(3cx) Metal Nanoparticles for Advanced Technologies: A High-Throughput Approach to Study Structural Degrees of Freedom | AIChE

(3cx) Metal Nanoparticles for Advanced Technologies: A High-Throughput Approach to Study Structural Degrees of Freedom

Authors 

Michalak, W. D. - Presenter, Carnegie Mellon University


Metal nanoparticles on structured supports are used in many technological applications such as biosensing, energy harvesting, catalysis, and electronics.  In every case, the functions and properties of the metallic nanostructures depend on their composition and structure (i.e. size, shape, and spatial distribution).  Challenges to using metal nanoparticles in these applications are the difficulties of optimizing the structure-property functionality over a large structural domain.  To accelerate optimization, it is desirable to use high-throughput/combinatorial methods; however, the most common applications of high-throughput methods in the physical and material sciences focus almost exclusively on compositional space. Therefore, a practical approach to create and study metal nanostructures in a high-throughput manner would greatly accelerate the understanding of their structure-sensitive properties.

In my graduate studies at Carnegie Mellon University with Profs. Andrew Gellman and James Miller, I discovered a novel approach to create a morphological gradient of metal particles in a repeatable and controlled manner, which extends directly to high-throughput fabrication and characterization of structure-sensitive properties because it allows for simultaneous fabrication over a relatively large spatial domain. The method is based on inducing precursor thin films to dewet from a substrate through spinodal dewetting.  Spinodal dewetting allows the creation of particles that have well-defined structural properties by adjusting a few variables: initial film thickness, annealing temperature and annealing time.  The morphologies of the particles were characterized using scanning tunneling and atomic force microscopies, and hydrodynamic stability and integral geometry theories to confirm the dewetting mechanism.  In addition, the hydrodynamic instability theory provides a connection to the thermophysical properties of the system.  The dewetting approach is general to any metal/ceramic support system and provides an alternative, inexpensive, and robust means to rapidly create metal nanostructures.  It shows promise for large scale production of the metal structures, as well as understanding basic material properties.

I am currently working with Prof. Gabor Somorjai at the University of California, Berkeley as a post-doctoral researcher.  I continue to study the novel functionalities of metal nanoparticles as a function of size and shape using state-of-the-art experimental techniques.  My initial research goals as a faculty member include the rational design of renewable-energy and clean-energy systems.  I will focus on molecular-level understanding and high-throughput methodologies to accelerate development.  The experience I gained during my graduate work, and the experience I continue to gain as a postdoc, position me to make significant contributions in a faculty position.