Shu Yang1

1, University of Pennsylvania, Philadelphia, Pennsylvania, United States

Assemblies of functional nanoparticles will lead to unique optical properties for potential applications in sensing, imaging, and light modulation. Liquid crystals (LCs), an active anisotropic soft matter, are sensitive to surface chemistry and surface topography. Their assemblies directed by surface cues (chemistry, topographies, and topologies) in the microscales could lead to a rich library of topological defects in nanoscale. These topological defects in turn offer new active media to trap, transport, and actuate the assembly and disassembly of nanoparticles, leading to dynamic and reversible switching of optical properties near LC phase transition temperatures. Here, by interplay of surface cues at the microscale to create topological defects and nanoscaled LC defect core and related core energy, we show dynamic tuning the (dis)assembly of gold nanorods (AuNRs) and nanoprisms in topological defects of nematic and semectic LCs near the phase transition temperature. Due to their own shape anisotropy, the nanorods can form side-to-side, end-to-end, or face-to-face assemblies. In turn, the localized surface plasmon resonance peak wavelength can be shifted more than 100 nm.