Related Experiment Video
Updated: Jun 27, 2026

Probing C84-embedded Si Substrate Using Scanning Probe Microscopy and Molecular Dynamics
Published on: September 28, 2016
Detachment of Dodecane from Silica Surfaces with Variable Surface Chemistry Studied Using Molecular Dynamics
Binbin Jiang1, Huan Hou2, Qian Liu2
1State Key Laboratory of Water Resource Protection and Utilization in Coal Mining, China Energy Investment Group, Beijing 102211, China.
Abstract:
The adsorption and detachment processes of n-dodecane (C12H26) molecules were studied on silica surfaces with variable surface chemistry (Q2, Q3, Q4 environments), using molecular dynamics simulations. The area density of the silanol groups varied from 9.4 to 0 per nm2. The shrinking of the oil-water-solid contact line was a key step for the oil detachment, due to water diffusion on the three-phase contact line. The simulation results showed that oil detachment was easier and faster on a perfect Q3 silica surface which had (≡Si(OH))-type silanol groups, due to the H-bond formation between the water and silanol groups. When the surfaces contained more Q2 crystalline type which had (≡Si(OH)2)-type silanol groups, less oil detached, due to the formations of H-bonds among the silanol groups. There were no silanol groups on the Si-OH 0 surface. Water cannot diffuse on the water-oil-silica contact line, and oil cannot detach from the Q4 surface. The detachment efficiency of oil from the silica surface not only depended on the area density, but also on the types of silanol groups. The density and type of silanol groups depend on the crystal cleavage plane, particle size, roughness, and humidity.
More Related Videos
Related Concept Videos
Van der Waals Interactions
Molecular Models
Electrostatic Boundary Conditions in Dielectrics
Consider a case where both the mediums across a boundary are two different dielectric materials. Recall that the electric field and electric displacement are proportional and related through the material's permittivity.
The Kinetic Model of Gases
Theories of Dissolution: The Danckwerts' Model and Interfacial Barrier Model

