Date of Award
Master of Science (MS)
Prof. Nikolay Dimitrov
A fluorescent chromophore, hereby designated as cyanine dye, has been bound to generated zinc oxide nanoparticles. It has been shown that the material not only retains the characteristic absorption peak of the native chromophore, but it also continues to fluoresce with comparable intensity. The binding occurs through a Zn – O2C bridge, which allows for vibrational relaxation as the dye heats up, yet also preserves the optical properties of the dye. This bond linkage can be observed from the comparison of FT-IR spectra of the nanoparticles and the native dye, designated by a shift in one of the peaks at 1730 cm-1. The nanoparticle-dye material has been characterized through a variety of techniques, including differential scanning calorimetry, thermal gravimetric analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The thermal stability of the dye was improved from a significant level of decomposition by 200 °C to nearly no loss of mass at 350 °C. It proved impossible to record a Raman spectrum of the dye itself, as the laser degraded the dye before measurements could be taken, but the thermal stabilization of the nanomaterial also allowed the dye to be examined by Raman spectroscopy without decomposition. Both the dye and the nanomaterial exhibit the same Stokes shift, from the 819 nm absorbance peak to an 850-nm emission peak.
Hughes, Brendan P., "A Thermally Stabilized Fluorescent Organic Chromophore" (2017). Graduate Dissertations and Theses. 50.