TEMPLATE SYNTHESIS OF NANOTUBULAR AND NANOPOROUS RARE EARTH OXIDE MATERIALS AND THEIR APPLICATIONS

本课题旨在通过模板法制备纳米多孔和纳米管状稀土氧化物材料，并对其光学性质进行表征，为合成新型纳米结构材料开辟一条新的模板途径。1)合成了以十二烷基硫酸盐为模板的掺Eu(III)六方纳米结构和纳米管状氧化稀土氧化物，以及不含表面活性剂的体相氧化物。所有生长的无定形或结晶度较差的材料都有微弱的发光带，而它们的1000℃焙烧产物的发光带强度有显著的增加。此外，纳米管体系中焙烧产物的能带数比块体体系中的约两倍。首次合成了以十二烷基硫酸盐为模板的稀土(Er，Tm，Yb，Lu)氧化物纳米管，并将其转化为中空的…更多的纳米管。结合我们以前的研究，进一步揭示了稀土元素可以根据它们的离子半径和反应时间而形成层状、六方纳米结构和纳米管状十二烷基硫酸盐和金属碳酸盐的任意一种或多种相的行为，可分为三类(Er-Lu，Eu-Ho和La-Sm)。研究发现，在反应混合物中加入十二醇可以得到高度分散的氧化物纳米管。通过在稀土氧化物骨架中引入对氨基苯磺酸阴离子，制备了一种新的纳米结构光响应材料。3)基于混合表面活性剂胶束组装的策略，开发了一种新的表面活性剂模板方法。首次用溶致混合表面活性剂六方结构液晶模板合成了外径为6 nm的铂和钯纳米管。类似的模板体系也被用于合成比表面积高达364m^2g^&lt；-1的羟基磷灰石纳米颗粒。采用单一表面活性剂模板法制备了苯酚-糠醛和氨基葡萄糖-甲醛聚合物纳米管或它们的络合物。较少

This project was intended to synthesize nanoporous and nanotubular rare earth oxide materials by a templating method, characterize their optical properties and develop a novel templating approach for synthesizing new nano-structured materials. The research results are summarized af follows :1)Europium(III)-doped hexagonal-nanostructured and nanotubular yttrium oxides templated by dodecylsulfate assemblies were synthesized, as well as surfactant free bulk oxides. All the as grown materials with amorphous or poorly crystalline frameworks gave weak luminescence bands, whereas the bands for their 1000℃-calcined products showed a remarkable increase in intensity. Moreover, the bands for the calcined products in the nanotube system were enhanced by about two times than those for the bulk system. Three Eu^<3+> sites were detected for all the calcined samples.2)Rare earth (Er, Tm, Yb, Lu) oxide nanotubes templated by dodecylsulfate assemblies were first synthesized and converted into a hollow … More nanotube. In connection with our previous studies it was further revealed that the rare earth elements can be classified into three groups (Er-Lu, Eu-Ho and La-Sm) according to their behavior to form any one or more phases of layered, hexagonal-nanostructured and nanotubular dodecylsulfate complexes and metal carbonates depending on both their ionic radius and reaction time. The oxide nanotubes were found to be obtainable in a highly dispersed form on addition of dodecanol to the reaction mixture. A new nanostructured photo-responsive material was prepared by the incorporation of p-aminobenznesulfonate anions into the rare-earth oxide framework.3)A new surfactant templating approach was developed on the basis of a strategy to make use of mixed surfactant micellar assemblies. Platinum and palladium nanotubes of 6-nm outer diameter were first synthesized from lyotropic mixed surfactant hexagonal-structured liquid crystal templates. A similar templating system was also applied to the synthesis of hydroxyapatite nanoparticles with a surface area of as high as 364 m^2g^<-1>. Phenol-furfural and glucosamine-formaldehyde polymer nanotubes or their complexes were synthesized by a single surfactant templating method. Less