Description:

The Department of Materials Science and Engineering welcomes you to its 2015 Fall Colloquium Series.

Location: Tech L361, 4:00pm

Stephen McIntosh
Professor
Lehigh University

Functional Materials for Energy Systems: From Ionic Transport to Biomineralization
The McIntosh group focuses on the development of functional materials in energy systems. As opposed to structural materials, functional materials interact with their environment to provide a useful function, be it ionic transport and catalysis in a fuel cell, or light harvesting in a solar cell. In this talk, McIntosh will focus on two specific areas: the use of in-situ powder neutron diffraction techniques to probe ionic transport in materials for solid oxide fuel cells, and biomineralization as a route to the green synthesis of semiconductor quantum dots.
The promise of direct and efficient conversion of chemical to electrical energy makes fuel cell development an area of great technological interest. Solid Oxide Fuel Cells (SOFCs) are one of the most promising technologies to meet this goal. However the current high operating temperature (typically > 700 oC) is a barrier to wide-scale adoption of the technology. A significant barrier to progress is a lack of experimental techniques that can probe the materials properties under working conditions. In-situ neutron diffraction can reveal information relating to phase transition, order-disorder phenomenon, and the number, location and anisotropic displacement of oxygen vacancies in crystalline oxides over a wide variety of operating conditions. Analysis of this data enables visualization of preferred transport pathways in the material. We couple this with measurements of outer surface composition and surface kinetics to interpret the performance of fuel cell electrodes.
Biomineralization is the process by which living organisms form minerals. The majority of prior biomineralization studies have focused on the production of structural materials, such as bone and shells, similar to those found in nature. The McIntosh group is part of a collaborative effort to utilize biomineralization to produce functional materials. Results will be presented demonstrating the efficacy of this approach for the size controlled green synthesis of semiconductor quantum dots of a range of compositions.

Biography: Steven McIntosh is the Class of ‘61 Associate Professor of Chemical and Biomolecular Engineering at Lehigh University. He received his Bachelor of Engineering from the University of Edinburgh, Scotland, and his MS and PhD in Chemical Engineering from the University of Pennsylvania. He spent a postdoctoral period in the Inorganic Materials Science group of Prof. Henny Bouwmeester at the University of Twente, NL. Dr. McIntosh was an assistant professor at the University of Virginia from 2006 to 2010, prior to joining the faculty at Lehigh University in Fall 2010.
He was awarded a Marie Curie Intra-European Postdoctoral Fellowship from the European Union in 2004 and received a National Science Foundation CAREER award in 2007. He is an associate editor for RSC Advances and editor for the RSC Specialist Periodical Reports Electrochemistry.