(742c) Modelling External Stimuli on Liquid Crystal Assemblies By Surfactants and Nanoparticles at Nanoscale

Liquid crystals (LCs) continue to attract research attention because their ability to change orientational order is attractive for a variety of high-end applications, ranging from sensors to displays. [1] To aid experimental advancements, theoretical calculations have been conducted to quantify molecular driving forces responsible for the collective behaviour of LC molecules using the popular Dissipative Particle Dynamics (DPD) simulation method.

We previously identified how surfactant adsorption on cylindrical LC bridges can control orientational order. [2] It is found that the length of the surfactant hydrophobic tail determines the effectiveness by which the LC order is affected. For these surfactants, the surface density at the LC-water interface is an important knob that can be used to control the order of the LCs. When LC molecules are coalesce in a spherical droplet form, results differ from cylindrical formations. Surfactants self-assemble at the droplet boojums regardless of their molecular features. Additionally, increasing concentration of surfactants with appropriate morphology caused deviations from the spherical symmetry of LC droplets. [3] Motivated from these results, we focused on nanoparticles (NP) with different shapes and utilized LC droplets as templates for the self-assembly of these NPs. We modelled NPs that are in cubical, cylindrical, spherical and elliptical shapes. Preliminary analysis showed us that LC rods do work as a template when compared to one-bead size oil droplets. At the end of the analysis, we expect to obtain a comprehensive map of NP-LC interactions on nanoscale. The results presented could be helpful for designing novel surface-active compounds to develop advanced optics and/or sensing devices based on LCs.

1. D.-K. Yang, Fundamentals of Liquid Crystal Devices, John Wiley & Sons, 2014
2. Z. Sumer and A. Striolo, Physical Chemistry Chemical Physics, 2018, 20, 30514-30524.
3. Z. Sumer and A. Striolo, submitted.