(369g) NSEF Poster Session: Computational Studies on the Structural Properties of Square Colloids with Offset Magnetic Dipoles
- Conference: AIChE Annual Meeting
- Year: 2022
- Proceeding: 2022 Annual Meeting
- Group: Nanoscale Science and Engineering Forum
- Time: Tuesday, November 15, 2022 - 3:30pm-5:00pm
We find that, as the strength of the dipolar interactions between squares overcomes the systemâs thermal energy, the dipolar squares assemble into single- or double-stranded assemblies, each with unique structures and phase diagrams in the temperature-density plane. Single-stranded assemblies of dipolar squares are associated with the formation of a percolated, or gel-like, state, while double stranded assemblies are associated with the formation of a nematic state. Using pair-wise potential energy calculations between dipolar squares, we show that whether a system of dipolar squares assembles into single- or double-stranded conformations depends on how the dipole is embedded within the square. Furthermore, by parameterizing the location of the dipole within the square, we predict that certain dipolar squares can transition between percolated and nematic states, depending on the systemâs density.
Our results highlight how colloidal particles with several degrees of anisotropy exhibit a rich phase behavior that sensitively depends on particle geometry and directional interactions. Our theoretical predictions are useful to colloidal scientists that are attempting to rationally synthesize particles with controllable properties. Finally, our studies of dipolar squares in the absence of a magnetic field provide a useful background as we extend our simulations to dipolar squares in the presence of an external magnetic field.