Stable soft cubic superstructure enabled by hydrogen-bond complex functionalized polymer/liquid crystal system

Abstract

A stable liquid crystal soft cubic superstructure (i.e., blue phase) in a wide temperature range was achieved by photopolymerizing a judiciously designed hydrogen-bond (H-bond) complex functionalized polymer/liquid crystal system.

Synergistic self-assembly of rod-like monomers in blue phase liquid crystals for tunable optical properties

“…9,10 Although the coexistence of DTC and disclination lines generates a stable structure, it also restricts the BP appearance to a narrow temperature range due to the competition between the local energetic minimization of DTC and the defects of instabilities in the global structure, thus limiting the practical applications. Numerous strategies have been implemented to design BPLC systems to stabilize BPs over a wider temperature range, including the synthesis of liquid crystal molecules with fluoride atoms, 11 and the introduction of low-weight molecules, [12][13][14][15][16][17][18][19] nanoparticles, 20,21 and polymers 22 into the system. The most conventional method for maintaining the cubic lattice structure is to polymerize reactive monomers within the BPLC yielding a temperature range greater than 60 K. 23 It is speculated that the polymer chains grow along the disclination lines after photopolymerization to stabilize the core of the BPLC structure, thus causing the expansion of the temperature range.…”

“…So far, numerous BPmonomer systems have been developed to achieve wider temperature range stability, for instance, rod-like monomers, flexible side-chain monomers, 25 bent-shaped monomers, 12,13,19 chiral dopants with reactive acrylate groups 26 and hydrogen bond formation. 16 This further enables the additional functionalities, such as photonic bandgap tunability 27 and the stimuliresponsive behavior of BP elastomers. 28,29 Another promising way to stabilize the BPs involves the inclusion of low molecular weight LC molecules such as LC dimers, 11 W-shaped, 14 bent and T-shaped H-bonded molecules, 15,17 banana shaped, 30 etc.…”