Electro- and Photo-Driven Orthogonal Switching of a Helical Superstructure Enabled by an Axially Chiral Molecular Switch.

Self-organized functional soft materials, enabled by specific chemical architectures, are currently attracting tremendous attention because of their stimuli-responsive attributes and applications in advanced technological devices. A novel axially chiral molecular switch containing two azo linkages and six terminal alkyl chains on two elongated rod-shaped wings, that exhibits superior solubility, high helical twisting power, and reversible photoisomerization in an achiral liquid crystal host, is synthesized and utilized in the development of a photoresponsive, self-organized helical superstructure, that is, cholesteric liquid crystal (CLC). The planar CLC adopts a standing helix (SH) configuration because of surface alignment layers on the substrates.

Optically Reconfigurable Chiral Microspheres of Self-Organized Helical Superstructures with Handedness Inversion.

Optically reconfigurable monodisperse chiral microspheres of self-organized helical superstructures with dynamic chirality were fabricated via a capillary-based microfluidic technique. Light-driven handedness-invertible transformations between different configurations of microspheres were vividly observed and optically tunable RGB photonic cross-communications among the microspheres were demonstrated.

Frequency-Driven Self-Organized Helical Superstructures Loaded with Mesogen-Grafted Silica Nanoparticles.

Adding colloidal nanoparticles into liquid-crystal media has become a promising pathway either to enhance or to introduce novel properties for improved device performance. Here we designed and synthesized new colloidal hybrid silica nanoparticles passivated with a mesogenic monolayer on the surface to facilitate their organo-solubility and compatibility in a liquid-crystal host. The resulting nanoparticles were identified by H NMR spectroscopy, TEM, TGA, and UV/Vis techniques, and the hybrid nanoparticles were doped into a dual-frequency cholesteric liquid-crystal host to appraise both their compatibility with the host and the effect of the doping concentration on their electro-optical properties.

NIR light-directing self-organized 3D photonic superstructures loaded with anisotropic plasmonic hybrid nanorods.

Self-organized 3D photonic superstructures loaded with plasmonic hybrid nanorods were found to undergo structural transformation from body-centered cubic to simple cubic upon NIR-light irradiation resulting from the "photothermal effect" of gold nanorods. Furthermore, dynamic NIR light-directed red, green and blue reflections of the nanocomposites were demonstrated.

Near infrared light-driven liquid crystal phase transition enabled by hydrophobic mesogen grafted plasmonic gold nanorods.

Light-driven phase transition in liquid crystals is a fascinating endeavour from both scientific and technological points of view. Here we demonstrate the proof-of-principle that the photothermal effect of organo-soluble plasmonic gold nanorods can introduce the phase transition of thermotropic liquid crystals upon near infrared laser irradiation. Interestingly, the reverse process occurs when the laser is switched off.