Considerations in evaluating the physicochemical properties and transformations of inorganic nanoparticles in water

Nanomaterials and the technologies they enable are often presented as important innovations that will play a critical role in solving problems that range from energy, water and food supply to improved medical treatments. Ironically, many of the more 'media-genic' nanomaterial-enabled products making their way to consumers address considerably more humble objectives, such as making socks cleaner or reducing wrinkles. This very broad range of nanomaterial applications suggests an equally broad range of scenarios for nanomaterial use, incorporation into products and disposal, which characterizes the lifecycle of these novel materials. Nanomaterials introduced to environmental and physiological systems will most likely undergo significant transformations, complicating any effort to related underlying nanoparticle with observed effects. This article discusses several dimensions of nanoparticle reactivity and the potential for environmental transformation of the nanoparticle properties, in particular focusing on metallic nanoparticles.