新型有机聚合-无机杂化载体材料ZnPS-PVPA的合成及表征

采用直接沉淀合成法,在无模板剂存在下,使用聚（苯乙烯-苯乙烯基膦酸）、磷酸二氢钠作磷源合成了不同比例的新型有机聚合物-无机杂化材料聚（苯乙烯-苯乙烯基膦酸）-磷酸锌Zn（NaPO4）1-x（O3PG）x.mH2O（x=0.35～1.0,G是有机基团）,用FT-IR、TG、XRD、N2吸附、SEM等手段对其进行了表征,结合实验数据提出了其可能的理想结构模型。结果表明这类新型杂化材料具有规整的层状结构,有一定的比表面及较好的热稳定性,可以作为新型的催化剂载体材料。     

溶胶-凝胶法纳米WO3材料的合成、表征及气敏性能

采用溶胶-凝胶法制备了一系列掺杂有SiO2的WO3纳米粉体,通过TEM、XRD等分析手段对产物粉体的粒度、晶相结构进行了表征,测试了材料的气敏性能,探讨了煅烧温度、掺杂量、工作温度对材料气敏性能的影响。结果表明：适量SiO2的掺杂有利于提高WO3对NO2气体的灵敏度,其中掺杂量为3％（质量分数）的气敏元件在较低的工作温度下气敏性能突出。     

Investigation of Zr-incorporated mesoporous titania materials via nonsurfactant templated sol-gel route: Synthesis, characterization and stability

The synthesis of Zr-incorporated mesoporous titania materials was achieved by a HCl-catalyzed nonsurfactant templated sol-gel process, followed by solvent extraction to remove the urea template. The materials were characterized by FT-IR, X-ray energy dispersive spectroscopy (XEDS), nitrogen adsorption-desorption measurement (BET), powder X-ray diffraction (XRD) and transmission electron microscopy (TEM). Zirconia has been successfully incorporated into the skeleton of titania and the observed Zr/Ti compositions are close to the designed Zr/Ti molar ratios in the feeds. The content of zirconia has significant effects on the mesoporosity and the pore parameters as well as the thermal and hydrothermal stabilities of the materials. Anatase crystal structures were formed in the materials with low Zr/Ti molar ratios. As the Zr/Ti ratio is increased, the content of anatase structures decreases and the material becomes essentially amorphous at the Zr/Ti ratio of 1/1. The materials have narrowly distributed average pore diameters in the range of 2.5–5.1 nm and disordered pore or channel structures. The incorporation of Zr increases the thermal stability but decreases the hydrothermal stability of the materials.     

Preparation and characterization of epoxy-silica hybrid materials by the sol-gel process

A transparent organic-inorganic epoxy/silica hybrid material was prepared by epoxy resin, functionalized-epoxy resin, which was partially functionalized by 3-aminopropyl triethoxylsilane(APTES), and highly reactive polysilcic acid (PSA), which was prepared through hydrolysis and condensation of metasilicate salt. The properties of hybrid materials such as impact strength, tensile strength, glass transition temperature (T_g), thermogravimetric temperature (TGA), and thermal effect of the hybrid materials were studied. The size of PSA particles in THF measured by dynamic light scattering technique, ranged from 10–28 nm. The results of experiment indicated that modified epoxy resin possed better roughness than that of the pure epoxy resin. The structure of the hybrid materials was characterized by FT-IR spectroscopy and 29SiNMR spectroscopy.     

Fabrication of the monolithic materials via novel monocomponent sol-gel process

SiH(OC₂H₅)₃ was used as a gel accelerant to prepare transparent, noncracking, high-purity silica gel monoliths with a lower volume shrinkage and shorter gel time. The silica gel monoliths prepared via the monocomponent bulk sol-gel process possess a microporous structure and a good transmittance in the UV/Vis region, and consist of 89% silica and 11% small molecules. The text was submitted by the authors in English.     

新型芳香族多羧酸配体1,3,5-三(间苯二甲酸)的合成与表征

为了增加金属有机骨架材料对氢气的吸附势能叠加量以及得到配位不饱和的金属中心,从而提高材料对氢气的吸附焓,改善材料在常温下的储氢性能,通过SUZUKI偶联反应,设计合成了新型芳香多羧酸配体1,3,5-三(间苯二甲酸)。该新配体集中了合成NOTT-112和MOF-177的配体的特点。与合成NOTT-112的配体相比,新配体减少一个苯环的尺寸,将使聚合物材料的孔尺寸相应减小,增加对氢气的吸附势能叠加量。与合成MOF-177的配体相比,新配体的羧酸配位数增加1倍,将使聚合物中的晶体结构更加多样化。可以预测,用新配体合成的新型金属有机骨架材料可以兼顾NOTT-112及MOF-177的性能,对吸附储氢材料的研究开发具有重要意义。     

Synthesis and characterization of HAp-based porous materials

The synthesis and characterization of new hydroxyapatite-based porous materials are reported. These were prepared using synthetic hydroxyapatite (HAp) (Ca₁₀ (PO₄)₆ (OH)₂) of controlled particle size, different polymeric resins (rigid, semi-rigid and flexible) and a crosslinking agent to bond chemically all components. The pores were generated during the reaction between the hydroxyl groups of HAp and resin, and the blocked-isocyanate. The pore size was varied from 140 to 250 μm in diameter and the pore volume fraction from 25 to 60%; these pores are interconnected. With these characteristics they can be potentially used as implants and prosthesis for bone ingrowth applications. These materials posses high wearing resistance, low processing temperature, high hydrolytic stability, good mechanical properties and excellent adhesion to bone surface. They were characterized by: XRD, SEM, densitometry, abrasion and mechanical tests.     

Synthesis and characterization of cadmium titanium oxide powders by sol-gel technique

Uniform crystals of CdTiO₃ orthorhombic phase have been preapred by Sol-Gel method using titanium butoxide and cadmium acetate. For the first time the sample has been characterised detailedly to confirm the formation of pure single phase of CdTiO₃. It is observed that the sample sintered at 500°C for 5 h showed complete formation of the single phase of CdTiO₃ by X-ray diffraction technique. X-ray photoelectron spectroscopy measurement has been carried out for the bulk CdTiO₃ sintered at 500 °C for 5 h, which showed 20% of Cd, 20% of Ti and 60% of O indicating stoichiometric CdTiO₃. Surface morphology studies by scanning electron microscopy showed uniform crystals of CdTiO₃. The purity of the compound has also been checked by Energy Dispersive X-ray method indicating the absence of foreign ions apart from that, the ratio of Cd : Ti has been calculated and found to be 1 : 1 indicating the stoichiometric CdTiO₃.     

Synthesis and characterization of sol-gel silica films doped with size-selected gold nanoparticles

Homogeneous nanocomposite silica films uniformly doped with size-selected gold nanoparticles (AuNPs) have been prepared by a combined use of colloidal chemistry and the sol-gel process. For this purpose, stable thiol-functionalized AuNPs (DDT-AuNPs) were first synthesized by a two-phase aqueous/organic system and, subsequently, dispersed in an acid-catalysed sol-gel silica solution. The microstructural morphology of the samples was investigated by x-ray diffraction and field emission scanning electron microscopy. X-ray photoelectron spectroscopy (XPS) and UV-vis optical spectrophotometry were instead employed to investigate the elemental chemical behaviour and the evolution of the surface plasmon resonance (SPR) band of the AuNPs from their synthesis up to the formation of the Au-doped silica films. The results show that the size, shape and crystalline domains of the AuNPs remain unchanged during the entire preparation process, indicating that their aggregation or decomposition was prevented. XPS results show that the DDT-AuNPs lose the capping shells and oxidize themselves when dispersed in acid-catalysed sol-gel solutions, and that bare AuNPs are embedded in the SiO(2) films. A large broadening of the SPR band, observed for systems with DDT-AuNPs, suggests the presence of interface effects which cause a surface electron density lowering. Thiol chain detachment from the AuNPs determines an increase of the SPR peak intensity while the oxidation of the Au surfaces causes a red shift of its position. The latter is no longer observed in doped films, suggesting that no interfacial effects between bare AuNPs and the host medium are present.     

一种均苯型可溶性聚酰亚胺的研究

采用二步法合成了一种新型的均苯四甲酸二酐型 (均苯型 )聚酰亚胺 ,实验分别考察了聚酰亚胺的溶解性能及其特性粘度 (Iv)与玻璃化温度 (Tg)、热分解温度 (Td)的关系 ,并对其预聚体—聚酰胺酸的亚胺化过程进行了表征。结果表明 :该聚酰亚胺可溶于N ,N′ -二甲基甲酰胺等强极性溶剂 ;Tg和Td随Iv值增大而升高 ,Iv值较低时 ,其对Tg和Td的影响较显著 ;随着热处理时间的延长或温度的提高 ,亚胺化程度增加。     

铜铁氧体纳米晶的溶胶-凝胶自蔓延燃烧法合成和表征

以硝酸铜、硝酸铁、硝酸钴和柠檬酸为原料,采用溶胶-凝胶自蔓延燃烧法一步直接合成了单相Co0.5Cu0.5Fe2O4纳米晶.借助TG/DTA、IR、XRD和SEM等手段分别对溶胶-凝胶自蔓延燃烧机理、粉体在不同退火温度下的结构演化过程以及燃烧粉体的表面形貌进行了研究.结果表明,自蔓延燃烧过程是在硝酸根离子和羧酸根离子之间进行的热诱导阴离子氧化还原反应,其中,硝酸根离子作氧化剂,羧酸根离子作还原剂.干凝胶燃烧后,产物已经初步晶化,晶粒尺寸约20nm.经600℃,2h退火即可得到晶化较好的Co0.5Cu0.5Fe2O4纳米粉体,燃烧粉末为多孔结构,密度为2.9g/cm3.     

Synthesis and characterization of Al2O3 catalyst carriers by sol-gel

The sol-gel method has been used to synthesize alumina powder with high surface area from boehmite. The characteristics of the final powder product have been systematically studied in light of the preparation method and starting materials by fractional factorial design. The results show that the type of precursor and pH of the precursor sol are the most important parameters for the textural properties of the calcined alumina powder. When the calcination temperature is increased the type of precursor loses its significance, while the pH still has decisive importance after calcination at 1000°C, on pore volume and surface area. There is also a significant combined effect of several parameters on the surface area and the pore volume. The electrophoretic mobility, agglomerate size and size distribution have been determined as a function of the pH for one type of boehmite sol. The relation between characteristics of the precursor and powder properties is clearly emphasized.     

Synthesis and characterization of new anthracene-based semi-conducting materials

Two soluble anthracene-based organic materials (BPA-An1 and BPA-An2) have been synthesized and characterized. The optical properties of these π-conjugated systems were investigated by UV–Visible absorption and photoluminescence (PL) spectroscopies. The optical gaps were estimated from the absorption onsets of the thin polymer films; their values were 3.01 and 2.76?eV for BPA-An1 and BPA-An2, respectively. The PL spectrum of BPA-An2 exhibits a blue emission both in dilute solution and thin film. BPA-An1 showed a blue photoluminescence in dilute solution; in solid film, π–π interactions influence its optical behavior and a green emission was observed. The HOMO and LUMO levels were estimated using cyclic voltammetry analysis. Single-layer devices of the (indium-tin oxide/anthracene-based material/aluminum) configuration have been elaborated and showed relatively low turn-on voltages of 6.2–5.5?V for BPA-An1 and BPA-An2, respectively.     

Novel photorefractive sol-gel materials

We have developed new photorefractive media based on hybrid organic-inorganic materials containing a charge transporting (CT) molecule either as side-chain or main-chain substituents on the silica backbone. Second order nonlinear optical (NLO) chromophores were introduced either as side chain or as guest units. These materials were prepared by the sol-gel process in the form of thin films of a few μm-thick. NLO and photorefractive properties have been evaluated using electro-optic measurements, two beam coupling experiments and photoconductivity measurements.     

新型光敏聚酰亚胺的制备与研究

用3,3’,4,4’ 二苯甲酮四羧酸二酐分别与1 (3 氨基苯基) 3 (4 氨基苯基) 2 丙烯 1 酮(光敏性二胺Ⅰ)和 3,3’,5,5’ 四乙基 4,4’ 二氨基二苯甲烷(光敏性二胺Ⅱ),经溶液聚合、化学亚胺化,制备了一类新型可溶性的光敏聚酰亚胺。该合成方法简便,分子量容易控制,起始原料价廉易得,产品纯度与收率高。TGA、UV、GPC等研究结果表明所制备的树脂曝光波长能与工业Ⅰ线匹配使用,具有良好的耐热性能与感光性能。     

Synthesis and characterization of V- and Ti-substituted mesoporous materials

Mesoporous Ti- and V-containing materials have been synthesized with different degree of loadings via incorporation of titanium (IV) isopropoxide and vanadium (V) oxide in the initial precursor gels. These mesoporous materials were compared with pure siliceous MCM-41 synthesized at the same conditions without adding metal precursors. The UV–vis and Raman measurements confirmed that the vanadium and titanium were mainly tetrahedrally coordinated and their coordination is not changing after calcinations. At high amount of Ti and V, the regular mesoporous long-range order decreases, however, the V- and Ti-mesoporous samples do not collapse upon calcinations.     

Development and characterization of molecularly imprinted sol-gel materials for the selective detection of DDT.

Molecularly imprinting sol-gel materials for DDT using both a noncovalent and a covalent approach was examined. A nonpolar porous sol-gel network was created through the use of the bridged polysilsesquioxane, bis-(trimethoxysilylethyl)benzene (BTEB), as the principal sol-gel component. Noncovalent molecular imprinting was deemed unsuccessful, presumably because of the lack of strong intermolecular interactions that can be established between the DDT and the sol-gel precursor. A covalent imprinting strategy was employed by generating a sacrificial spacer through the reaction of two 3-isocyanatopropyltriethoxysilanes with one of two different template molecules: 4,4'-ethylenedianiline (EDA) or 4,4'-ethylidenebisphenol (EBP). After formation of the sol-gel, the bonds linking the spacer template to the matrix were cleaved in a manner that generated a pocket of the appropriate size bordered by amine groups that could aid in the binding of DDT through weak hydrogen bonding interactions. Experiments indicated that DDT could be bound selectively by such an approch. To generate a sensor, an environmentally sensitive fluorescent probe, 7-nitrobenz-2-oxa-1,3-diazole, (NBD) located adjacent to the DDT binding site was used to transduce the binding of analyte. EDA-imprinted sol-gels, deposited as films on glass microscope slides, were shown to quantitatively detect DDT in water to a limit-of-detection of 50 ppt with a response time of <60 s. Repeat measurements could be made with the same sensing films after rinsing with acetone between each measurement. The EDA sensing material was selective for DDT and other structurally similar molecules. However, the sensing film design was limited by the relatively minor changes in fluorescence intensity upon binding DDT. This situation may be remedied by an alternative methodology that can facilitate attachment of the NBD fluorophore in an optimal position proximal to the binding pocket.     

Synthesis and characterization of nanocrystalline CdZnO thin films prepared by sol-gel dip-coating process

Nanocrystalline Cd_xZn_1 − xO thin films with different Cd volume ratios in solution (x = 0, 0.25, 0.50, 0.75 and 1) have been deposited on glass substrate by sol-gel dip-coating method. The as-deposited films were subjected to drying and annealing temperatures of 275 °C and 450 °C in air, respectively. The prepared films were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, UV-vis spectroscopy and dc-electrical measurements. The results show that the samples are polycrystalline and the crystallinity of the films enhanced with x. The average grain size is in the range of 20-53 nm. The atomic percent of Cd:Zn was found to be 9.50:1.04, 6.20:3.77 and 4.42:6.61 for x = 0.75, 0.50 and 0.25, respectively. It was observed that the transmittance and the band gap decreased as x increased. All the films exhibit n-type electrical conductivity. The resistivity (ρ) and mobility (μ) are in the range of 3.3 × 10² − 3.4 × 10^− 3 Ω cm, and 1.5 − 45 cm² V^− 1 s^− 1 respectively. The electron density lies between 1.26 × 10¹⁶ and 0.2 × 10²⁰ cm^− 3.     

Synthesis and characterization of Mn-doped C@ZrSiO4 black pigment via non-hydrolytic sol-gel method

With the increasing popularity of the black decorative ceramics, the development of black pigment with good properties has become significant for the ceramic industry. A Mn-doped zirconium silicate encapsulated carbon (C@ZrSiO₄) black pigment was successfully prepared via non-hydrolytic sol-gel (NHSG) method at 800 °C, while MnCl₂ and carbon-containing precursors (tetraethoxysilane, TEOS) were used as Mn and in-situ carbon sources, respectively. The results demonstrated that the L* value of black pigment first decreased and increased with the increase of MnCl₂ content. The as-prepared pigment with the MnCl₂ content of 10 mol% showed a deep dark hue (L* = 27.64, a* = 0.67, b* = 0.68), while the pigment without Mn doping exhibited poor chromatic properties (L* = 51.18). Moreover, XPS and EPR results indicated that the Mn(II) and Mn(IV) replaced the Zr(IV) in ZrSiO₄, resulting in the formation of oxygen vacancies. In-situ carbon provided by TEOS incorporated into these oxygen vacancies, which can protect carbon from being oxidized. In addition, the prepared pigment exhibited higher chemical stability in acid/alkali solutions, favorable tinting strength and thermal stability in base transparent glaze, which displayed wide application prospect in the field of ceramic decoration.