摘要
由于流体在空间分布的不均匀性,可以导致流体在固液、汽液或液液界面形成与均匀流体非常不同的性质。目前对非均匀流体结构和热力学性质的研究主要有积分方程(IET)理论、密度泛函理论(DFT)和计算机分子模拟等。其中 DFT 方法在上个世纪70年代被引入到非均匀流体结构和热力学性质的研究,得到了较快的发展,经历了从简单流体到复杂流体和聚合物流体的发展与应用。不同 DFT 方法本质的区别在于对体系剩余自由能巨势泛函所采用的近似方法不同。在简单流体的 DFT 方法中,对剩余自由能的近似包括:1.局域密度近似,2.力口权密度近似,3.泛函展开近似,4.基本度量理论(FMT)方法,5.桥函数方法等等。考虑分子链的连接性,上述所有简单流体的 DFT 方法都被扩展到了分子流体和聚合物系统。通过引入平均场近似或者加权密度近似对链分子链节之间的 van der Waals 相互作用加以考虑,使 DFT 方法可以应用到更加实际的分子系统。
The thermodynamic and structural properties of fluid on the surface of solid-liquid,gas-liquid and liquid-liquid are very different from that of homogeneous fluid for the distribution of fluid varies in spatial.Current studies for those inhomogeneous fluids are focused on integral equation theory(IET),computer simulation and different versions of density functional theory(DFT).The DFT method was introduced into the study on the thermodynamic and structural properties of inhomogeneous fluid at the 70^(th)of last century.The essential difference of various versions of DFT lies in how one gets the approximate expression of the grand potential functional of inhomogeneous fluids.The approximation of excess free energy in simple fluids includes:1.local density approximation,2.weighted density approximation,3.functional expansion approximation,4.Fundamental-measure theory(FMT)method,5.bridge function method and so on.When one considers the connectivity of chain,all the above DFT of simple fluids can extend to molecular fluids and polymer systems.The DFTs of chain-like are conveniently applied to more practical molecular systems via considering the van der Waals interaction with mean field approximation or weighted density approximation.
出处
《中国科技论文》
CAS
2006年第1期1-12,共12页
China Sciencepaper
基金
国家自然科学基金(No.20236010)
教育部博士点基金(20050251004)
上海市教委E研究院-上海高校网格项目(200303)
上海市科委(05DJ14002)资助项目
