Circularly polarized luminescent materials play an increasingly important role in display equipment and optical apparatuses. Herein, we design and synthesize a kind of luminescent liquid crystalline polymer with both chirality and aggregation-induced emission groups, namely, poly­(4-cholesterol formate-oxygen-tetraphenylethylene-methacrylate) (PT-Chol). Polarized light microscopy and X-ray scattering results show that the polymer forms a layered structure. Because of the existence of the tetraphenylethylene luminogen, the polymer shows highly efficient circularly polarized luminescence (CPL) properties with a luminescence dissymmetry factor (g lum) of ∼+0.45 after blending a specified amount of 4-cyano-4′-pentyl biphenyl (5CB), although the pure polymer does not show any CPL behavior in the solid state. A further experimental result shows that the mixture of PT-Chol and 5CB can form a chiral nematic liquid crystal (N*-LC) or smectic C* (Sm C*) phase in low concentration, but the complete dissolution of PT-Chol in 5CB does not result in the development of CPL properties. Gradually increasing the concentration of PT-Chol leads to the development of aggregation-enhanced emission behavior in the 5CB solution, which results in highly efficient CPL properties in the Sm C* phase. At the same time, the obtained circularly polarized luminescent material shows excellent stability, which is conducive to its applications in optoelectronic devices.

A series of high efficiency luminescent liquid crystalline polymers (LLCPs) based on aggregation-induced emission (AIE) and the "Jacketing" effect, namely, poly{2,5-bis{[2-(4-oxytetraphenylethylene)-n-alkyl]oxycarbonyl}styrene} (denoted as Pm, m = 2, 4, 6, 8, 10, 12), were successfully designed and synthesized via introducing tetraphenylethylene to the side group with different length spacers. Because of the AIE effect, the resultant LLCPs are completely free of aggregation caused quenching. The photophysical properties and phase behavior were studied via various techniques such as UV−vis absorption spectra, photoluminescence spectra (PL), polarized light microscopy (PLM), differential scanning calorimetry (DSC), and variable temperature one-dimensional wide-angle X-ray diffraction (1D WAXD). The results revealed that the resultant monomers showed typical AIE behavior and the polymers exhibited aggregation enhanced emission (AEE) behavior. Moreover, due to the "Jacketing" effect, the polymers showed high efficiency luminescence in the liquid crystalline state, which was significantly dependent on the spacer length (the solid-state quantum yields decreased from 52% to 18% with increasing spacer length). Meanwhile, the glass transition temperatures (T g ) decreased with increasing the length of spacers. With increasing the spacer length, the phase structure transformed from smectic A (SmA) (Pms, m = 2, 4, 6) to hexagonal columnar phase (Col H ) (Pms, m = 8, 10, 12). All the polymers presented good filmforming property and processing performance, which made them be promising materials for the luminescent devices.

Traditional luminescent liquid crystals (LLCs) suffer from fluorescence quenching caused by aggregation, which greatly limits their further application. In this work, a kind of novel LLCs (named carbonized polymer dot liquid crystals (CPD-LCs)) are designed and successfully synthesized through grafting the rod-shaped liquid crystal (LC) molecules of 4′-cyano-4-(4″-bromohexyloxy) biphenyl on the surface of CPDs. The peripheral LC molecules not only increase the distance between different CPDs to prevent them from aggregating and reduce intermolecular energy resonance transfer but also make this LLC have an ordered arrangement. Thus, the obtained CPD-LCs show good LC property and excellent high luminous efficiency with an absolute photoluminescence quantum yield of 14.52% in the aggregated state. Furthermore, this kind of CPD-LC is used to fabricate linearly polarized devices. The resultant linearly polarized dichroic ratio (N) and polarization ratio (ρ) are 2.59 and 0.44, respectively. Clearly, this type of CPD-LC shows promising applications for optical devices.

Circularly polarized luminescent (CPL) materials have attracted many attentions due to their potential applications in 3D imaging, anti-counterfeiting, etc. However, it is still a great challenge to achieve circularly polarized...

Smart windows can dynamically and adaptively adjust the light transmittance in non-energy or low-energy ways to maintain a comfortable ambient temperature, which are conducive to efficient use of energy. This work proposes a liquid crystal (LC) smart window with highly efficient near-infrared (NIR) response using carbon nanotubes grafted by biphenyl LC polymer brush (CNT-PDB) as the orientation layer. The resultant CNT-PDB polymer brush can provide the vertical orientation of LC molecules to maintain the initial transparency. At the same time, the smart window shows a rapid response to NIR light, which can quickly adjust the light transmittance to prevent sunlight from entering the room. Different from common doping systems, this method avoids the problem of poor compatibility between the LC host and photothermal conversion materials, which is beneficial for improving the durability of the device.