Thixotropic composite hydrogels based on agarose and inorganic hybrid gellants

Water can be used as oxidant in conjunction with metal particles to form metal-water propellant to increase the energy of propellant.For this application,water needs to be stored in form of solid and capable of becoming liquid when use.Stable and thixotropic hydrogel has good potential as water-retaining material and oxidant of metal-based propellant.In this study,we prepared organic/inorganic composite hydrogels by combining inorganic gellants hectorite and fumed silica with organic gellant agarose,respectively.The total content of the gellants can be reduced to less than 2%by adding agarose.The influence of agarose on water content,phase transition temperature,centrifugal stability and other basic physical properties of composite hydrogels were discussed.The results show that the composite hydrogels have better thixotropy and stability than pure inorganic hydrogels,and the gel-sol transformation can be realized by applying shear force or heating to the phase transition temperature.The composite hydrogels have good shear thinning ability and improved mechanical stability.Fumed silica/agarose hydrogels have better physical stability,while the thixotropy and shear thinning ability of hectorite/agarose hydrogels are better.

Flame Retardancy Enhancement of Hybrid Composite Material by Using Inorganic Retardants

This study aims to investigate the possibility of improving the flame Retardancy for the hybrid composite material consisting araldite resin (CY223). The hybrid composite was reinforced by hybrid fibers from carbon and Kevlar fibers on woven roving form (45o -0o), by using a surface layer of 4mm thick of Zinc Borate flame retardant. Afterward, the structure was exposed directly to gas flame of 2000oC due to 10 mm and 20mm exposure interval. The retardant layer thermal resistance and protection capability were determined. The study was continued to improve the performance of Zinc Borate layer mixed by 10%, 20% and 30% of Antimony Trioxide. To determine the heat transfer of the composite material the opposite surface temperature method was used. Zinc Borate with (30%) Antimony Trioxide gives the optimized result of the experiment.

Synergistic Optimization of Buried Interface by Multifunctional Organic-Inorganic Complexes for Highly Efficient Planar Perovskite Solar Cells

For the further improvement of the power conversion efficiency(PCE)and stability of perovskite solar cells(PSCs),the buried interface between the perovskite and the electron transport layer is crucial.However,it is challenging to effectively optimize this interface as it is buried beneath the perovskite film.Herein,we have designed and synthesized a series of multifunctional organic-inorganic(OI)complexes as buried interfacial material to promote electron extraction,as well as the crystal growth of the perovskite.The OI complex with BF4−group not only eliminates oxygen vacancies on the SnO_(2) surface but also balances energy level alignment between SnO_(2) and perovskite,providing a favorable environment for charge carrier extraction.Moreover,OI complex with amine(−NH_(2))functional group can regulate the crystallization of the perovskite film via interaction with PbI2,resulting in highly crystallized perovskite film with large grains and low defect density.Consequently,with rational molecular design,the PSCs with optimal OI complex buried interface layer which contains both BF4−and−NH_(2) functional groups yield a champion device efficiency of 23.69%.More importantly,the resulting unencapsulated device performs excellent ambient stability,maintaining over 90%of its initial efficiency after 2000 h storage,and excellent light stability of 91.5%remaining PCE in the maximum power point tracking measurement(under continuous 100 mW cm−2 light illumination in N2 atmosphere)after 500 h.

A New Method to Study the Sol-gel Transition Process of Organic/Inorganic Hybrid Materials

The sol-gel transition process of PMMA/SiO2 hybrid materials was first studied by means of the dynamic torsional vibration method. The different stages of the transition can be described by the change of torque. The temperature-dependent measurement of the gel time（ tg ） gives the possibility to determine the apparent activation energy.（ Ea ） of this transition according to Flory＇s gelation theory. The non-equilibrium thermodynamic fluctuation theory was used to predict the transition behavior. The isothermal transition experiments on hybrid sols with different TEOS（tetraethyl orthosilicate） contents were carried out. The results show that the Ea of a hybrid sol is higher than that of a non- hybrid sol of a TEOS-water-ethanol system. The increasing of TEOS content in a hybrid sol has no obvious effect on the Ea value, but it can enhance the sol-gel .reaction rate.

Organic-inorganic Hybrids Towards the Preparation of Nanoporous Composite Thin Films for Microelectronic Application

Silicon containing materials have traditionally been used in microelectronic fabrication. Semiconductor devices often have one or more arrays of patterned interconnect levels that serve to electrically couple the individual circuit elements forming an integrated circuit. These interconnect levels are typically separated by an insulating or dielectric film. Previously, a silicon oxide film was the most commonly used material for such dielectric films having dielectric constants( k ) near 4 0. However, as the feature size is continuously scaling down, the relatively high k of such silicon oxide films became inadequate to provide efficient electrical insulation. As such, there has been an increasing market demand for materials with even lower dielectric constant for Interlayer Dielectric(ILD) applications, yet retaining thermal and mechanical integrity. We wish to report here our investigations on the preparation of ultra low k ILD materials using a sacrificial approach whereby organic groups are burnt out to generate low k porous ORMOSIL films. We have been able to prepare a variety of organically modified silicone resins leading to highly microporous thin films, exhibiting ultra low k from 1 80 to 2 87, and good to high modulus, 1 5 to 5 5 GPa. Structure property influences on porosity, dielectric constant and modulus will be discussed.

SYNTHESIS AND CHARACTERIZATION OF NOVEL SOL-GEL DOPED ORGANIC/INORGANIC HYBRID NONLINEAR OPTICAL MATERIALS

hydroxy-4-nitro azobenzene (NHA) and 4-amino-4-nitro azobenzene (DO3) were prepared respectively from p-nitrophenylamine as a precursor compound. Two kinds of doped organic/inorganic hybrid nonlinear optical (NLO) materials containing NHA and DO3 were synthesized by Sol-Gel process. The preparation and properties of two NLO materials were studied and characterized by FTIR, 1H-NMR, UV-VIS, SEM, DSC and SHG measurements. The results show that the maximum doping amounts of NHA and DO3 in two doped hybrid NLO materials are 7.2(wt)% and 11.3(wt)% respectively, and the corresponding second-order NLO coefficients (d33 values) are 2.91×10 8esu and 6.14×10 8esu. Two doped NLO materials have relatively good RT stability, after 90 days at RT the d33 values can maintain about 85% of their initial values, but after 10h at 100℃ can only maintain about 50% of their initial values. In this report, the reasons for high-temperature instability of doped materials were discussed, and the possible improvements were also suggested.

Ag nanoparticles anchored organic/inorganic Z‐scheme 3DOMM‐TiO_(2‒x)‐based heterojunction for efficient photocatalytic and photoelectrochemical water splitting

Narrow spectral response,low charge separation efficiency and slow water oxidation kinetics of TiO_(2)limit its application in photoelectrochemical and photocatalytic water splitting.Herein,a promising organic/inorganic composite catalyst Ag/PANI/3DOMM‐TiO_(2–x)with a three‐dimensional ordered macro‐and meso‐porous(3DO MM)structure,oxygen vacancy and Ti^(3+)defects,heterojunction formation and noble metal Ag was designed based on the Z‐scheme mechanism and successfully prepared.The Ag/PANI/3DOMM‐TiO_(2–x)ternary catalyst exhibited enhanced hydrogen production activity in both photocatalytic and photoelectrochemical water splitting.The photocatalytic hydrogen production rate is 420.90μmol g^(–1)h^(–1),which are 19.80 times and 2.06 times higher than the commercial P25 and 3DOMM‐TiO_(2),respectively.In the photoelectrochemical tests,the Ag/PANI/3DOMM‐TiO_(2–x)photoelectrode shows enhanced separation and transfer of carriers with a high current density of 1.55 mA cm^(–2)at equilibrium potential of 1.23 V under simulated AM 1.5 G illumination,which is approximately 5 times greater than the 3DOMM‐TiO_(2).The present work has demonstrated the promising potential of organic/inorganic Z‐scheme photocatalyst in driving water splitting for hydrogen production.

Ferroelectric Properties and Applications of Hybrid Organic-Inorganic Perovskites

Hybrid organic-inorganic perovskites （e.g. CH;NH;PbI;） have attracted tremendous attention due to their promise for achieving next-generation cost-effective and high performance optoelectronic devices.These hybrid organic-inorganic perovskites possess excellent optical and electronic properties, including strong light absorption, high carrier abilities, optimized charge diffusion lengths, and reduced charge recombination etc., leading to their widespread applications in advanced solar energy technologies （e.g.high efficiency perovskite solar cells）. However, there is still a lack of investigations regarding fundamental properties such as ferroelectricity in these perovskites.As conventional ferroelectric ceramics are prepared at high temperature and have no mechanically flexibility,low-temperature proceed and flexible perovskite ferroelectrics have become promising candidates and should be exploited for future flexible ferroelectric applications. Here, ferroelectric properties in hybrid organic-inorganic perovskites and several state-of-the-art perovskite ferroelectrics are reviewed. Novel ferroelectric applications of hybrid organic-inorganic perovskites are discussed as well, providing guideline for realizing future high performance and flexible ferroelectric devices.

Hydrothermal Synthesis and Crystal Structure of Inorganic-organic Hybrid Compound [H_3NC_2H_4NH_2]VOPO_4

An inorganic-organic hybrid compound, [H_3NC_2H_4NH_2]VOPO_4 was synthesized by means of the hydrothermal method. It was crystallized in a monoclinic system, a space group P2_1/c, with the crystal cell parameters: a=0.92285(11) nm, b=0.72994(9) nm, c=0.98495(11) nm, β=101.280(3)°, V=0.65067(13) nm^3, M_r=223.02 g/mol, D_c=2.277 g/cm^3, Z=4, R=0.0315, ωR=0.0865, GOF=1.085. The VO_5N octahedra chains are corner-linked by PO_4 tetrahedra; the VO_5N octahedra are all trans-linked with V—O bonds being alternately short and long. The monoprotonated ethylenediamine was intercalated between the layers with one end coordinating to V and the other end as an H-bond donor interacting with a terminal O atom of PO_4 from a neighboring sheet. The elementary analysis, infrared spectrum characters and thermal stability were also given.

Composite bilayer films with organic compound-triggered bending properties

Organic compounds are widely used in both industry and daily life,and composite bilayer films with organic compound-triggered bending properties are promising for applications of transducers,soft robotics,and so on.Here,a universal and straightforward strategy to generate composite bilayer films with organic compoundtriggered bending properties is demonstrated.The composite bilayer films with organic compound-triggered bending properties are designed with bilayer structures,in which one layer is a porous polymeric membrane with appropriate solubility parameter that matches the value of organic solvents in order to produce prominent affinity to the solvent molecules,and the other layer is reduced graphene oxide membrane stacked on the porous polymeric membrane as an inert layer for restraining the swelling of the polymeric membrane on one side.Guided by matching the solubility parameters between solvent and polymer,a significant bending curvature of 27.3 cm-1 is obtained in acetone vapor.The results in this study will provide valuable guidance for designing and developing functional composite materials with significant organic compound-triggered bending properties.

Determination of elastic moduli of composite medium containing bimaterial matrix and non-uniform inclusion concentrations

Reservoir porous rocks usually consist of more than two types of matrix materials, forming a randomly heterogeneous material. The determination of the bulk modulus of such a medium is critical to the elastic wave dispersion and attenuation. The elastic moduli for a simple matrix-inclusion model are theoretically analyzed. Most of the efforts assume a uniform inclusion concentration throughout the whole single-material matrix. However, the assumption is too strict in real-world rocks. A model is developed to estimate the moduli of a heterogeneous bimaterial skeleton, i.e., the host matrix and the patchy matrix. The elastic moduli, density, and permeability of the patchy matrix differ from those of the surrounding host matrix material. Both the matrices contain dispersed particle inclusions with different concentrations. By setting the elastic constant and density of the particles to be zero, a double-porosity medium is obtained. The bulk moduli for the whole system are derived with a multi-level effective modulus method based on Hashin＇s work. The proposed model improves the elastic modulus calculation of reservoir rocks, and is used to predict the kerogen content based on the wave velocity measured in laboratory. The results show pretty good consistency between the inversed total organic carbon and the measured total organic carbon for two sets of rock samples.

Aromatic bromination with hydrogen production on organic‐inorganic hybrid perovskite‐based photocatalysts under visible light irradiation

Aromatic bromides are important chemicals in nature and chemical industries.However,their tra‐ditional synthesis routes suffer from low atomic economy and pollutant formation.Herein,we show that organic-inorganic hybrid perovskite methylammonium lead bromide(MAPbBr_(3))nanocrystals stabilized in aqueous HBr solution can achieve simultaneous aromatic bromination and hydrogen evolution using HBr as the bromine source under visible light irradiation.By hybridizing MAPbBr_(3) with Pt/Ta_(2)O_(5) and poly(3,4‐ethylenedioxythiophene)polystyrene sulfonate as electron‐and hole‐transporting motifs,aromatic bromides were achieved from aromatic compounds with high yield(up to 99%)and selectivity(up to 99%)with the addition of N,N‐dimethylformamide or its analogs.The mechanistic studies revealed that the bromination proceeds via an electrophilic attack pathway and that HOBr may be the key intermediate in the bromination reaction.

Thermal Studies and Analytical Applications of a Newly Synthesized Composite Material “Polyaniline Stannic Molybdate”

Polyaniline stannic molybdate—an organic-inorganic composite material, was prepared via sol-gel mixing of organic polymer polyaniline into matrices of inorganic precipitate of stannicmolybdate. The composite material synthesized at pH 1.2 showed an ion exchange capacity 1.8 meq/g for Na+?ions. Ion exchange capacity, pH titration and distribution studies were carried out to determine the preliminary ion exchange properties of the material. The distribution studies showed the selectivity of Hg(II) ions by this material. The effect of temperature on the ion exchange capacity of the material at different temperatures had been studied. The sorption behavior of metal ions was also explored in different surfactant media.

Grain size composition and transport of sedimentary organic carbon in the Changjiang River(Yangtze River) Estuary and Hangzhou Bay and their adjacent waters

Surface sediments from the Changjiang River （Yangtze River） Estuary, Hangzhou Bay, and their adjacent waters were analyzed for their grain size distribution, organic carbon （OC） concentration, and stable carbon isotope composition （δ13C）. Based on this analysis, about 36 surface sediment samples were selected from various environments and separated into sand （〉0.250 ram, 0.125-0.250 ram, 0.063-0.125 mm） and silt （0.025-0.063 mm） fractions by wet-sieving fractionation methods, and further into silt- （0.004-0.025 mm） and clay-sized （〈0.004 mm） fractions by centrifugal fractionation. Sediments of six grain size categories were analyzed for their OC and 613C contents to explore the grain size composition and transport paths of sedimentary OC in the study area. From fine to coarse fractions, the OC content was 1.18%, 0.51%, 0.46%, 0.42%, 0.99%, and 0.48%, respectively, while the δ13C was -21.64‰, -22.03‰, -22.52‰, -22.46‰, -22.36‰, and -22.28%0, respectively. In each size category, the OC contribution was 42.96%, 26.06%, 9.82%, 5.75%, 7.09%, and 8.33%, respectively. The OC content in clay and fine silt fractions （〈0.025 ram） was about 69.02%. High OC concentrations were mainly found in offshore modern sediments in the northeast of the Changjiang River Estuary, in modern sediments in the lower estuary of the Changjiang River and Hangzhou Bay, and in Cyclonic Eddy modern sediments to the southwest of the Cheju Island. Integrating the distribution of terrestrial OC content of each grain size category with the δ13C of the bulk sediment indicated that the terrestrial organic material in the Changjiang River Estuary was transported seaward and dispersed to the Cyclonic Eddy modern sediments to the southwest of the Cheju Island via two pathways： one was a result of the Changjiang River Diluted Water （CDW） northeastward extending branch driven by the North Jiangsu Coastal Current and the Yellow Sea Coastal Current, while the other one was the result of the CDW southward extending branch driven by the Taiwan Warm Current.

Fabrication of Inorganic–Organic Composites for Dental Restorative Materials—A Review

The paper is to review recent developments on composite dental restorative materials in terms of filler dimensions. The mechanical properties, biocompatibility and aesthetic performance are determined by fillers morphology, contents and chemical composition. We mainly summarized the 0-, 1-, and 2-dimensional fillers of composites used in dental restoration and their effects on the performance, especially the mechanical properties, which imply desirable applications for dental composites designed with these fillers.

Covalent organic frameworks/carbon nanotubes composite with cobalt(II)pyrimidine sites for bifunctional oxygen electrocatalysis

With characteristics and advantages of functional composite materials,they are commendably adopted in numerous fields especially in oxygen electrocatalysis,which is due to the significant synergies between various components.Herein,a novel bifunctional oxygen electrocatalyst(Co-CNT@COF-Pyr)has been synthesized through in-situ growth of covalent organic frameworks(COFs)layers on the outer surface of highly conductive carbon nanotubes(CNTs)followed by coordination with Co(Ⅱ).For electrocatalytic OER,Co-CNT@COF-Pyr reveals a low overpotential(438 mV)in alkaline electrolyte(1.0 M aqueous solution of KOH)with a current density of 10 mA cm^(-2),which is comparable to most discovered COF-based catalysts.For electrocatalytic ORR,CoCNT@COF-Pyr exhibits a low H_(2)O_(2) yield range(9.0%-10.1%)and a reaction pathway close to 4e^(-)(n=3.82-3.80)in alkaline electrolyte(0.1 M aqueous solution of KOH)within the test potential range of 0.1-0.6 V vs.RHE,which is superior to most reported COF-based catalysts.Hence,this research could not only offer an innovative insight into the construction of composites,but also facilitate the practical application of renewable fuel cells,closed water cycle,and rechargeable metal-air batteries.

Mechanical Behaviors of ZrO_2-Al_2O_3 Ceramic Composites with Y_2O_3 as Stabilizer

The ZrO2-Al2O3 ceramic composites were prepared by appropriate techniques with commercial ZrO2 and Al2O3 powders as raw materials and Y2O3 as stabilizer. The results indicate that with the introduction of Al2O3 into the ZrO2 matrix where the quantity of additive Y2O3 is 3.5% (mole fraction), the growth of ZrO2 grains is efficiently inhibited, which helps the ZrO2 grains exist in a metastable tetragonal manner; thus higher strength and toughness are acquired. When the content of alumina is 20% (mass fraction), the bending strength and fracture toughness of the composites are 676.7 MPa and 10 MPa·m1/2 respectively, the mechanical behaviors are close to those prepared with ZrO2 and Al2O3 powders synthesized through wet chemical approach. The mechanical behaviors of the composites are well improved owing to the dispersion toughening of alumina grains and phase transformation toughening of zirconia grains.

Immobilized nickel(Ⅱ) on organic-inorganic hybrid materials: The effective and reusable catalysts for Biginelli reaction

The immobilized nickel(II) on the organic-inorganic hybrid material was prepared and used as an effective catalyst for the Biginelli reaction.In the presence of the immobilized nickel catalyst,aromatic aldehydes reacted with ethyl acetoacetate and urea (or thiourea) smoothly to generate the corresponding Biginelli products in good to excellent yields without using any additive.The work-up procedure is very simple and practical.Furthermore,the silica-supported nickel(II) could be recovered and recycled for six consecutive trials without significant loss of its catalytic activity.

Solvothermal Synthesis and Crystal Structure of a Novel Inorganic-Organic Hybrid Material, Fe_2O(OH)(C_5H_4NCOO)SO_4

A novel inorganic organic hybrid material, Fe 2O(OH)(C 5H 4 ~NCOO)SO 4 was synthesized via solvothermal route using a reaction of FeCl 3·6H 2O, KCNS, and 4 cyanopyridine in aqueous solution of H 2O 2 and ethanol at 130 ℃ for 3 d. The compound crystallized in monoclinic space group P 2 1, with cell parameters a =0 73850(15) nm, b =0 65100(13) nm, c =1 0546(2) nm, β =90 36(3)°, V =0 50700(18) nm 3 and Z =2. The structure is constructed with inorganic layered [Fe 2O(OH)SO 4] + cations linked by organic (C 5H 4NCOO) - anions. The compound is thermally stable up to approximately 240 ℃.

Enhancement of superconductivity in organic-inorganic hybrid topological materials

Inducing or enhancing superconductivity in topological materials is an important route toward topological superconductivity.Reducing the thickness of transition metal dichalcogenides(e.g.WTe2 and MoTe2)has provided an important pathway to engineer superconductivity in topological matters.However,such monolayer sample is difficult to obtain,unstable in air,and with extremely low Tc.Here we report an experimentally convenient approach to control the interlayer coupling to achieve tailored topological properties,enhanced superconductivity and good sample stability through organic-cation intercalation of the Weyl semimetals MoTe2 and WTe2.The as-formed organic-inorganic hybrid crystals are weak topological insulators with enhanced Tc of 7.0 K for intercalated MoTe2(0.25 K for pristine crystal)and2.3 K for intercalated WTe2(2.8 times compared to monolayer WTe2).Such organic-cation intercalation method can be readily applied to many other layered crystals,providing a new pathway for manipulating their electronic,topological and superconducting properties.