Dynamical density functional theory and its application to spinodal decomposition
Dynamical density functional theory and its application to spinodal decomposition
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DOI：
10.1063/1.1778374
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发表时间：
2004-09-01
影响因子：
4.4
通讯作者：
Evans, R
中科院分区：
文献类型：
--
作者：
Archer, AJ;Evans, R
我们给出了Marconi和Tarazona发展的经典流体的单体密度分布的动力学密度泛函理论的另一种推导[J。太棒了。110,8032(1999)]我们的推导进一步阐明了理论中固有的一些物理假设，并表明它并不局限于组成的流体。指粒子仅通过对势相互作用；相反，它适用于一般的多体相互作用。我们推导的起点是Smoluchowski方程，因此该理论适用于布朗粒子，因此也适用于胶体流体。在本文的第二部分，我们利用动力学密度泛函理论导出了一个既适用于早期也适用于中期的变节分解理论。对于旋节分解的早期阶段，我们的非线性理论等价于(广义)线性Cahn-Hilliard理论，但在以后的时间，它结合了密度涨落(模)的不同傅立叶分量之间的耦合，因此超越了Cahn-Hilliard理论。我们描述了一个模型(Yukawa)流体的计算结果，结果表明，耦合导致密度涨落中的第二个极大值的增长，其波数大于主峰的波数。(C)2004年美国学会。物理学的教授。
We present an alternative derivation of the dynamical density functional theory for the one-body density profile of a classical fluid developed by Marconi and Tarazona [J. Chem. Phys. 110, 8032 (1999)] Our derivation elucidates further some of the physical assumptions inherent in the theory and shows that it is not restricted to fluids composed. of particles interacting solely via pair potentials; rather it applies to general, multibody interactions. The starting point for our derivation is the Smoluchowski equation and the theory is therefore one for Brownian particles and as such is applicable to colloidal fluids. In the second part of this paper we use the dynamical density functional theory to derive a theory for spinodal decomposition that is applicable at both early and intermediate times. For early stages of spinodal decomposition our nonlinear theory is equivalent to the (generalized) linear Cahn-Hilliard theory, but for later times it incorporates coupling between different Fourier components of the density fluctuations (modes) and therefore goes beyond Cahn-Hilliard theory. We describe the results of calculations for a model (Yukawa) fluid which show that the coupling leads to the growth of a second maximum in the density fluctuations, at a wave number larger than that of the main peak. (C) 2004 American Institute. of Physics.