A composite film with multiple anti-counterfeiting features was demonstrated by superposing quantum dots (QDs) polymer matrix (film A) and cholesteric liquid crystal film (film B) together. The first-line and second-line anti-counterfeiting characteristics were successfully implemented by employing thermochromic, angular photochromic, and circularly polarized discoloration of film B, respectively. By initiatively utilizing the different relative positions between the fluorescence emission peak (λ em ) of film A and the central selective reflection wavelength (λ m ) of film B at different temperatures, which resulted in changes in the fluorescence spectra or the different presence of latent patterns, the most important third-line anti-counterfeiting feature was successfully achieved.

A novel soft-matter composite film of ethylene-vinyl acetate and liquid crystal with an energy conservation efficiency of 40.4% is developed.

A series of novel chiral polysiloxane side chain liquid crystal polymers (PSCLCPs) with two different types of LC phases and three self-assembly arrangements were successfully synthesized via thiol–ene click chemistry.

Abstract:Organosilicon polymer materials play an important role in certain applications due to characteristics of much lower glass transition temperatures (T g ), viscosities, surface energy, as well as good mechanical, thermal stabilities, and insulation performance stemming from the higher bond energy and the larger bond angles of the adjacent silicon-oxygen bond. This critical review highlights developments in the synthesis, structure, and phase transition behaviors of polysiloxane-based side chain liquid crystal polymers (PSCLCPs) of linear and cyclic polysiloxanes containing homopolymers and copolymers. Detailed synthetic strategies are elaborated, and the relationship between molecular structures and liquid crystalline phase transition behaviors is systematically discussed, providing theoretical guidance on the molecular design of the materials.

A series of side-chain polysiloxane liquid crystalline elastomers, E-Cm (where m is the number of carbon atoms in the interim alkyl groups, and m = 4, 6, 8, 10), with binaphthalene derivatives as crosslinkings, were designed and synthesized. The mesophase structures of these elastomers were dependent on the value of m. The elastomers with m ≤ 8 could form cholesteric (Ch) phases, while both smectic A and Ch phases could be formed for the elastomer with m = 10. Blue phases can be achieved when m ≥ 8. Besides, the helical twisting power (HTP) of all the elastomers exhibits a turning point with changing temperature. Both the turning temperature and HTP have an apparent dependence on the value of m. By adjusting the interim alkyl chain length in the elastomers, both visible and near-infrared light wide-band reflective films can be obtained. The broadband reflection mechanism was confirmed by SEM investigations.