An azobenzene side chain liquid crystalline copolymer (MAzo-co-GMA) is successfully synthesized through copolymerizing the monomer 6-(4-((4-butylphenyl)diazenyl)phenoxy)hexyl methacrylate (MAzo) with glycidyl methacrylate (GMA). The obtained MAzo-co-GMA copolymer can form stabilized polymer brush on the surface after thermal annealing. The obtained polymer brush not only induces the alignment of liquid crystals but also shows a photothermal effect under UV light irradiation due to the azobenzene side group. On basis of these results, the LC cell with this polymer brush as the substrate is further used to fabricate the polymer-stabilized liquid crystal (PSLC) smart window. The resultant PSLC smart window shows the transparent state because the homeotropic alignment in the SmA* phase of PSLC is induced by the polymer brush on the surface of the LC cell. The opaque state can be achieved in the scattering N* phase by UV light irradiation or heating. The response time of the PSLC smart window can be regulated by adjusting the concentration of MAzo-co-GMA copolymer brush and the intensity of UV light. This kind of PSLC smart window with both thermal and UV response shows good reversibility and stability, which endows enormous promising applications in energy-saving devices.

The gold nanoparticles highly grafted by a liquid crystalline polymer (LCP) with azobenzene mesogens as the side chain (denoted as Au@TE-PAzo NPs) are successfully designed and synthesized by the two-phase Brust-Schiffrin method. The chemical structures of the monomer and polymer ligands have been confirmed by nuclear magnetic resonance, and the molecular weight of the polymer is determined by gel permeation chromatography. The combined analysis of transmission electron microscopy and thermogravimetric analysis shows that the size of the nanoparticles is 2.5(±0.4) nm and the content of the gold in the Au@TE-PAzo NPs is ca. 17.58%. The resultant Au@TE-PAzo NPs can well disperse in the nematic LC of 5CB. The well-dispersed mixture with appropriate doping concentrations can automatically form a perfect homeotropic alignment in the LC cell. The homeotropic alignment is attributed to the brush formed by Au@TE-PAzo NPs on the substrate, wherein the Au@TE-PAzo NPs gradually diffuse onto the substrate from the mixture. On the contrary, the pure side chain LCPs cannot yield vertical alignment of 5CB, which indicates that the alignment of 5CB is ascribed to the synergistic interaction of the nanoparticles and the grafted LCPs. Moreover, Au@TE-PAzo NPs show excellent film-forming property on account of their periphery of high densely grafted LCPs, which can form uniform thin film by spin-coating. The resultant thin film also can prompt the automatical vertical alignment of the nematic 5CB. Further, upon alternative irradiation of UV and visible light, the alignment of 5CB reversibly switches between vertical and random orientation because of the trans-cis photoisomerization of the azobenzene group on the periphery of Au@TE-PAzo NPs. These experimental results suggest that this kind of nanoparticles can be potentially applied in constructing the remote-controllable optical devices.

A liquid crystalline elastomer (LCE) as a kind of stimuliresponsive materials, which can be fabricated to present the threedimensional (3D) change in shape, shows a wide range of applications. Herein, we propose a simple and robust way to prepare a 3D shape-change actuator based on gradient cross-linking of the vertically aligned monodomain of liquid crystals (LCs). First, gold nanoparticles grafted by liquid crystalline polymers (LCPs) are used to induce the homeotropic orientation of the LC monomer and cross-linkers. Then, photopolymerization under UV irradiation is carried out, which can result in the LCE film with a cross-link gradient. Different from the typical LCEs with homogenous alignment that usually show the shape change of extension/ contraction, the obtained vertically aligned LCE film exhibits excellent bendability under a thermal stimulus. The nanoindentation experiment demonstrates that the deformation of LCE films comes from the difference in Young's modulus on two sides of the thin film. Simply scissoring the thin film can prepare the samples with different bending angles under the fixed length. Moreover, using a photomask to pattern the film during photopolymerization can realize the complex 3D deformation, such as bend, fold, and buckling. Further, the patterned LCE film doped with multiwalled carbon nanotubes modified by LCPs (CNT-PDB) can act as a light-fueled microwalker with fast crawl behavior.

All polymer solar cells (all-PSCs) is one of the important emerging renewable energy technologies. In this work, we use "jacketing" effect liquid crystalline polymer (LCP) with perylenediimide as side chain to fabricate all-PSCs. First, poly(2,5-bis{[6-(4-alkoxy-4′-perylenediimide)-6hexyl]oxycarbonyl}styrene) (abbreviated as PPDCS) is successfully synthesized via chain polymerization. The resultant polymer PPDCS forms stable smectic C (SmC) structure until decomposition. The electrochemical experiment indicates PPDCS shows deep LUMO energy level of −3.81 eV, thus, the nonconjugated PPDCS can be employed as acceptor materials to build all-PSCs. Atomic force microscopy (AFM) experiments show that the PBT7/PPDCS blend film forms a bicontinuous network-domains and the resultant film shows extensive absorption spectrum (300−800 nm) on UV−vis spectra. All-PSCs device fabricated by PTB7/PPDCS presents the best power conversion efficiency (PCE) of 1.23% after optimization, where the short-circuit current density (J sc ) is 4.34 mA cm −2 , an open-circuit voltage (V oc ) is 0.65 V, and a fill factor (FF) is 0.37. This work suggests that the nonconjugated LCP shows potential application for solar cell.

In this paper, the application progress and development of metal matrix composites (MMCs) are reviewed from the perspective of industrialization strategy. The development process of MMCs in China is briefly summarized. The key technological breakthroughs in the main preparation methods of MMCs, such as in-situ synthesis, stirring casting, powder metallurgy, and pressure infiltration, are introduced. Typical engineering application cases of MMCs that promote equipment upgrading are listed. The development trend of MMCs in the next five to ten years is prospected. In view of the challenges posed to material technology by the development of equipment technology in the field of national defense and national economy, the development opportunities and prospects of MMCs in the civil-military dual-use market are analyzed. Moreover, to overcome the deficiency of industrialization technology and industrial environment, development suggestions are put forward, including consolidating national industrialization platforms and talent cultivation bases, increasing national investment, speeding up the construction of standards and database systems, and developing low-cost and high-quality material preparation technology.