(349a) Continuous Synthesis of Nano Structures

Chemically synthesized nano structured materials are being considered for active elements in many device applications, including photovoltaics, displays, and bio-chem sensing.  In order to realize the promise of these techniques, it will be critical to have an efficient, reproducible synthesis technique of the nanostructures.  Currently, nanoparticles are synthesized in a batch mode in small volumes, which is appropriate for studying the fundamental properties of nanosized structures and for developing proof of principle device structures; but batch synthesis suffers from variations of size distribution and properties from batch to batch.  Continuous flow reactors based on microfluidics (microreactors) integrated with heaters and fluid control elements offer a solution to these problems as well as expand the synthesis space by providing easier access to high pressure and temperature conditions. Moreover, integrating multiple reaction steps enable the synthesis of complex nanostructures, such as core shell nanoparticles, polymer particles loaded with quantum dots, and oxides decorated with metal nanoparticles.  Examples include the synthesis of InP quantum dot cores overcoated with ZnS for applications in the visible spectrum, micron sized polymer particles loaded with CdSe/ZnS quntumdots, and silica particles decorated with gold nanowires for surface enhanced Raman sensing.