A library of thermotropic liquid crystals of inorganic nanoparticles and extraordinary performances based on their collective ordering

Inorganic nanoparticles are widely investigated due to their unique and fascinating physical and chemical properties. However, due to the strong interparticle interactions, they generally form irreversible random aggregates with elevated temperatures. This limits their technological applications considerably as the latter requires structural ordering and tunability. To address this, a versatile method of preparing solvent-free thermotropic liquid crystals of inorganic nanoparticles is presented. By chemically modifying the nanoparticles with a flexible organic surface layer, the nanoparticles self-assemble into ordered microstructures, possessing both ordering and fluidity in a solvent-free condition. A library of thermotropic liquid crystals, including 6 different shapes, 8 different compositions, and 18 different dimensions, is constructed. The flexible tuning of the particle properties and the intrinsic ordering and fluidity provide a powerful platform for the design and development of functional materials and devices with unique properties, such as polarization-dependent excitation, polarized photoluminescence, polarized photothermal response, and designable magnetic robot. • A versatile method of preparing solvent-free thermotropic liquid crystals of inorganic nanoparticles is presented. • A library of solvent-free TLCs of inorganic NPs, including 6 shapes, 8 compositions, and 18 dimensions, is constructed. • The intrinsic ordering and fluidity provide a platform for the design and development of functional materials and devices.