# Project Summary

Research objective

## Intellectual Merit

The scope of my investigation is limited to the synthesis of colloidal metal nanocrystals, particularly silver (Ag). The polyol synthesis is a popular solution-phase synthesis of Ag nanocrystals (Skrabalak 2007). The typical reaction temperature is 150$$^{\circ}$$C. In the polyol synthesis, ethylene glycol acts as both the solvent and the reducing agent. The source of Ag is from silver nitrate ($$AgNO_3$$) that is dissolved in ethylene glycol. Ag seeds may be added in order to disentangle growth from nucleation, enhancing control of nanocrystal size and shape. Structure-directing agents, typically polyvinylpyrrolidone (PVP), are added to prevent aggregation of nanocrystals and to promote the formation of {100}-faceted nanocrystals. The reaction conditions such as temperature, the concentration of $$AgNO_3$$, and the molar ratio of PVP to $$AgNO_3$$ is critical to the formation of different nanocrystal shapes. These shapes can range from cubes (Xia 2012, Zhang 2010), triangular plates (Lofton 2005, Liu 2012), and five-fold twinned pentagonal wires (Zhu 2011, Zhang 2008, Sun 2002). It was hypothesized that PVP promotes the formation of {100} facets by preferentially binding to {100} facets over {111} facets (Xia 2012, Sun 2002), also known as facet specific adsorption.