Nanotechnology in the Environment: Understanding and Exploiting the Wet/Dry Interface
Victor Kreible Professor of Chemistry and Engineering
Nanotechnology is no longer an emerging area of study. It is now a well-established research topic that spans nearly all scientific and engineering disciplines, as well as a broad technology sector with many tangible commercial products. Given its position as both a powerful driver of novel science and technologies, the intersection of nanotechnology and environmental research presents many interesting challenges and opportunities which will be illustrated in this talk. Nanotechnology is based on manipulating and applying materials with dimensions between 1 and 100 nanometers; at this scale, materials exhibit special optical, magnetic and chemical properties which are often size-tunable. Applications of nanotechnology exploit these novel material features and thus provide fresh approaches to classic problems such as the efficient treatment of water and the remediation of contaminants from matrices as diverse as soils and aquifers. While these applications use nanomaterials in contained settings, they make it possible to envision the widespread distribution of nanomaterials into our environment.
The fate and implications of such exposures is a fascinating question. Conventionally specialized materials such as silicon or cerium oxide interact with biological and environmental systems as bulk solids. The small size of nanomaterials means that these materials can now move more readily in the environment or the body, and that they can interact with biological systems. They in effect create a highly active interface between 'dry' typically crystalline solids and the complex 'wet' environment. This can be fully exploited in both medicine and catalysis as will be illustrated by cerium oxide. It can also create challenges if the wet/dry interface leads to material dissolution and the release of metal ions. As an example silver nanoparticles exhibit more rapid and extensive dissolution as their dimensions shrink; because their toxicity is the result of silver ions released in dissolution, this can have consequences for their long-term impacts. Much of this size-dependent dissolution, and as a result anti-microbial activity, can be anticipated based on fundamental models of solid state dissolution. It can also be manipulated through surface engineering which of practical importance to the safe and efficient use of silver nanoparticles as disinfection agents.
Professor Colvin is the Victor Kreible Professor of Chemistry and Engineering at Brown University and Director of its Biomedical Engineering program. Her research explores how nanoscale particles interact with the environment and living systems. She meshes both novel synthetic chemistry with quantitative imaging and spectroscopy to study how the physical dimensions of material affect their properties and interaction with complex organisms. This fundamental knowledge lays a foundation for her group’s development of innovative technologies which use novel nanoscale materials in both medical and environmental applications. Examples include the use of magnetic nanoparticles for water treatment in off-grid settings as well as catalytic anti-oxidants for mediating the foreign body response of implanted medical devices. She has published over 150 peer-reviewed papers, holds five patents and is the recipient of numerous awards including the 2015 Sustainable Nanotechnology award and the 2013 Chemistry of Materials Highly Cited Investigator. She received her undergraduate degree in Chemistry and Physics from Stanford University in 1988 and her PhD in Chemistry from U. C. Berkeley in 1994.