NANOSCALE: Shape Control in Nanoscale Crystallization Processes

Tufts University, Medford MA

Investigators

Abstract

Abstract CTS-9986545 D. Kaplan, Tufts University The goal of this research is to use principles of biomimetics to control the shape, chirality and morphology of nanoscale inorganic crystals. Reactions will be carried out in confined geometries (thin films or reverse micelles), taking advantage of template chemistry, organized water layers, and chirality of the template. Peptides specific for inhibiting crystal growth at surfaces will be selected via combinatorial methods and used in the experiments to assess their ability to modulate control of crystal shape. Calcium carbonate and sodium chlorate will be used as the model salt systems. These experimental strategies will help us begin to mimic biomineralization processes, natural processes that are adept at precise control of nanoscale inorganic crystallization processes; systems useful to emulate in vitro. Well-defined monolayers will be formed with amino acid-terminated surfactants in which head group chemistry, based on the specific amino acid, and chirality, through the use of L- or D-amino acids, can be controlled. The surfactants will be used in reverse micellar and thin film formats as confined geometries. The chiral organic surfactant head groups will be used to understand the relationship between chirality and inorganic crystal morphology. Phage display will be used for combinatorial selection of peptides as specific inhibitors of crystal surfaces. The outcome of the studies will be new options to modulate crystal shape through combinations of template chemistry, template chirality, crystallization in confined geometries and the presence of selective inhibitory peptides. The unique combination of experimental tools that we plan to use will provide new insight into fundamental processes of nanoparticle crystallization and lead to a better understanding of how to control the shape of these nanoscale sized inorganic crystals. Shape and morphology control of crystallization processes are significant for a wide range of electronics, optics and pharmaceutical applications.