Luminescence‐Driven Reversible Handedness Inversion of Self‐Organized Helical Superstructures Enabled by a Novel Near‐Infrared Light Nanotransducer

Abstract

Nanotransducer-impregnated self-organized helical superstructures are found to exhibit unprecedented reversible handedness inversion upon irradiation by the dual-wavelength near-infrared light. Upon near-infrared laser irradiation at 808 nm, the helical twist sense changes from right-handed to left-handed through an achiral liquid-crystal phase, whereas its reverse process occurs upon the near-infrared laser irradiation at 980 nm.

Self-activating liquid crystal devices for smart laser protection

“…Over the last few years, colloidal suspensions or nanocomposites from various nanomaterials such as metal nanoparticles [74][75][76][77], semiconductor nanoparticles [78], upconversion nanoparticles [79,80], and carbonbased nanomaterials [81][82][83][84][85] have emerged as extremely promising candidates for multiple-time-scale laser protections ranging from the microseconds, nanoseconds, picoseconds to femtoseconds regimes. To take the advantages of both nanomaterials and nematic LCs, great efforts have been made to develop the nano-dispersed non-linear nematic LCs with extraordinary properties, although there is still a long way to go for practical self-activating laser protection applications.…”

Self-organized cholesteric liquid crystal polymer films with tunable photonic band gap as transparent and flexible back-reflectors for dye-sensitized solar cells

“…[20][21][22][23] The most important property of CLCs is the selective light reflection according to Bragg's law: [24][25][26][27] λ = np where n is the average refractive index of the liquid crystals medium and p is the pitch defined as the distance along the helical axis of one complete rotation. The photonic band gap of these CLCs can be precisely controlled by modulating the helical pitch and twist sense.…”

Stimuli‐Directed Dynamic Reconfiguration in Self‐Organized Helical Superstructures Enabled by Chemical Kinetics of Chiral Molecular Motors

“…Among numerous external stimuli, light is known to have superior advantages of remote, instant, and precise controllability in an uncontacted way. In this regard, many efforts have been devoted to advance photoresponsive molecular switches and motors in the realm of intelligent liquid‐crystalline materials 8, 9, 10, 11, 12, 13, 14. Light‐driven dynamic self‐organized helical superstructures, i.e., cholesteric liquid crystals (CLCs), could be obtained upon doping the chiral molecular motors into achiral LC hosts, where the orientation of helical axes is typically expressed as three configurations: (1) parallel to the substrate with a fingerprint texture (lying helixes) resulting from the periodical helical pitch ( p ) defined as the distance as the molecular rotation by 360° twist along the helical axis; (2) perpendicular to the substrate with a Grandjean texture (standing helixes) performing unique Bragg reflection of circularly polarized light at wavelength λ = np , where n is the average refractive index of LC; (3) spatial disorder alignment with a focal conic (FC) texture, which can strongly scatter incident light.…”