Recent Research from Prof. Van Keuren

Structure of cocrystals, diagram of oriented ribbons, and graph showing colored transfer curves for various temperatures — Figure from one recent publication, showing the PTZ-TCNQ cocrystals, organic field effect transistors, and transfer curves

ISMSM Faculty Member Edward Van Keuren has had two papers recently published. The first is the result of a collaboration of researchers in Van Keuren’s lab and the ISM, along with other Georgetown faculty and researchers from George Mason and Howard University. “Charge Transport through Superexchange in Phenothiazine – 7,7,8,8-Tetracyanoquinodimethane (PTZ-TCNQ) Cocrystal Microribbon FETs Grown Using Evaporative Alignment ” was published online November 22^nd in ACS Applied Electronic Materials. The research deals with the optical and electronic characterization of the charge transfer cocrystal PTZ-TCNQ. An evaporative alignment method was used to create oriented ribbons of PTZ-TCNQ which were made into organic field effect transistors. Transfer curves of the devices showed primarily electron conduction, and temperature-dependent measurements of the mobility indicated a superexchange mediated hopping transport.

Additionally, Prof. Van Keuren was involved in research that included collaborators from Georgetown’s Department of Chemistry and Department of Oncology. “Molecular Parameters Promoting High Relaxivity in Cluster-Nanocarrier Magnetic Resonance Imaging Contrast Agents ” was published in the 14^th volume of ACS Applied Materials and Interfaces and investigates the water exchange rates of two clusters and corresponding cluster-nanocarriers to determine the mechanism of relaxivity.

Graphs of water exchange, and diagrams of a hydrophobic and hydrophilic carrier, with colored dots to showing position of molecules in carrier. — Figure from other recent publication, highlighting the water exchange rates and carriers.