摘要：

Polymer nanocomposites are expected to be able to bridge the gap between polymers and ceramics. This is presumably due to the predominant interfacial interaction between nanoparticles and polymer segments, especially when interparticle distances are reduced and interfacial sections may structure a 3-dimensional network in the polymer matrix.

(i). Two series of SiO2/epoxy nanocomposites based on various epoxy matrices were in situ formed via a special sol-gel technique supplied by hanse chemie AG, in which silica nanoparticles in an average diameter of 25 nm were almost perfectly dispersed in the matrix. Significant improvements in stiffness and toughness of nanocomposites were observed when the interparticle distance became smaller than the nanoparticle diameter. Under this condition, the interphase may construct a three dimensional physical network, which will finally dominate the performances of these nanocomposites.

(ii). The creep resistance of both polyamide 66 and polypropylene could be significantly improved with a very low volume fraction of nanoparticles. It was found out that the nanoparticles contributed to remarkable reductions of the creep rate and the creep strain under various constant loads at different temperatures. It is assumed that nanoparticles may restrict the slippage and reorientation of polymer chains. In this way, they influence the stress transfer on a nanoscale, which finally results in these improvements. Our result should lead to improved grades to our understanding of "nano-effects" in polymer nanocomposites and of creep resistant thermoplastics for engineering applications.

张忠教授简历：

Dr. Zhong Zhang is a full professor at the newly established National Center for Nanoscience and Technology, China. Between 2001 and 2005, he served as a guest professor and a group leader at the Institute for Composite Materials (IVW), University of Kaiserslautern, Germany. His major research interests are to understand the processing-structure-property relationships of polymer nanocomposites. Dr. Zhang obtained his BS, MS, and PhD degrees from the University of Science of Technology of China, Hefei, China in 1990, 1996, and 1999, respectively. In 1997 and 1998, he worked at Karlsruhe Research Centre (Germany) and Rutherford Appleton Laboratory (UK) concentrating on low-temperature properties of polymers and composites. He started to work at IVW as an Alexander von Humboldt research fellow since 2000. In 2001, he obtained a very distinguished award from the same foundation, the Sofja Kovalevskaja Award. This award, financed by the German Federal Ministry for Education and Research within its "Investment in the Future Program", was especially created for young and highly talented scientists. This award has granted him one million Euros to establish an independent research team at IVW (including 3 postdoctoral and 3 PhD candidates) from 2001 to 2005. The objective of his research is to investigate the long-term behaviors (e.g. creep, fatigue and tribological properties) of short fibers/nanoparticles reinforced polymer composites, finally leading to an accelerative use of these materials in various industrial applications. Dr. Zhang was invited more than 30 times to give invited talks at world leading institutions and industries, and some plenary and keynote lectures at international conferences. Up to now, he published more than 70 research papers in refereed journals, together with a co-edited book (published by Springer), a German patent, and five book chapters. He is a member in the editorial advisory boards of some leading journals in the related fields since 2006, e.g. Composites Science and Technology, Journal of Composite Materials, Tribology International, and Applied Composite Materials.

Contact Information:

Prof. Dr. Zhong Zhang

National Center for Nanoscience and Technology, China

No.2, 1st North Street Zhongguancun

100080 Beijing, China

Tel: +86-10-62652738

Fax: +86-10-62650450

Email: zhong.zhang@nanoctr.cn