Research Symposium

BIO

Daphne Broerman is from Jacksonville, Florida, and is currently a 2nd year chemistry major. After graduating from FSU, Daphne hopes to attend graduate school and continue working in research.

Functionalized Materials as Polarizing Agents for Dynamic Nuclear Polarization in Liquids

Abstract

Dynamic Nuclear Polarization (DNP) describes a method of transferring the spin polarization of unpaired electron spins on organic radicals to neighboring nuclear spins through the usage of microwave irradiation. DNP has been developed to enhance the sensitivity of Nuclear Magnetic Resonance (NMR) spectroscopy. The primary goal of our experiment was to develop hyperpolarized NMR of mixed-phase materials. To do this, we prepared functionalized silica materials that contain a radical covalently bonded to the surface that is able to locally hyperpolarize the liquid in the proximity of the surface of the material. To prepare the samples for our experiment, we ground up TEMPO on silica gel (SiTM) beads into a fine powder, washed this powder to release any remains of the radical, and suspended the washed powder into various concentrations of different solvents. To obtain the spectra of these samples we have utilized a benchtop Electron Paramagnetic Resonance (EPR) spectrometer so that we are able to analyze the hyperfine coupling present in these heterogeneous mixtures. This methodology has shown that these mixed-phase materials are useful polarizing agents that can be utilized in DNP. We have found that silica is a promising substrate that could be explored further in future DNP experiments of heterogeneous systems.

Keywords: Chemistry, Magnetic Resonance