【作者】 魏顺新；

【导师】 吕荣文；

【作者基本信息】 大连理工大学 ， 应用化学， 2010， 硕士

【摘要】 复合纳米材料可以联合两种或者两种以上的组分,从而使它能够展现一些单组份材料所没有的性能,并且还可以通过组分互补性,赋予复合材料许多新的性能。而核壳材料作为复合材料的一个独特分支,根据结构、大小、组成排列的不同,可具有特殊的光、电、化学特性,因此越来越多的受到人们的青睐。在核壳材料中,空心核壳材料由于其独特的空腔结构以及热和机械性能好等特点而成为核壳材料中研究的热点。在空心核壳材料众多的合成方法中,软模板法由于操作简单、反应时间短、效率高、形成的壳体结构疏松等优点而被广泛采用。本论文采用非离子表面活性剂Brij(?)58作为软模板,在环己烷形成的反胶束微乳体系中,加入双功能配体,使配体的一端稳定住金属离子,另一端与表面活性剂的氧形成氢键,通过原位还原、包覆二氧化硅,分别合成了具有新型结构、颗粒尺寸40 nm左右的Cu@SiO2和Fe@SiO2空心核壳纳米颗粒,并对合成样品进行了透射电镜、XPS、XRD等表征,确定了样品的结构和组成,并探讨了空心核壳纳米颗粒的形成机理。另外,通过改变反应条件,考察了配体结构、配体浓度、还原剂种类、还原时间、氨水加入量等因素对Cu@SiO2及Fe@SiO2空腔形貌的影响,为以后合成形貌规整的样品奠定实验基础。此外,本论文还考察了R值(水与表面活性剂的摩尔比)、剪切速率、电解质加入量等因素对Brij(?)58反胶束体系黏度的影响,其可能为反胶束体系中纳米粒子的可控合成提供实验指导。更多还原

【Abstract】 Hybrid nano-material is composed of two or more kinds of components. It shows properties that one-component material does not and also behaves some new properties. Core-shell material has special optical, electrical and chemical properties according to their different structure, size and composition arrangement. This character of core-shell wins it more and more attention nowadays.Due to its unique cavity structure, good thermal and mechanical performance, hollow core-shell material has become a hot topic recently. Though there are various synthetic approaches for hollow core-shell material, the soft template method has been more widely used for its advantages, such as short reaction time, high product yields and structural robustness of the shells.This paper is about use the Brij(?)58 as a soft template to get reverse micelles microemulsion in cyclohexane and added the bifunctional ligand (one group to stablizie the metal ion, the other group to form hydrogen bonds with oxygen atoms of Brij(?)58) into the system, reducted, then encapsulated in silica to synthesize a new structure and particles size about 40 nm hollow Cu@SiO2 and Fe@SiO2 core-shell nanoparticles. The materials were characterized by TEM, XPS, XRD technologies. We further investigated the effects of ligand structure, ligand concentration, reducing agent type, reduction time, the quantity of ammonia and other factors on the sample morphology in different reaction conditions.In addition, the effects of R (mole ratio of water to surfactant), amount of electrolyte and shear rate on the viscosity of Brij(?)58/cyclohexane/water reverse microemulsion were also investigated. It might provide experimental guidance for controlled synthesis of nanoparticles.更多还原