A novel protocol for confinement of liquid crystals in an architecture called hierarchical double networks of polymers can give next-generation solutions for low-energy consuming on-demand switchable smart windows operating between low and high transmittance.
Interpenetrating polymer networks are soft matter systems that innovatively optimise different functionalities such as mechanical, optical, and electrical properties to provide novel solutions in engineering and biomedical applications. A specific class of these architectures, labelled hierarchical double networks, synergistically combining rigid and soft networks to realize thermal, electrical, and optical properties are currently attracting much attention.
The research team of Dr. D S Shankar Rao, Dr. S Krishna Prasad, and Dr. Varshini G V, at the Centre for Nano and Soft Matter Science, Bengaluru have added a new dimension to this field by introducing double networks which are superimposed on liquid crystals. These networks are realized by two different and independently controlled & on-demand stimuli– light and temperature. While the former creates an orientationally self-assembled polymer network, the organogelation (converting to semi-solid material composed of gelling molecules organized in the presence of an appropriate organic solvent) of the second active component driven by temperature provides the second network which effectively traps the first one. The overall result is a well-controlled porous hierarchical network that confines the liquid crystal while allowing it to be electrically switched between its direction-dependent states and governing the dynamics through the created virtual surfaces of polymeric and gel nature.