EXCHANGE_inLCs · EXamining CHemistry and Nanoparticle Geometry Effects at the INterface of Liquid CrystalS

EXamining CHemistry and Nanoparticle Geometry Effects at the INterface of Liquid CrystalS

Arranging nanometer-sized objects into designed configurations with submicron precision is a major challenge in the development of nanotechnology. Adjusting the positioning of these objects tunes the overall macroscopic properties of the system. Designing scalable nanotechnology requires self-assembly, where components arrange themselves to minimize the system energy. Liquid crystals, materials renowned for the modern display industry, have emerged as an attractive medium for ordering nanoscale objects, due to the medium’s ability to form complex patterns. The dielectric and elastic properties of the constituent rod-like molecules of liquid crystals enable pattern formation that is controllable with confining surfaces and externally applied fields. Foreign inclusions, such as large molecules and particles, can disrupt the organization of liquid crystalline molecules, generating defects – local regions of disorder. In order to minimize the distortion in the medium, the foreign inclusions come together, self-assembling into shapes dictated by the liquid crystal defects. In order to develop new bottom-up approaches for designing nanomaterials, the EXCHANGE_inLCs project seeks to elucidate particle-liquid crystal interactions at the submicron scale, by EXamining CHemistry and Nanoparticle Geometry Effects at the INterface of Liquid CrystalS. To achieve this aim, the objectives of the project are to: 1) Vary the system GEOMETRY to explore confinement, particle size, and shape on assemblies, and 2) Vary the system CHEMISTRY to clarify the behavior of certain chemical species around particles. By varying system length scales and types of surface treatments, key interactions could be isolated. To probe both the effect of system geometry and chemistry, we studied several systems. First, we examined the assembly of lipids with varying hydrocarbon tail lengths at the interface of emulsions and thin films. The emulsion size was variable with the use of microfluidic techniques. Then, we investigated the assembly of nanoparticles that were synthesized in situ within thin films of liquid crystals via photo-induced polymerization. From comparing the interfacial assembly of particles to simulation results, we characterized the effective interparticle interactions. Third, we studied the role of particle size compared to the pitch of chiral liquid crystals in stabilizing two different types of defects: either point or ring defects, using both simulations and experiments. We lastly published a comprehensive review on how geometrical frustration from applied fields or boundary shapes can influence the pattern formation of liquid crystals with periodic ground states.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз