4月25日研究生学术前沿讲座——汪大洋教授

报告题目

Stimuli-responsive Nanoparticles Crossing Interfaces

报告时间

2013年4月25日(周四)下午3点

报告地点

微尺度国家实验室一楼科技展厅

报告人

汪大洋教授 
Ian Wark Research Institute, 
University of South Australia, Australia

报告摘要：

This talk will highlight our recent study of nanoparticle (NP) crossing oil/water interfaces. By anchoring stimuli-responsive polymer brushes on their surfaces, NPs can readily transfer between water and oil across oil/water interfaces in response to the environmental change in ionic strength, pH, and temperature for instance. This NP crossing interfaces is obviously associated with the hydration and de-hydration of the NP polymer brush coating, which is determined dominantly by the hydrogen bonding of the polymer brushes with water. Careful experimental and theoretical studies reveal that the water-to-oil NP transfer is correlated directly with the stimuli response of the polymer brushes anchored on the NPs, but the oil-to-water NP transfer mainly with the water structure at the oil/water interfaces. For instance, NPs can transfer from toluene back to and well dispersed in salty water with ionic strength as high as 0.5 M via cooling below 5 degree, in which the NPs agglomerate at room temperature. This temperature onset for oil-to-water transfer is less associated with the temperature response of the polymer brushes in either of the bulk phases. The revealed transfer mechanism disparity for the two directions during NP crossing oil/water interfaces should provide a better thermodynamic picture to describe the phase transfer. It will provoke a number of experimental and theoretical interest in temperature effect, especially cooling, on the structural stability, hydration, denaturing, and re-activation of biological molecules. The new interface causing properties of NPs will also lead to new design of vehicles to deliver biological labels and therapeutic substances to cross biological barriers. 
References: 
1.H. Duan, et al. Angew. Chem. Int. Ed. 2005, 44, 1717
2.E. Edwards, et al. Angew. Chem. Int. Ed. 2008, 47, 320.
3.Z. Mao, et al. Angew. Chem. Int. Ed. 2009, 48, 4953.
4.A. Stocco, et al Angew. Chem. Int. Ed. 2012, 51, 9647.

报告人简介：

Dayang Wang was born in Liaoning, China, in 1972. He studied chemistry at Jilin University, Changchun, China, where he obtained a B. Eng. in 1993 and a PhD in 1998 under co-supervision of Profs. Xinyi Tang, Tiejin Li, and Yubai Bai. In 1999 he worked as a postdoctoral fellow in the group of Prof. D. Lam in Dept. Mech. Eng. at Hong Kong University of Science and Technology,
 Hong Kong. Later in 1999 he joined the research group of Prof. F. Caruso, as a postdoctoral fellow, at the Dept. Interfaces, headed by Prof. H. Mö hwald, at the Max Planck Institute of Colloids and Interfaces (MPIKG), Potsdam, Germany. In 2000 he received an Alexander von Humboldt Research Fellowship. Since July 2003 he became a group leader at the Dept. Interfaces,
 MPIKG. In July 2010 he took up a tenured professor position at the Ian Wark Research Institute, University of South Australia, Adelaide, Australia. He has published 3 book chapters and 95 articles in peer-reviewed journals in Chemical Science, including 11 in Angew. Chem., 10 in Adv. Mater., 6 in Nano Lett., and 3 in JACS. The total citations of his publications are > 3300 and h-index is 32. He has delivered > 15 plenary and keynote lectures in international conferences. His current research interests include surfaces, interfaces (adsorption, adhesion, translocation, and phase transfer), gas and ion adsorption and transportation, crystallization, self-assembly, hydrogel, drug delivery, and nanomedicine.

主办单位：化学与材料科学学院，微尺度国家实验室，研究生院