地点：物理学院大报告厅

报告人：Naomi J. Halas, Rice University

报告人简介：

Naomi Halas is the Stanley C. Moore Professor of Electrical and Computer Engineering at Rice University, with appointments in the Departments of Chemistry, Physics and Astronomy, Biomedical Engineering, and Materials Science and Nanoengineering. She is Director of the Laboratory for Nanophotonics at Rice, and Director of the Rice Quantum Institute. She is one of the pioneering researchers in the field ofplasmonics, creating the concept of the “tunable plasmon” and inventing a family of nanoparticles with resonances spanning the visible and infrared regions of the spectrum. She is author of more than 250 refereed publications, and has presented more than 450 invited talks. Sheis a member of the National Academy of Engineering and theNational Academy of Sciences of the United States. She is a recipient of the American Physical Society 2014 Frank Isakson Prize for Optical Effects in Solids and the R. W. Wood Prize of the Optical Society of America. She is a member of the Editorial Advisory Board ofChemical Physics Letters and ACS Nano,and an Associate Editor of Nano Letters.

内容简介：

It was recently discovered that illuminating a solution of broadly absorbing nanoparticles dispersed in water results in vapor generation without the requirement of heating the fluid volume.[1] Using sunlight, approximately 80% of the energy absorbed by the nanoparticle solution is directly converted to steam generation, with only 20% resulting in heating of the liquid. To understand this unusual property we need to examine the intimate connection between the optical properties and the heat transfer properties of nanoparticle-laden liquids, a regime not well investigated previously. Comparing single nanoparticle light-induced heating measurements with studies of light-induced steam generation in solutions of nanoparticles, we observe the importance of collective optical effects-multiple light scattering by absorber-scatterer nanoparticles- in this phenomenon.[2]In addition to steam generation, when nanoparticles are dispersed within a mixture of liquids and then illuminated, the properties of the distillate can diverge dramatically from those observed for standard distillation with thermal sources. In this case, the local nanoscale heat transfer from illuminated nanoparticles to the surrounding liquid can selectively perturb the hydrogen bonding network of simple liquids. These light-generated steam processes have direct applications in solar energy harvesting, where the goal is to produce steam directly for a variety of applications. [3]

[1]O. Neumann, A. S. Urban, J. Day, S. Lal, P. Nordlander, and N. J. Halas, ACS Nano 7, 42-49 (2013).

[2] N. J. Hogan, A. S. Urban, C. Ayala-Orozco, A. Pimpinelli, P. Nordlander and N. J. Halas, Nano Letters 14, 4640-4645 (2014).

[3] O. Neumann, C. Feronti, A. D. Neumann, A. Dong, K. Schell, B. Lu, E. Kim, M. Quinn, S. Thompson, Nl Grady, P. Nordlander, M. Oden, and N. J. Halas, Proceedings of the National Academy of Sciences, 110, 11677-11681 (2013).