0504105_McGee

1. Enhanced Photostability of Azo-dye Infused Nanoporous SilicaDavid J. McGee (Drew University) and Howard E. Katz (Johns Hopkins University)DMR-0504105 Porous silica impregnated with active nonlinear optical chromophore/polymer blends is a promising platform for patterned deposition of optical materials for use in integrated optical devices. In this work, a nanoporous silica matrix platform was generated through sol-gel chemistry by the use of N,N-dimethylformamide as a relatively nonvolatile porogen. The silica monoliths are optically transparent, 58% porous, and mechanically robust. Conventional guest-host polymer blends are susceptible to optically-induced bleaching, limiting their use in applications. Bleaching is characterized by the photostability figure-of-merit (FOM), which is a measure of chromophore lifetime in the presence of laser irradiation. Previous research suggests encapsulation of the chromophores by nanoporous silica may provide enhanced stability against optically induced bleaching. When compared with conventional guest-host polymer blends containing azo-dye chromophores, the impregnated silica monolith exhibits a five-fold improvement in photostability figure of merit. Transparent silica monolith infused with nonlinear optical dye Disperse Red 1. Edge length of grid squares is 6 mm.

2. Collaborative research: Linking primarily undergraduate institutions with research universitiesDavid J. McGee (Drew University), Padma Gopalan (University of Wisconsin-Madison)Volkmar Dierolf and Ivan Biaggio (Lehigh University) DMR-0504105 Drew University is a primarily undergraduate institution (PUI) with a strong history of faculty mentored undergraduate research. Through the NSF-RUI program, Drew professor of physics David McGee has established a photonics lab for the study of emerging organic electro-optic materials. To complement this, Drew has established the Drew Summer Science Institute which provides housing, stipends, and a programmatic framework. To give Drew students broader exposure to advanced research, collaborations with University of Wisconsin-Madison and Lehigh University were established. Drew physics and chemistry students work 1 summer at Drew and 1 summer at Wisconsin/Lehigh, with the project continuing during the intervening academic year as Honors/Independent study. At University of Wisconsin, Drew students have participated in the NSF-REU program at the Nanoscale Science and Engineering Center (NSEC). At Lehigh University, Drew students have participated in the physics department NSF-REU program and have worked in Lehigh’s Center for Optical Technology(COT). Since 2005, ten Drew students have participated in this joint research program. By connecting two summers of research with the academic year, undergraduate students can participate as co-authors on peer-reviewed publications. Two recent publications with Drew students J. Mykietyn, N. Woodward, and A. Caruso are: V. Campbell, P. Paoprasert, J. Mykietyn, I. In, D.J. McGee, and P. Gopalan, Journal of Polymer Science Part A, 45, 3166, (2007). V. Campbell, I. In, D.J. McGee, N. Woodward, A. Caruso, and P. Gopalan, Macromolecules, 39, 957, (2006). Drew-Lehigh collaboration: from left- Pavel Capek (Lehigh postdoctoral fellow), Nate Woodward, Ethan Marsh, Dave Newby (Drew undergraduates), Naveen Jha (Lehigh graduate student)