Modeling the solid/liquid interfacial properties of methylimidazole confined in hydrophobic silica nanopores. (15th February 2021)

• Record Type: Journal Article
• Authors: Zheng, Weizhong; Sun, Weizhen; Zhao, Ling; Qian, Feng
• Is Part Of: Chemical engineering science. Volume 231(2021)
• Publication Date: 2021-02-15
• Subjects: Hydrophobic silica pore -- Confinement effect -- Solid-liquid interface -- Structure and dynamics -- Molecular dynamics simulation; Chemical engineering -- Periodicals; Génie chimique -- Périodiques; Chemical engineering; Periodicals; Electronic journals; 660
• DOI: 10.1016/j.ces.2020.116333
• Languages: English
• ISSNs: 0009-2509

Abstract

Highlights: Interfacial properties of MeIm confined in hydrophobic nanopores were investigated. The pore-size independent layering behaviors for the mass density were found. The layering behaviors are negligible for charge density. Smaller pore size leads to a more dramatic change of the structure and slower dynamics of the confined MeIm. Abstract: Many chemical processes proceed in confined environments of silica nanopore, in which the confined reactants or guest adsorbates show drastically different properties from the bulk system. Therefore, the solid/liquid interfacial structure and dynamics of 1-methylimidazole (MeIm) confined in the hydrophobic silica nanopore passivated by methoxysilane groups (-Si(Me)3 ) were investigated using molecular dynamics (MD) simulations. The mass density of the confined MeIm is layering and pore-size independent, while the negligible layering structure for charge density is observed. The smaller pore size gives rise to a significantly slower reorientation dynamics and translational diffusion of MeIm. In 2.8 nm pore, the parallel diffusion coefficient of MeIm is nearly 10 times larger than the perpendicular one, and their difference becomes smaller with the increase in pore size. Hopefully the insights from this work are helpful to a better understanding of the effects of hydrophobic silica pore on the confined behaviors of liquids.