Liquid-crystal nanoscience: an emerging avenue of soft self-assembly

Abstract

Liquid crystals are finding increasing applications in a wide variety of fields including liquid-crystal display technology, materials science, bioscience, etc., apart from acting as prototype self-organizable supramolecular soft materials and tunable solvents. Recently, keeping in pace with topical science, liquid crystals have entered into the fascinating domains of nanoscience and nanotechnology. This tutorial review describes the recent and significant developments in liquid-crystal nanoscience embracing contemporary nanomaterials such as nanoparticles, nanorods, nanotubes, nanoplatelets, etc. The dispersion of zero-, one- and two-dimensional nanomaterials in liquid crystals for the enhancement of properties, liquid-crystalline phase behavior of nanomaterials themselves, self-assembly and alignment of nanomaterials in liquid-crystalline media, and the synthesis of nanomaterials by using liquid crystals as 'templates' or 'precursors' have been highlighted and discussed. It is almost certain that the 'fourth state of matter' will play more prevalent roles in nanoscience and nanotechnology in the near future. Moreover, liquid-crystal nanoscience reflects itself as a beautiful demonstration of the contemporary theme "crossing the borders: science without boundaries".

The peculiar electrical response of liquid crystal-carbon nanotube systems as seen by impedance spectroscopy

“…In recent years, nanoparticles (NPs) dispersions in liquid crystal (LC) matrices have gained increasing research interest [1,2]. The mixture may show modifications in the elastic and dielectric LC constants [3][4][5], the electro-optical properties [6,7] or the cell conductivity [3,6,8,9].…”

Inhomogeneous relaxation dynamics and phase behaviour of a liquid crystal confined in a nanoporous solid

“…chanical rigidity of the solid host and the large variation in electrical and optical properties offered by the plethora of available LC systems along with the advent of tailorable nanoporous media [31][32][33][34].…”

Discotic liquid crystal-nanoparticle hybrid systems

“…Both SWNTs and MWNTs have been dispersed in many LCs, and their effects on the electro-optical properties of LCs have been extensively studied by several researchers. 4,6,74,75 DLCs and CNTs have many similarities, for example, both are anisotropic materials; both possess self-assembling properties and often form hexagonal aggregates; and both exhibit 1-D conducting properties and have thus been considered as 'molecular wires.' These similarities prompted us to prepare DLC-CNT hybrid systems.…”

“…This topic has been well covered in many reviews, such as references 14-19. Like any other organic material, DLCs are basically insulators in their virgin state; however, they can be made electrically conducting by generating charges via chemical or photochemical doping. A number of dopants, such as bromine, iodine, AlCl 3 , NOBF 4 , trinitrofluorenone and ferrocenium ions, have previously been dispersed in DLCs to study the electrical conducting behavior of these materials. [20][21][22][23][24] However, the most remarkable effect was observed in the case of trinitrofluorenone doping.…”

“…From the emergence of this strong link between nanoscience and LCs, a new term, 'Liquid Crystal Nanoscience,' has evolved. 4,5 Assembling NPs into hierarchical and self-assembling structures is a fascinating way to prepare advanced functional materials.…”