Eco-Nano: The Impact of Engineered Nanomaterials on the Environment

Traditionally, nanotechnology has been motivated by the growing importance of very small (d < 50nm) computational and optical elements in diverse technologies. However, this length scale is also an important and powerful one for living systems. At Rice, we believe that the interface between the ‘dry' side of inorganic nanostructures and the ‘wet' side of biology offers enormous opportunities for medicine, environmental technologies, as well as entirely new types of nanomaterials. As part of our work on the potential biological applications, we also consider the unintended environmental implications of water soluble nanomaterials. Given the breadth of nanomaterial systems, we use a carefully selected group of model nanoparticles in our studies and focus on natural processes that occur in aqueous systems. We characterize the size and surface-dependent transport, fate and facilitated contaminant transport of these engineered nanomaterials. Models from larger colloidal particles can be extended into the nanometer size regime in some cases, while in others entirely new phenomena present themselves. We also consider biological interactions of nanoparticles and specifically address the interactions of a classic nanomaterial, C₆₀, with cellular systems. While the water-suspendable nano-C₆₀ nanocrystal is apparently cytotoxic to various cell lines, the closely related fully hydroxylated, C₆₀(OH)₂₄, is non-toxic, thus producing no cellular response. Similarly, we have also found that functionalized single-walled carbon nanotubes are non-toxic to cells in culture. More specifically, as the functionalization density of the SWNT increases, the nanotube becomes more inert to cultures.