Structural transitions at solid-liquid interfaces

2019-10-10 09:52:36

liquid phase solid molecular transition

责任者: Ballamudi, R.K.;Bitsanis, I.A. 单位: Dept. of Chem. Eng., Florida Univ., Gainesville, FL, USA 来源出处: Adsorption(Adsorption (Netherlands)),1996//,2(1):69-76 摘要: In this paper we present the findings of our investigations using molecular dynamics, on molecularly thin films of n-octane confined between topographically smooth solid surfaces. We focus on the effect of increasing inducing liquid-solid phase transitions. We observed an abrupt transition in the structural features of the film at a critical value of the characteristic energy that quantified the affinity between solid surfaces and methylene units. This energetically driven transition was evident from the discontinuous increase of intermolecular order, a precipitous extension of the octane molecules and freezing of molecular migration and rotation. Increasing pressure had a similar effect in inducing a liquid-solid phase transition. The characteristics of the transition showed that it is a mild first order transition from a highly ordered liquid to a poorly organised solid. These findings demonstrate that the solidification of nanoscopically thin films of linear alkanes is a general phenomenon (driven either energetically or by increasing pressure), and does not require the aid of commensurate surface topography 关键词: freezing;high-pressure effects;molecular dynamics method;molecular reorientation;monolayers;organic compounds;solid-liquid transformations;solidification;surface energy;surface phase transformations;structural transitions;solid-liquid interfaces;molecular dynamics;molecularly thin films;n-octane;topographically smooth solid surfaces;abrupt transition;structural features;characteristic energy;methylene units;intermolecular order;freezing;molecular migration;molecular migration and rotation;liquid-solid phase transition;solidification;nanoscopic thin films