from    
to    
search  

 


“Beyond the Diffraction Limit of Light....” Integrated Fluorescent-freeMult...
5·18国际博物馆日活动预告 | 刘骁:奇仪重器——探索科学博物馆的奥秘
环境学术沙龙第656期:Strengthening the Science-Policy Interface on Chemicals,W...
物理系colloquium: Quantum-enhanced metrology: theory and applications
报告题目:
Fabrication and characterization of carbon-based biomorphic composites
 报告人:
Dr. Dickon H. L. Ng
Associate Professor
Department of Physics
The Chinese University of Hong Kong.
报告时间:
2005-11-04 14:30
报告地点:
焊接馆301室
主办单位:
机械系
  简介:

Bioorganic substances like woods or cellulose fibers can be converted into high strength and lightweight carbide-reinforced biomorphic composites. The preparation of these composites involves several steps: (i) transforming natural bioorganic structures to carbon-based bio-templates by drying and pyrolysis, (ii) wetting the carbon bio-templates by infiltration of gaseous or molten metals, or metal-organic solutions, and (iii) converting the wetted bio-templates to functional composites by heat treatment. Biomorphic products, synthesized by this technique, possess bioorganic structures as well as having superior properties of engineering composites of carbides. This presentation describes the synthesis and characterization of biomorphic SiO2/SiC/C and SiC/C composites that contained SiO2 and β-SiC nanostructures. Freshly cut Luk Bamboo (Bambusa Textilis var Fusca) slices were used as our starting material and converted to bio-templates, and the metal-organic tetraethylorhosilicate solution was utilized as a source for Si. In characterizing the products, we found that the tubular structure of bamboo was retained. In addition, micron-sized spheres and nanorods of SiO2 were observed on the walls of the vessels in the samples treated at temperature around 1200oC, while β-SiC nanobelts were found in those samples treated at about 1400oC.

今日相关信息
清华-日立未来先驱IT论坛
科学与危机
Steroid signaling in plants
 
同类别相关信息
基于底物设计的不称合成策略对
Surface Chemistry and Photochemistr...
Publishing in Chem from Cell Press
Engineering for Life Sciences: From...
【清华五道口金融家大讲堂】全球大趋势对...
学术活动