Controlling the kinetics and gelation of photopolymerization is a significant challenge in the fabrication of complex three-dimensional (3D) objects as is critical in numerous imaging, lithography, and additive manufacturing techniques. We propose a novel, visible light sensitive "photoinitibitor" which simultaneously generates two distinct radicals, each with their own unique purpose-one radical each for initiation and inhibition. The Janus-faced functions of this photoinitibitor delay gelation and dramatically amplify the gelation time difference between the constructive and destructive interference regions of the exposed holographic pattern. This approach enhances the photopolymerization induced phase separation of liquid crystal/acrylate resins and the formation of fine holographic polymer dispersed liquid crystal (HPDLC) gratings. Moreover, we construct colored 3D holographic images that are visually recognizable to the naked eye under white light.

In this work, a novel fully autonomous photothermotropic material made by hybridization of the poly(N-isopropylacrylamide) (PNIPAM) hydrogel and antimony-tin oxide (ATO) is presented. In this photothermotropic system, the near-infrared (NIR)-absorbing ATO acts as nanoheater to induce the optical switching of the hydrogel. Such a new passive smart window is characterized by excellent NIR shielding, a photothermally activated switching mechanism, enhanced response speed, and solar modulation ability. Systems with 0, 5, 10, and 15 atom % Sb-doped ATO in PNIPAM were investigated, and it was found that a PNIPAM/ATO nanocomposite is able to be photothermally activated. The 10 atom % Sb-doped PNIPAM/ATO exhibits the best response speed and solar modulation ability. Different film thicknesses and ATO contents will affect the response rate and solar modulation ability. Structural stability tests at 15 cycles under continuous exposure to solar irradiation at 1 sun intensity demonstrated the performance stability of such a photothermotropic system. We conclude that such a novel photothermotropic hybrid can be used as a new generation of autonomous passive smart windows for climate-adaptable solar modulation.

Liquid-crystalline (LC) physical gels with a high modulus and low driving voltage were prepared through the self-assembly of sorbitol derivatives as gelators in a nematic liquid crystal, 4-pentyl-4 0 -cyanobiphenyl (5CB). The structural difference among the used gelators, i.e. 1,3:2,4-di-O-benzylidene-D-sorbitol (DBS), 1,3:2,4-di-O-p-methylbenzylidene-D-sorbitol (MDBS) and 1,3:2,4-di-O-m,p-dimethylbenzylidene-D-sorbitol (DMDBS), is only the number of methyl groups on their phenyl rings. The phase transition temperature, mechanical and electro-optical properties of three LC gels were systematically investigated. Compared with DBS, MDBS and DMDBS with methyl groups on phenyl rings have higher gelation ability in 5CB.The three LC gels exhibit good self-supporting ability with storage moduli higher than 10 4 Pa when the gelator content is increased to 1.5 wt%. At 3.0 wt% and a gelator content less than 1.0 wt%, both moduli of MDBS and DMDBS gels are obviously higher than that of DBS gel due to the enhanced reinforcement of the more rigid, thicker nano-fibrils and the formed nano-fibrillar network texture in MDBS and DMDBS gels. Also, the driving voltages of LC gels decrease in the order of DBS, MDBS and DMDBS gels with increase of LC domain size and nano-fibril diameter. For DMDBS gel with 3.0 wt% gelators, the threshold voltage and saturation voltage are only 0.5 and 3.5 V mm À1 , showing its potential application in self-supporting light-scattering electro-optical displays.

A porous 3D RGO/MnO2@PANI hybrid film and a 3D graphene aerogel were developed to fabricate a high-performance all-solid-state flexible asymmetric supercapacitor.

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