The research field of liquid crystals and their applications is recently changing from being largely focused on display applications and optical shutter elements in various fields, to quite novel and diverse applications in the area of nanotechnology and nanoscience. Functional nanoparticles have recently been used to a significant extent to modify the physical properties of liquid crystals by the addition of ferroelectric and magnetic particles of different shapes, such as arbitrary and spherical, rods, wires and discs. Also, particles influencing optical properties are increasingly popular, such as quantum dots, plasmonic, semiconductors and metamaterials. The self-organization of liquid crystals is exploited to order templates and orient nanoparticles. Similarly, nanoparticles such as rods, nanotubes and graphene oxide are shown to form lyotropic liquid crystal phases in the presence of isotropic host solvents. These effects lead to a wealth of novel applications, many of which will be reviewed in this publication.

Investigations on solitons have been carried out for decades in various areas of physics, such as nonlinear photonics, magnetic matter and superconductors. However, producing multidimensional solitary states and manipulation of their motion are still big challenges. In this work, we describe the formation of dynamic multidimensional solitons in a nematic and a cholesteric liquid crystal (LC). These solitons are self-confined director perturbations that propagate rapidly through the LC bulk and preserve their identities after collisions. We tune the velocity of the solitons by electric fields and control their trajectories through alignment layers. We find that the chirality of the cholesteric LC endows the solitons a wave-particle duality, and leads to a variety of fascinating interactions between solitons which cannot be observed in the achiral nematic LC. Furthermore, we also show that these solitons can be used as vehicles for 2D delivery of micro-cargos.

A modular approach to underexplored, unsymmetrical [1]benzothieno[3,2- b ][1]benzothiophene (BTBT) scaffolds, combining a transition-metal free Pummerer CH–CH-type cross-coupling and a Newman–Kwart reaction, delivers a library of BTBT materials.

Dissipative solitons are realized in nematic liquid crystals with positive anisotropies due to a nonlinear coupling of the director field to isotropic flow induced by ions. Influences of chirality, ion concentration and anchoring are investigated.

Skyrmions are continuous but topologically nontrivial field configurations that behave like particles. They play an important role in fields ranging from condensed matter to nuclear physics. Realizing and manipulating different kinds of motions of skyrmions are still great challenges. Here, three-dimensional skyrmions, in the form of double-twist tori terminated on two topological point defects called “torons,” are produced in chiral nematic liquid crystals with varied helical pitches. The spontaneous formation of skyrmions and high-degree multiskyrmion configurations called “skyrmion bags” are characterized by polarizing microscopy. The skyrmions show anomalous diffusion in the equilibrium state and perform collective directional motion driven by fluid flows, with a velocity controllable by electric fields and surface anchoring. They can be utilized as vehicles for microcargo transport. We also show that skyrmions can collide and form clusters with tunable shape, anisotropy, and fractal dimension.

The annihilation dynamics of s = ±1 topological defects with and without microparticles in a nematic liquid crystal were investigated and compared. The microparticle with a homeotropic surface anchoring can act as a s = +1 defect and produce a corresponding s = −1 defect nearby. Both of them attract and move towards each other. The speed of the positive defect induced by the microparticle is much slower than that of the negative defect, contrary to the situation without particles. The effects of electric field strength and frequency, particle size, the confining cell gap, and temperature were systematically investigated. The study shows that the dynamics of the annihilation process is related to a complex interplay between elastic attractions, viscous drag forces, backflow effects, director configurations and cell confinement.