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基于葡萄糖的微/纳球形材料的合成与表征

Synthesis and Characterization of Micro/Nano Spherical Materials Based on Glucose

【作者】 邓文雅

【导师】 邱介山; 赵宗彬;

【作者基本信息】 大连理工大学 , 膜科学与技术, 2007, 硕士

【摘要】 开发新颖的合成路线是获取高性能材料的重要途径。材料进入应用领域的前提是制备工艺问题的解决,以期获得尺寸、形貌、维度、单分散性稳定可靠的材料。球形材料,特别是空心的球形材料,具有密度低、稳定性好、表面渗透能力强及光学性质特殊等特性,因而在催化剂载体、轻质材料、微反应器等领域应用前景广阔。本论文从葡萄糖出发,采用水热合成技术制备得到了一系列炭基和金属氧化物的球形微/纳米材料。并对产物的形貌、结构、组成及性质采用扫描电镜、透射电镜、X射线衍射、红外、热重等技术手段进行了表征。主要结果如下:1.以葡萄糖为原料,水热条件下制备得到了粒径和形貌可控的炭基微/纳米材料。没添加表面活性剂时,通过调控实验参数可控制备得到直径在150-800nm的炭基球状材料;通过改变非离子表面活性剂(吐温80)的加入量,制备得到了多形态(碗状、椭圆形及鸭梨形开口状)微/纳米尺度的炭基材料;所得到的炭基材料表面存在丰富的含氧官能团。2.以葡萄糖基活性炭微球为模板,制备了微米尺度空心球结构的ZnO。首先水热法合成锌/炭复合微球,然后高温氧化除炭。研究发现煅烧条件对于ZnO产物的结构有重要影响,在空气中煅烧复合微球可得到微米尺度的空心球结构的ZnO,球壳由团聚的纳米粒子组成;在氧气中煅烧复合微球则得到了ZnO纳米棒组装形成的海胆结构的ZnO。3.进一步调控合成过程,制备得到了金属氧化物为壳纳米金属Ag为核的复合纳米材料(Ag@ZnO)。以水热条件下制备得到炭包银(Ag@C)为模板制备Zn2+/Ag@C复合物,高温氧化除去炭质组分,得到了金属氧化物包Ag的rattle结构的材料。综上所述,本论文从葡萄糖出发,采用水热合成和模板转化技术,可控制备得到了数种类型各异的微/纳米功能材料:表面富含官能团的球形炭、ZnO空心球及ZnO海胆状结构、金属氧化物包覆纳米Ag的复合结构材料。成功实现了不同材料之间的结构转换,以及从单一材料向复合材料的转化过程,为微/纳米材料的控制合成提供了新颖的思路及可行的途径。

【Abstract】 Controllable synthesis of materials is of significant importance for their technological application and fundamental research. The synthetic procedure is the key issue for obtaining materials with controllable size, morphology, dimension, monodispersity and unique properties. Spherical materials, especially those with hollow structures, possess tailorable structures, low densities, high surface areas, and unique optical, electrical, and surface properties. They might meet the needs of scientists and have promising applications in vast areas of miniature sensors, artificial cells, fillers, catalysts, acoustic insulation, microchip reactors, delivery vehicle systems, and photonic crystals.This thesis focuses on the preparation of several functional materials, including carbon spheres, metal oxide spheres with hollow structures and metal oxide encapsulated Ag nanoparticles, with glucose as the starting materials. The as-obtained products were characterized by SEM, TEM, XRD, FTIR and TG techniques.The main results are summarized as follows:(1) Diverse morphologies of carbon materials were fabricated under hydrothermal condition with glucose as the carbon precursor. In the absence of surfactant, carbon spheres with different diameters have been controllably prepared by tuning the experimental factors, such as reactant concentration, reaction time and temperature. Carbon materials with elliptic, pear-like, and bowl-like morphologies were prepared with the assistance of a non-ion surfactant Tween 80. The surfaces of the carbonaceous materials were occupied by abundant oxygen-containing functional groups.(2) ZnO spheres with hollow structures have been prepared with the glucose-based carbonaceous materials as template. During the synthetic process, zinc/carbon hybrid microspheres are firstly acquired and then the carbon was eliminated by oxidation in air at elevated temperature. It was found that concentration of oxygen significantly has an influence on the ZnO hollow structures obtained. ZnO hollow spheres were formed when the oxidation occurred at low oxygen concentration, however, urchin-like materials made of ZnO nanorods were obtained at high oxygen concentration.(4) Coupling the reduction of noble metal salts and carbonization of glucose, Ag@C core/shell structures are synthesized. Using these Ag@C core-shell structures as template, several metal oxides hollow spheres encapsulated Ag nanoparticles are successfully synthesized.

  • 【分类号】TB383.1
  • 【被引频次】8
  • 【下载频次】894
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