behavior of liquid through nanochannels and the controlling variables of system （e.g., the driven load, nanochannel size and physical properties of liquids） will be effectively understood. Currently, the studies of pressure-driven nanofluidic behavior mainly include the wetting behavior of liquid to hydrophobic nanochannel initiated by the external pressure （infiltration behavior of liquid to nanowetting nanochannel）, the transport behavior of liquid through nanochannel （including both equilibrated and non-equilibrated flows）, the filling process of nanochannel and the variations of the liquid structure and potentials inside nanochannel. These investigations can provide a useful guideline for the potential applications based on nanofluidic behavior, e.g., designing the new nanofluid energy absorption/damping systems which have a higher energy absorption density and can be repeatly used.
出处
《中国科学：物理学、力学、天文学》
CSCD
北大核心
2017年第7期136-164,共29页
Scientia Sinica Physica,Mechanica & Astronomica
基金
国家自然科学基金(编号:11172002)
国家重点基础研究发展规划(编号:2013CB933702)资助
关键词
纳米流控行为
计算模拟
分子动力学
能量吸收耗散
nanofluidic behavior
computational simulations
molecular dynamics
energy absorption and damping
