Diffuse Interface Field Approach to Modeling and Simulation of Multi-Phase Colloid Systems

Yu U. Wang, Michigan Technological University, DMR 0968792

Diffuse interface field approach (DIFA) is employed to develop new computational model to simulate self-assembly behavior of shape-anisotropic particles at curved fluid interfaces. A Gibbs-Duhem-type thermodynamic formalism is introduced to treat the heterogeneous Laplace pressure within the phenomenological model of multi-liquid-phase colloidal system, which is in agreement with Young-Laplace equation. The effects of capillary forces (interfacial tension and Laplace pressure) on particle self-assembly at fluid interfaces and capillary bridges spontaneously formed between closely packed colloidal particles in phase separating liquids are investigated. A self-stabilization mechanism is found, which operates through diffusive equilibrium of two-phase liquid morphologies and renders desired microstructural stability and uniformity to the capillary bridges. Capillary bridge formations in various compact colloid assemblies provide a promising route to in-situ (in-liquid) firming of fragile colloidal crystals and other compact colloidal microstructures via capillary bridges.

The PI and graduate student participated in Engineering Scholars Program and ASM Materials Camp–Teachers, two summer camp programs held at Michigan Technological University that brought Grades 9-11 girls and boys and high school teachers to campus to explore educational and career options in engineering and technology and get exposure to state-of-the-art science and engineering research. We presented seminars and demonstrations on computational materials research and shape memory alloys. These outreach activities are our efforts to nurture high school students’ interest in science, technology, engineering and mathematics (STEM).

Outreach: Summer Camp Programs at Michigan Tech

Yu U. Wang, Michigan Technological University, DMR 0968792