Evaluation of Interfacial Tension Using DPD

Dissipative Particle Dynamics (DPD) was used to compute an interface model of water and octane. Based on solubility parameters (SP values) obtained from Full-Atomistic Molecular Dynamics (FAMD) for each component, Flory–Huggins χ parameters were estimated, and DPD interaction parameters were set. Interfacial tension was evaluated from stress values in each direction, showing good agreement with experimental results.

Use Cases Highlights

Evaluation of interfacial tension using DPD
Determination of interaction parameters from solubility parameters
Agreement with experimental values

Construction of interfacial models

An interface formed by 3,000 water and 1,000 octane DPD particles is shown. The interface remains after relaxation. The J-OCTA modeling function allows easy construction.

Interface model of water and octane

Evaluation of interfacial tension and comparison with experiments

Interfacial tension was calculated from stress values in each direction using stress data. Tracking time variations, the average value was evaluated as 50.1 [dyn/cm], showing good agreement with the experimental value of 51.7 [dyn/cm].

Time variation of interfacial tension

Change in interfacial tension when interactions are varied

The interfacial tension was evaluated by varying the particle interaction parameter aij in DPD calculations. Since interactions in DPD represent repulsion, stronger interactions resulted in increased interfacial tension.