DIPC International Physics Colloquia (DIPC)

Thursday 31.5.2018 17:30

Plasmonics: From Stained Glass to Sustainability and Societal Impact

Naomi Halas

Rice University, Houston, Texas, USA

Metallic nanoparticles, used since antiquity to impart intense, vibrant color into materials, then brought to scientific attention in the 19th century as "Faraday's colloid", have more recently become a central tool in the innovative manipulation of light. While the scientific foundation of this field was built on the optical properties of noble and coinage metals, more recently we have begun to question whether the same, or similar properties can also be realized in far more sustainable materials. Aluminum, the most abundant metal on our planet, can support high-quality plasmonic properties spanning the UV-to-IR region of the spectrum. Coupling a plasmonic nanoantenna directly to catalytic nanoparticles transforms the entire complex into an efficient light-controlled catalyst capable of driving chemical reactions under surprisingly mild, low temperature conditions. Nanoscale graphene, when reduced to the molecular limit, sustains many plasmonic properties but introduces new ones such as single-electron color switching, which can be utilized in unique electrochromic devices. We have previously introduced photothermal effects for biomedical therapeutics; now, years after their initial demonstration, this approach is being utilized in human trials for the precise and highly localized ablation of cancerous regions of the prostate, eliminating the highly deleterious side effects characteristic of conventional prostate cancer therapies. Photothermal effects can also be harvested for sustainability applications, which we have most recently demonstrated in an off-grid solar thermal desalination system that transforms membrane distillation into a scalable water purification process.

Naomi Halas is the Stanley C. Moore Professor of Electrical and Computer Engineering at Rice University, where she also holds faculty appointments in the Departments of Physics, Chemistry, and Bioengineering. She is best known as the first person to demonstrate that controlling the shape of metallic nanoparticles determines their color, inventing a family of nanoparticles with resonances spanning the visible and infrared regions of the spectrum. She pursues fundamental studies of plasmonic and nanophotonic systems and their applications in biomedicine, optoelectronics, photocatalysis, chemical sensing and, most recently, solar steam generation with applications in off-grid water treatment. She is author of more than 300 refereed publications, has more than 15 issued patents, and has presented more than 500 invited talks. Dr. Halas is a founder of Nanospectra Biosciences, a Houston-based company developing ultralocalized photothermal therapies for cancer, and Syzygy Plasmonics, a company developing photocatalysts for facilitating chemical reactions at temperatures far below current industrial processes. She has been awarded the APS Frank Isakson Prize for Optical Effects in Solids, the R. W. Wood Prize of the OSA, and the APS Julius Lilienfeld Prize for outstanding contributions to physics by a single individual who also has exceptional skills in lecturing to diverse audiences. Halas has been elected to the National Academy of Engineering, the National Academy of Sciences, and the American Academy of Arts and Sciences, and is a fellow of the National Academy of Inventors (all U. S.).