溶胶-凝胶技术在有机／无机杂化材料制备中的应用

应用溶胶-凝胶法制备有机／无机杂化材料,可根据前驱体的种类和制备方法等对材料微观结构进行裁剪和优化,并可实现材料的功能化。有机／无机杂化材料根据有机相和无机相的比例不同,可分为有机改性陶瓷型杂化材料和陶瓷改性有机物型杂化材料两类。本文综述了应用溶胶-凝胶技术制备有机／无机杂化材料的原理以及应用进展。     

溶胶-凝胶包埋固定化酶的研究

介绍了溶胶-凝胶(sol-gel)包埋法制备固定化酶的基本过程和影响因素,着重论述了S iO2、有机改性硅胶和有机/无机杂化硅胶三类溶胶-凝胶基质材料制备固定化酶的特性和在催化反应中的应用,对溶胶-凝胶包埋法制备高性能固定化酶的发展前景予以展望。     

溶胶-凝胶法制备防腐耐磨杂化涂层的研究进展

有机无机杂化涂层兼有机涂层和无机涂层的双重特点和性能,具有优良的机械性能和阻隔作用,成为材料防护涂层研究的热点。阐述了溶胶-凝胶法合成有机/无机杂化涂层材料的原理和步骤,介绍了有机/无机杂化涂层在材料防腐耐磨方面的研究现状,提出了利用溶胶-凝胶法制备防腐耐磨杂化涂层存在的一些问题。     

溶胶-凝胶法制备有机-无机杂化材料研究进展

综述了国内外溶胶-凝胶法制备有机-无机杂化材料的研究进展     

有机-无机杂化材料制备质子交换膜的研究进展

综述了近年来采用有机-无机杂化材料制备质子交换膜的研究进展，重点介绍了由掺入了质子导电单元或经过磺化的有机-无机杂化材料制得的质子交换膜及由带磺酸基的有机硅通过溶胶-凝胶工艺制备的有机-无机杂化质子材料制得的交换膜，并从制备方法出发分析了每种质子交换膜的性能。     

溶胶-凝胶法制备有机-无机杂化纳米级功能材料

概要总结了溶胶-凝胶法制备有机-无机杂化功能材料的一些制备方法,说明了溶胶-凝胶法中存在的问题,并介绍了解决这些问题的研究.     

SiO2凝胶基质对邻苯二甲酸光、热性能的影响

采用溶胶-凝胶法在SiO2凝胶中掺入一定量的邻苯二甲酸,制备了有机-无机复合发光材料,并对热处理过程中邻苯二甲酸发光行为的变化及其热稳定性进行了研究,初步探讨了其发光性能及热稳定性与结构的关系.指出邻苯二甲酸由于受到SiO2凝胶的保护,其热分解温度比在空气中提高了近100℃.     

溶胶-凝胶法制备SiO_2/水性聚氨酯杂化材料研究进展

主要介绍了有机-无机杂化材料的特点、溶胶-凝胶法的原理,并对溶胶-凝胶法制备二氧化硅(SiO_2)/水性聚氨酯(WPU)杂化材料的不同作用类型进行了综述。最后对SiO_2/WPU杂化材料存在的问题提出了解决措施及相关的建议,并对该杂化材料的发展方向进行了展望。     

溶胶-凝胶法在材料制备中的应用

论述了溶胶-凝胶法的原理、工艺过程，并介绍了该方法在发光材料、锂离子导电材料、纳米材料的制备、生物材料、金属表面溶胶一凝胶涂层、杂化材料制备中的应用。     

有机-无机杂化复合材料膜内层叠制备新方法

叙述了有机-无机杂化复合材料溶胶-凝胶法、原位聚合法、共混法等制备方法。介绍了基于膜内层叠原理的有机-无机杂化复合材料制备新方法,该方法可以避免无机基团分布不均匀、无机基团难可控取向的缺点,将在有机-无机复合材料制备中发挥重要的作用。     

The Influence of the Structure of Pyromellitic Acid on the Luminescence Intensity of Graphene Oxide/Rare Earth Complexes Hybrid Materials

The development of graphene oxide/rare earth complexes luminescent materials is limited due to the strong quenching ability of graphene oxide. However, the hybrid materials with pyromellitic acid (PMA) as ligand not only have better performance, but also have stronger luminescence intensity. Herein we tested the effect of the carboxylic acid structure of PMA on the luminescence intensity of graphene oxide/rare earth complexes hybrid materials. Phthalic acid (PA), Isophthalic acid (i-PA) and Terephthalic acid (p-PA) are selected as test ligand, representing the o-position, meta-position and para-position effects of PMA. By comparing the luminescence intensity, we found that o-position effect is helpful for the ligand to sensitize rare earth ions, and meta-position and para-position effects are helpful for the graphene oxide sheets (GOSs) to improve the luminescence intensity of hybrid materials and inhibit the quenching effect of the GOSs. Furthermore, we speculate on the relationship between the distance of π–π stacking of GOSs and rare earth complexes and luminescence intensity of hybrid materials. This work provides an important reference for the design of graphene oxide/rare-earth aromatic carboxylic acid hybrid luminescent materials.

     

The preparation of graphene hybrid films decorated with poly[2-methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylene vinylene] particles prepared by non-solvent induced precipitation

A hybrid film of graphene decorated with poly[2-methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) nanoparticles is fabricated by a simple non-solvent induced precipitation method. The structure of the graphene film and graphene/MEH-PPV hybrid film are investigated by scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy. The large specific surface area of graphene sheets makes it an ideal support for depositing MEH-PPV nanoparticles as well as preventing aggregation of the nanoparticles. The graphene/MEH-PPV hybrid film is superhydrophobic, which is attributed to the increase in surface roughness as a result of random decoration of MEH-PPV nanoparticles on the graphene sheets. The MEH-PPV nanoparticles endow the graphene hybrid film with strong photoluminescence. The hybrid film also shows excellent conductivity and high thermal stability. The graphene/MEH-PPV hybrid film thus prepared may find potential applications in various devices where integrated properties of superhydrophobicity, conductivity and luminescence are required.     

PEG@Gd2O3:Tb复合中空纳米粒子的合成及其药物缓释性能

以稀土硝酸盐-乙二醇-硝酸混合溶液为前驱体,通过一步水热法合成无机/有机复合中空纳米粒子PEG@Gd2O3:Tb,对样品进行了表征,研究了其药物缓释性能. 结果表明,所得纳米粒子具有无机/有机复合中空结构,直径约200 nm,球壁厚度约20 nm,经800℃高温处理后为立方相的Gd2O3. 载药后的杂化中空纳米粒子比纯Gd2O3的释药速率更低,药物持续释放时间可达24 h,载药量为261.5 mg/g. 复合中空纳米粒子综合了无机纳米粒子的刚性和有机物质的韧性及生物相容性,拓展了空心球的潜在应用价值,在载药方面具有应用潜力.     

Effect of sol maturation on the preparation of luminescent ormosils

An UV‐polymerization approach was proposed to construct luminescence organic‐inorganic hybrid. Methacryloxypropyltrimethoxysilane (MAPTMS) was chosen as sol–gel precursor to prepare the host matrix and acrylic europium Eu(AA)₃ was used as guest dopants. Structural modifications during irradiation were evident in both the inorganic and organic domains of the hybrid material. The influence of condensation degree of the silicate network on the photopolymerization kinetics of organic moieties was investigated. It appeared that the sol maturation time was of vital importance to the phase homogeneity and optical transparency of materials. To get more efficient copolymerization and higher luminescence intensity of the target ormosils, two key processing factors including incorporation time and entrapping concentration are reported. Incorporation time when acrylic europium was introduced into the matrix during sol maturation is found to be helpful to overcome phase separation. The effect of entrapping concentration of europium(III) compound on the luminescence performance was further studied. Material synthesized by this approach has three advantages: optical transparency with little phase separation, organic and inorganic composite with interpenetrating network, covalent grafting of acrylic europium without luminescent species leakage. This “photopolymerization of molecular grafting” strategy is hopeful to offer a promising development for luminescent ormosil glasses. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45146.     

Fabrication of thermo-sensitive optical switches based on lanthanide-polyoxometalates and their “on-off” luminescence controlled by temperature

The temperature-responsive luminescent nanocomposites were prepared by the combination of poly (N-isopropylacrylamide) (PNIPAM) with lanthanide-polyoxometalates/SiO₂ spheres, exhibiting controlled reversible luminescent behavior with change in temperature. The structures and properties of nanocomposites were characterized by transmission electron microscopy, scanning electron microscope, FT-IR, UV-vis, dynamic light scattering and luminescence spectra. The research shows that the nanocomposites in aqueous solution display “on–off” luminescence by simple temperature stimuli. For example, the hybrid nanocomposites of PNIPAM/Eu-polyoxometalate/SiO₂ in aqueous solution show bright red luminescence under UV light, which could be observed by the naked eye when the temperature is below the lower critical solution temperature (LCST), showing the “on” state. However, the red luminescence of nanocomposites in aqueous solution is significantly decreased when temperature is above LCST, showing the “off” state.     

Strontium aluminate/polymer composites: Morphology,luminescent properties,and durability

Phosphor‐based polymer composites were prepared using a melt mixing and extrusion method. Morphology, luminescent properties, and Hamburg wheel test (HWT) of synthesized hybrid material were studied using various polymer matrices. The intensities of the luminescence of the strontium aluminates phosphors (SrAl₂O₄ : Eu,Dy and Sr₄Al₁₄O₂₅ : Eu,Dy) were substantially changed when incorporated into structurally and chemically different organic matrices. HWTs were performed to evaluate the durability of the polymers against simulated wheel loads and the effect of these wheel loads on the luminosity of the polymers. The decay slopes of various polymer–phosphor composites suggests that the simulated wheel load of the Hamburg test did not have a profound effect on the luminosity as such but the duration of luminescence was found to be shorter for the polymer–phosphor hybrid after the Hamburg test. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effect of “Ph–NH–CH2–” group on the luminescence properties of sol–gel silica xerogel

The effect of Ph–NH–CH₂– group (Ph: phenyl) on the luminescence properties of silica xerogel by sol–gel method has been investigated. The absorption spectra, excitation spectra and emission spectra of Ph–NH–CH₂– group embedded in the network of silica xerogel have a red shift with increasing the ratios of Ph–NH–CH₂– group in the samples. The relative photoluminescence (PL) intensity of the hybrid silica xerogel sample decreases with increasing the ratios of Ph–NH–CH₂– group. From the complex luminescent centers, the novel luminescence properties have been observed from the hybrid silica xerogel sample containing Ph–NH–CH₂– group.     

New luminescent lanthanide centered Si–O–Ti organic–inorganic hybrid material using sulfoxide linkage

A new sort of chemically bonded lanthanide organic–inorganic hybrid material has been constructed through the bifunctional sulfoxide molecular bridge (MSAPSi, which is functionalized 2-(methylsulfinyl) acetophenone (MSAP) by 3-(triethoxysilyl)-propyl isocyanate (TESPIC)) linking Si–O–Ti–O inorganic networks. The results suggest that the obtained hybrid materials are totally amorphous without phase separation phenomenon and exhibit the characteristic luminescence of Eu³⁺ and Tb³⁺ ions. Furthermore, the decay times and emission quantum efficiency of Eu³⁺ hybrid material are also determined.     

Synthesis of LaOF:Eu3+ Nanoparticles with Strong Luminescence Enhanced by Organic Ligands

LaOF:Eu³⁺ nanoparticles were successfully prepared by annealing LaF₃:Eu³⁺ nanocrytsals which were capped with SiO₂ shell. The SiO₂ shell effectively prohibited the growth of LaF₃:Eu³⁺ nanocrystals during the annealing process, and it was etched off after annealing to obtain the LaOF:Eu³⁺ nanoparticles. The LaOF:Eu³⁺ nanoparticles had a size comparable to the original LaF₃:Eu³⁺ nanoparticles. Inorganic–organic hybrid nanoparticles of LaF₃:Eu³⁺ and LaOF:Eu³⁺ nanoparticles with thenoyltrifluoroacetone (TTA) ligands were prepared. Strong luminescence as a result of the energy transfer from the TTA organic ligands to the LaF₃:Eu³⁺ and LaOF:Eu³⁺ nanoparticles was observed. The LaOF:Eu³⁺‐based hybrid nanoparticles exhibited stronger luminescence intensity and broader excitation spectral range than the LaF₃:Eu³⁺‐based hybrid nanoparticles. Effect of the content of TTA ligands on the luminescence of the LaOF:Eu³⁺ nanoparticles was investigated in detail.     

Hybrid light-emitting diodes from anthracene-contained polymer and CdSe/ZnS core/shell quantum dots

In this paper, we added CdSe/ZnS core/shell quantum dots (QDs) into anthracene-contained polymer. The photoluminescent (PL) characteristic of polymer/QD composite film could identify the energy transitions of anthracene-contained polymer and QDs. Furthermore, the electroluminescent (EL) characteristic of hybrid LED also identifies emission peaks of blue polymer and QDs. The maximum luminescence of the device is 970 cd/m² with 9.1 wt.% QD hybrid emitter. The maximum luminous efficiency is 2.08 cd/A for the same device.