报告题目
时间
2014-09-05 15:00:00
地点
船建学院木兰楼A1006室
报告人
Prof. Wen Hui Duan
Abstract
This presentation will provide an overview of the research activities within the Department of Civil Engineering at Monash University (Australia) on nano reinforced infrastructural materials. In particluar, a theoretical framework with supporting experiments is developed to address the effect of ultrasonication energy for carbon nanotube (CNT) reinforced OPC pastes. The distribution of CNT lengths and the concentration of dispersed CNTs are characterized using scanning electron microscopy images and UV-vis spectra. After ultrasonication, the length of CNT is found to follow log-normal distributions which show a shortening effect. The concentration of dispersed CNT increases with ultrasonication energy but reaches a plateau after about 250 J/ml. The distribution of CNT lengths and the concentration of dispersed CNTs are incorporated into a micromechanics-based model to simulate the crack bridging behavior of CNTs. Results show that the distribution of CNT lengths leads to better estimation of reinforcing effect than does the average length. Furthermore, for unit volume of dispersed CNTs, the reinforcing efficiency decreases monotonically with increased ultrasonication. Based on the proposed model, the predicted optimal ultrasonication energy (89 J/ml) for reinforcing is found before the dispersion plateau is reached. In addition, the preliminary results on graphene oxide (GO) reinforced OPC pastes will be presented as well with the comments on the advantages/disadvantages of GO for reinforcing purpose.
Biography
Dr Duan graduated from Tianjin University (China) in engineering mechanics with B.Eng. and M.Eng. in 1997 and 2002, respectively. He received his Ph.D. from the Department of Civil Engineering, the National University of Singapore (NUS), Singapore in April 2006. Dr Duan joined Monash University as a Lecturer in November 2008 and was appointed as an ARC Future Fellow in February 2013.Among 1013 Future Fellows awarded in Australia in last 5 years, Dr Duan is one out of 7 researchers working in the area of Civil Engineering.
Dr Duan conducted interdisciplinary research on nanocomposites and nanomechanics. By adding advanced nanomaterials such as carbon nanotubes and graphene oxide into conventional engineering materials such as epoxy, Portland cement, and geopolymer, Dr Duan has developed novel nanocomposites with high mechanical performances and reduced environmental impact. Hisresearch studies have resulted in more than 80 publications. Dr Duan's current h-index stands at 18 (as Aug 2014 via Google Scholar). In the last five years, Dr Duan was awarded 5 ARC grants on nanocomposites and nanomechanics totalling $AUD 2.0 million.