PNNL

Abstract

Proper statistical mechanics understanding of nanoparticle solvation processes requires an accurate description of the molecular structure of the solvent. Achieving this goal with standard molecular dynamics (MD) simulation methods is challenging due to large length scales. An alternative approach to this problem can be formulated using classical density functional theory(cDFT), where a full configurational description of the positions of all the atoms is replaced by collective densities of molecular atomic sites. Using an example system of negatively charged silica-like in an aqueous polar environment represented by a two-site water model, we demonstrate that cDFT can reproduce MD data at a fraction of the computational cost. An important implication of this result is the ability to understand how the solvent's molecular features may affect the system's properties at the macroscopic scale. A concrete example highlighted in this work is the analysis of nanoparticle interactions with sizes up to 100 nm in diameter.