- William Euler
- Beaupre 474B
- Professor of Chemistry
- (401) 874-5090
- Ph.D. Florida State University
Our primary studies are centered on the properties of thin films and interfacial effects. In particular, understanding the properties of materials used in chemical sensors drives our research. We use a variety of spectroscopic tools in our investigations including UV-vis-NIR, FTIR, Raman, and fluorescence spectroscopies. Two problems are currently of interest: use of xanthene dyes as chemical sensors and controlling the surface structure of polymer thin films.
Xanthene dyes are a class of fluorescent materials that are readily available and commonly used as laser dyes. These compounds have strong absorbance in the visible region of the spectrum and are highly emissive, with many having quantum yields in solution approaching 1. When cast as thin films the properties of these dyes change, with a typical response being a significant quenching of the fluorescent when the films are more than a few nm thick. Further, the underlying substrate can also influence the photophysics of the dye. By exploiting the interfacial structure of the dye, the fluorescent response can be used as a sensor for explosives, biomarkers, and other analytes.
Spin casting is a common method for creating smooth polymer films with thicknesses from hundreds of nanometers to tens of microns. Under certain circumstances, a spin-cast film can result in a structured surface that has the form of periodic wrinkles. We have found that the wrinkles have wavelengths on the order of tens of microns and amplitudes of tens of nanometers. The wrinkle pattern is influenced by the concentration of the polymer solution used in spin-casting, the angular velocity used, and the polymer molecular weight. The surface structure, especially the possibility of introducing quantum confinement, can be used to influence the properties of surface deposited species such as sensing dyes.
2014 Arts and Sciences Administrative Excellence Award