Revisiting hierarchical arrangement of quantum dots in presence of liquid crystal media.

Liquid crystals have numerous applications in various fields ranging from drug delivery, gene therapy in biosciences to electronic display and sensors in the field of opt-electronics and material science. In recent years, the properties of liquid crystals have been tailored by truncating the terminal atom(s) or group of atoms and/or by doping different types of nanomaterials; such as nanodots, nanorods, nanotubes, nanoplatelets, etc. Controlled assembly of nanoparticles in liquid crystal media can provide an alternative method to tailor new and desired opto-electronic properties in uniquely arranged quantum dots. This self-assembly of nanoparticles produces new hybrid (composite) materials having large number of applications. Here, we review different applications of nanoparticles and liquid crystal systems and highlight different approaches for achieving the hierarchical arrangement of nanoparticles in liquid crystal media. Here, phenomena like quantum dot self-assembly, formation of hollow microstructures, memory effect, and formation of microcapsules, etc. in presence of liquid crystal media are revisited and discussed critically. Band-gap-tailoring has emerged as a major thrust area because of numerous applications in making opto-electronic devices. Band-gap of liquid crystals can be also be tailored either by doping (metal) atoms or by nucleating their nano-clusters after removing their terminal groups. This phenomenon creates a lot of attraction among scientists. Hierarchical arrangement of nano-dots in liquid crystal media has gained a lot of interest, as they can possess special functional properties; many of which are known whereas many others need to be discovered. Hierarchical arrangement of nano-clusters can be obtained either by doping atoms into liquid crystals followed by a nucleation process or by forming molecular architectures by weak coupling between quantum dots because of van der Waal forces. Functional properties such as magnetic, physiochemical, and opto-electronic properties of the hybrid systems are different from their constituent parts, and thus the hybrid systems can find a vital role in the field of nanoscience and nanotechnology. Because of the aforesaid reasons, it has gained much attention in the last few decades. [ABSTRACT FROM AUTHOR]