Aerogels based on supramolecular self-assembly have become one of the hotspots in aerogel research. Herein, we reported a full biobased hierarchical supramolecular aerogel with low density, excellent flame retardant and fire-warning response which was obtained via a simple supramolecular self-assembly of folic acid tetramer (FA-tetramer) and sodium alginate. The density of the resultant FSNZ aerogels was ultralow at 14.4 similar to 17.8 mg/cm(3), and the thermal conductivity reaches as low as 33.6 mW/(m center dot K). Moreover, the resultant aerogel showed an excellent flame-retardancy and early fire warning capability (responses within 3 s), The heat and smoke release value were reduced by 53.6 % and 82.3 %, respectively. The flame-retardant mechanism of FSNZ aerogels is attributed to the zinc-catalyzed carbonization of FA-tetramer and alginate, while the fire early-warning mechanism is based on the temperature-responsive semiconducting properties resulting from the synergistic effect of zinc oxide and graphitic residue char. As a result, the supramolecular FSNZ aerogels in this work provide a novel strategy for the preparation of flame-retardant aerogels.

Two antimony nitrates were synthesized by the low temperature molten salt method. Both of them reveal large birefringence; especially, noncentrosymmetric (NH4)3SbF3(NO3)3exhibits a strong SHG coefficient of about 3.3×KDP.

Tellurate crystals are attractive for developing new nonlinear optical (NLO) materials in the mid-infrared region due to their wide transmission window. In this work, we report a quaternary tellurate oxide crystal, Li2GeTeO6, which exhibits a short cutoff edge (240 nm) with a powder second harmonic generation (SHG) response of 1.3 × KH2PO4 (KDP). The reported material reveals the largest band gap in the Li2MTeO6 (M = tetravalent cation) family. The first-principles calculations were used to illustrate the origin of the NLO effect. These results highlight the band gap engineering based on the cation substitution strategy for designing new NLO materials with balanced optical properties.

Li2HfTeO6 has been identified to function as a mid-IR transparent NLO switch with high figures of merit.

Nonlinear optical (NLO) crystals are key materials for solid-state lasers, which play an important role in modern science and technology. Recently, metal oxyfluorides have attracted much attention for next-generation NLO materials, in particular those used in the deep ultraviolet (DUV) and middle-infrared (MIR) regions. The incorporation of additional fluorine atoms allows new oxyfluoride-based NLO materials to span a more varied structure design palette than the oxide-only analogs. Therefore, metal oxyfluorides combine the advantages of fluorides and oxides, achieving wide transparent windows, large NLO coefficients, phase-match abilities, and high laser damage threshold values. For example, fluorooxoborates, fluorophosphates, fluorooxosilicophosphates, fluoroiodates, and fluorotellurites display new structural types and enhanced NLO performances. In this review, recently reported oxyfluoride NLO crystals are discussed. Their synthesis approaches, crystal chemistry, NLO performance, and structure-property relationship are reviewed. In addition, open challenges in both the synthesis and crystal growth of oxyfluorides are proposed. This work would provide a useful perspective on the exploration of next-generation NLO candidates with high performances to meet the urgent demands in DUV and MIR regions.

Oxyfluorides exhibit rich crystal structures that provide a new perspective for designing new NLO materials.

Lanthanide ions doped CaMoO4 with pie-like microstructures were synthesized by a hydrothermal method using phenol-formaldehyde resin (PF) as an inducer. The results of powder X-ray diffraction showed a tetragonal phase of both undoped and Ln3+-doped CaMoO4. The microscopical characterization technology revealed the formation process of the pie-like microparticles. As a morphology inducer, the PF molecules played an important role in the formation of phase structure. The as-obtained materials were characterized using different spectroscopic techniques including FT-IR, Raman spectrum, and PL. The emission color can be easily turned by adjusting the relative doping concentrations of lanthanide ions.

A facile method for the synthesis of a Ln3+ (Eu, Tb) doped BiPO4 (BPO) nanocrystals were developed using an environment-friendly low temperature hydrothermal method assisting with phenol formaldehyde resin (PFr). Structure and surface functional groups of BPO samples were characterized by XRD and IR patterns. Morphology was studied by SEM technology also. Furthermore, doped BPO display strong red and green emissions from Eu3+ and Tb3+ ions respectively, and the BPO suspension is selectively quenched upon addition Fe3+ ions, and there is barely any interference by other metal ions, thus making the nanocrystals as a potential Fe3+ ions Fluorescent Probe, and the detection limit is below micromole level.

A facile and green synthetic method for the synthesis of a Ln(3+)(Eu, Tb)-doped SrMoO4 (SMO) microcrystals were developed using an environment-friendly low temperature hydrothermal method assisting with phenol formaldehyde resin (PFr). The microcrystals show narrow distribution and uniform particle size, and strong red and green emissions from Eu3+ and Tb3+ ions, and it is selectively quenched upon addition Fe3+ ions, thus making the microcrystals as a potential Fe3+ ions sensing material, and the detection limit is nearly micromole level.

CaWO4 crystals were prepared by hydrothermal method assisting with phenol-formaldehyde polymer. The morphology can be controlled by polymer, and X-ray diffraction patterns results present a scheelite-type tetragonal structure, characteristic infrared active modes for O–W–O in the range from 500 cm[Formula: see text] to 4000 cm[Formula: see text] by Fourier transform infrared spectroscopic techniques. Raman results indicate that the crystals possess seven Raman active modes in the range from 100 cm[Formula: see text] to 1000 cm[Formula: see text]. A scanning electron microscopy study reveals that the particles exhibit uniform morphology. Luminescent properties were investigated by photoluminescence measurements, multicolor phosphors were obtained when Ca[Formula: see text] was substituted partly by lanthanide ions.

In order to prepare bio-nanocomposites with no-cytotoxicity, the rosin-based epoxy resin (MPAER) and castor oil-based polyurethane (COPU) were synthesized and carbon nanotubes (CNTs) was used to enhance the properties of curing MPAER/COPU materials. The curing reaction, dynamic mechanical and thermal properties of this system were characterized by FTIR, NMR, DMA, TG et al. The cytotoxicity of materials is evaluated for HeLa cells using a MTT cell-viability assay. The results showed that COPU can cure MPAER and CNTs can increase effectively the properties of MPAER/COPU nanocomposites. The Tg of MPAER/COPU/CNTs has the highest value when CNTs content is 0.4wt%, which is 52.4 degrees C higher than the pure MPAER/COPU. Thermal stability of the nanocomposites is enhanced by the addition of CNTs, the initial decomposition temperature Td5 of the sample No. 0.4 has increased from 284.5 to 305.2 degrees C, which is 20.7 degrees C higher than No. 0. The impact strength of the No. 0.4 film is 15kgcm higher than the pure resin system. The survival rate of HeLa cells to the products is greater than 90% within 48 and 72h, which demonstrate that this material has excellent biocompatibility and no obvious cytotoxicity for HeLa cells, which may be used in the medical treatment.

Ti-doped ZnO (TZO) films were grown by radio frequency (RF) magnetron sputtering using a Ti-doped ZnO ceramic target in an Ar+H2 atmosphere at room temperature. Both the experimental and theoretical methods were employed to investigate the effect of H in TZO films. As the H2 flow rate increased, the surface morphology changed from pyramid-like features to a crater-like topography and the root-mean-square (RMS) roughness increased. The crystal quality was found to deteriorate at first but subsequently improved at an optimum doping ratio. A resistivity of 7.97×10−4Ωcm and an average transmittance of more than 83% in the 400–1100nm range were obtained with an optimal H2 flow rate of 1.2 sccm. Results of theoretical calculations show that the H dopant behaves as a shallow donor in the TZO films. The doping position of H is located in a BC ⊥ configuration at the center of the Zn-O bond, in which the O atom bonded to a substituted Ti atom parallel to the c axis. The charge carrier bands shifted from Ti 3d and O 2p orbitals in the TZO film to Ti 3d and H 1s orbitals in H and Ti co-doped ZnO films.

Scheelite (CaWO4)-type microphosphors were synthesized by the precipitation method assisted with cetyltrimethyl ammonium bromide (CTAB). All compounds crystallized in the tetragonal structure with space group [Formula: see text] (No. 88). FE-SEM micrographs illustrate the spherical-like morphologies and rough surface. PL spectra indicate the broad emission peak maximum at 613 nm under UV excitation. Luminescence decay curves monitored by [Formula: see text] transition ([Formula: see text] nm) of Eu[Formula: see text] in doped CaWO4 are presented, the curves exhibit a single-exponential feature and the lifetime for doped CaWO4 is 0.61 ms.

Strontium tungstate crystals were prepared by hydrothermal method assisting with Phenol-formaldehyde polymer method. X-ray diffraction (XRD) results present a scheelite-type tetragonal structure, Fourier transform infrared (FT-IR) spectroscopic techniques present different infrared active modes for O-W-O within the wavenumber range from 500 to 4000 cm(-1) while Fourier transform Raman (FT-Raman) indicate that all the crystals show six Raman active modes in the range from 200 to 1000 cm(-1). A SEM (Scanning electron microscopy) study reveals that the particles have microrod morphology. Optical properties were investigated by photoluminescence (PL) measurements, multicolor phosphors are obtained when a certain amount of Sr2+ was substituted by different lanthanide ions.

报道了一种聚合物分散液晶(PDLC)膜在压力作用下从散射膜变为透明膜的实验现象,建议称之为PDLC膜的压光效应.介绍了与压光效应相关的PDLC的应变液晶、剪切液晶和拉伸液晶等概念;给出PDLC压光效应膜样品照片,偏光显微镜照片,电光特性光谱分析和压光效应光谱分析.提出PDLC膜压光效应的原理猜想,给出对PDLC膜光学性质的重新认识,认为只要每个液晶微滴中液晶分子取向一致了,无论不同微滴间液晶分子取向一致与否,PDLC膜都将透明.PDLC膜压光效应将对液晶基础科学提出新课题,将在许多不用加电的新型压光器件(按压窗、功能玻璃和光纤压力传感器等)领域有应用前景.