聚合物有序孔凝胶模板制备三维有序二氧化钛材料

以聚合物有序大孔凝胶为模板,结合溶胶/凝胶过程合成了三维有序二氧化钛材料,重点研究了聚合物凝胶组成对无机材料形态的影响 当凝胶网络中不含酸时,得到无机单分散微球有序排列的结构.当聚合物凝胶含有酸时,得到无机有序孔材料.分析了酸在无机物的溶胶/凝胶过程中的催化作用和对产物结构的影响.

Synthesis and characterization of hybrid organic-inorganic materials based on EA-MAn-APTES and silica

Poly (EA-MAn-APTES)/silica hybrid materials were successfully prepared fromEthyl acrylate (EA), maleic anhydride (MAn) and tetraethoxysilane (TEOS) in the presence of acoupling agent 3-aminopropyltriethoxysilane (APTES),by free-radical solution polymerization and insitu sol-gel process. The mass fraction of TEOS varied from 0 to 25%. The hybrid materials werecharacterized by the methods of FT-IR spectra, solvent extraction, scanning electron microscope (SEM), transmission electron microscope (TEM), differential scanning calorimetry (DSC) andthermogravimetric analysis (TGA) measuring apparatus to get their structures, gel contents,morphologies, particle sizes and thermal performances. The results show that the covalent bonds arebetween organic and inorganic phases, gel contents in the hybrid materials are much higher, theSiO_2 phase is well dispersed in the polymer matrix, silicon dioxide exist at nanoscale in thecomposites and have excellent thermal stability.

Sol-gel synthesis and photoluminescence of LaPO_4:Eu^(3+) nanorods

Monoclinic LaPO4 nanostructures with uniform rod shape have been successfully synthesized by a simple sol-gel method.The procedure involves formation of homogeneous,transparent,metal-citrate-EDTA gel precursors,followed by calcination to promote thermal decomposition of the gel precursors to yield the LaPO4 nanoparticles.Their morphologies and structures were characterized by XRD,TEM,TG-DSC and HRTEM.The results indicate that single monoclinic phase LaPO4 nanorods are readily obtained at 800 ℃ within 3 h.Furthermore,photoluminescence(PL) characterization of the Eu3+-doped LaPO4 nanocrystals was carried out.The effects of calcination temperatures and Eu3+ doping content on the PL properties were elaborated in detail.Room-temperature photoluminescence(PL) characterization reveals that the optical brightness as well as the intensity ratio of 5D0-7F1 to 5D0-7F2 is highly dependent on the calcination temperature,and the Eu0.05La0.95PO4 nanophosphor shows the relatively promising PL performance with the most intense emission.

THE PREPARATION OF PEROVSKITE TYPE STRONTIUM TITANATE BY SOL-GEL PROCESS

By using strontium acetate and titanium n--butoxide [Ti(OBun)4] as starting agents, perovskite -- type double oxide SrTiO3 can be obtained by the sol--gel method. By means of infra-red spectra (IR), X--ray diffraction (XRD), differential thermal analysis (DTG), thermal gravimetry (TG) and scanning electron microscopy (SEM), basical factors, affecting the formation .of SrTiO3,have been discussed. IR results show that the acetic acid as a chelating ligand plays an important role in modifying the whole hydrolysis --condensation process. The addition of glycerol leads to obtaining clear and unique gels. The structure of SrTiO3 calcined at 800℃ is cubic.

Nanostructured Organic Alkali-Soluble Silicates for Industrial Application

The work describes the properties of soluble organic silicates and their applications to obtain nanocomposite materials. We analyzed the properties of the water-soluble high-modulus silicate systems and their technology for producing. The aim of this paper is the comparison properties of binders based on liquid glass containing strong organic bases silicates. We have shown how these systems are transformed from lower to higher oligomers through the formation of the silica sol and the implementation of the sol-gel process for these oligomers. We have conducted advanced research of various aspects of the use of these materials as the binder. Advantages of strong organic bases silicates in the preparation of heat resistant, nanocomposite materials are shown. Ways to obtaining quaternary ammonium silicates and their use to produce nanocomposites are proposed. Products obtained in this way can be used as a binder in the preparation of nanostruetured composite materials, water-based paints, coatings, etc. Modifiers have been proposed for making of hybrid nanostructured composite materials by a sol-gel process. There have been shown of structuring phenomena some aspects, synthesis and application of hybrid materials based on silica with grafted polymers. It has been shown, the possibility of modifying compositions using the nanostructuring agents such as tetrafurfuryloxysilane. This paper also describes methods for the synthesis of products for modifying a sol-gel process using organic soluble silicates. We are displaying their use for the production of new nanocomposite materials and coatings for protection against various external factors.

Research on the High-Strength Coating Preparation Methodology based on Acid Catalytic and Sol-Gel Method

In this paper, we conduct research on the high-strength coating preparation methodology based on acid catalytic and Sol-Gel method. This method has been widely used in the preparation of various functional thin film, film and protective film structure, etc. As a result of sol gel process continuously broaden the application field, this method has been more and more get the favor of people. Compared with other traditional preparation methods of inorganic material, sol-gel process has many characteristics. To adjust the solution acidity and add a small amount of acid or alkali can have the effect of＂ catalyst, its reaction process on sol to get and gel structure may also be affected. Our research analyze the topic theoretically and numerically which is meaningful.

模板技术合成有序介孔/大孔二氧化硅

以双重模板合成技术结合改进溶胶/凝胶过程制备有序双孔二氧化硅, 其中大孔的孔壁为介孔, 两种孔均相互连通. 大孔在干燥的聚苯乙烯胶体晶模板经高温烧结除去后得到, 除去由表面活性剂分子形成的自组织结构得到介孔. 电子扫描显微镜、透射电子显微镜和选区电子衍射实验结果证实了大孔和介孔的存在, 两种孔的尺寸分布均一并且在空间有序排列, 两种孔均相互连通, 这与氮吸附实验结果吻合. 此外, 研究了表面活性剂浓度和烧结条件对介孔尺寸、分布和孔的有序性的影响.