Presentation Title

Investigating Motion via Deuterium Line shape simulations

Start Date

November 2016

End Date

November 2016

Location

HUB 302-11

Type of Presentation

Poster

Abstract

Deuterium is a nucleus which is Nuclear Magnetic Resonance (NMR) active and has a spin quantum number of 1 which gives rise to a non-spherically symmetric nuclear charge density. The distortion of the charge density is the cause of deuterium’s quadrupole moment which interacts with the electrical field gradients around the nucleus. This quadrupolar interaction dominates the solid state deuterium NMR Spectra. Deuterium line shapes which are called Pake Patterns are very sensitive to molecular motion and provide valuable information.

We are investigating the molecular motion of D2O in Gypsum. The presence of water in Gypsum causes it to have fire retardants properties. We are using the algorithms in Dr. Alan Benesi’s new book “A Primer in NMR Theory with Calculations in Mathematica” in simulating the rates of rotation in deuterium nuclei for D2O in gypsum. Our results indicate that the D2O in Gypsum at 220C performs a 2 site hop about the bisector angle of 54.80 at the rate of 107Hz or higher. The Quadrupole Coupling Constant (QCC) and the asymmetry parameter (η), used are 216KHz and 0.15 respectively. At 00C the deuterium nuclei move similarly with nearly the same values for QCC and η. At -250C, the line shape shows some broadening and can be fitted with fast regime motion with a QCC of 223kHz and η of 0.13. Once we simulate deuterium Pake Patterns at many temperatures we will use an Arrhenius plot to extract the activation energy for this motion.

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Nov 12th, 1:00 PM Nov 12th, 2:00 PM

Investigating Motion via Deuterium Line shape simulations

HUB 302-11

Deuterium is a nucleus which is Nuclear Magnetic Resonance (NMR) active and has a spin quantum number of 1 which gives rise to a non-spherically symmetric nuclear charge density. The distortion of the charge density is the cause of deuterium’s quadrupole moment which interacts with the electrical field gradients around the nucleus. This quadrupolar interaction dominates the solid state deuterium NMR Spectra. Deuterium line shapes which are called Pake Patterns are very sensitive to molecular motion and provide valuable information.

We are investigating the molecular motion of D2O in Gypsum. The presence of water in Gypsum causes it to have fire retardants properties. We are using the algorithms in Dr. Alan Benesi’s new book “A Primer in NMR Theory with Calculations in Mathematica” in simulating the rates of rotation in deuterium nuclei for D2O in gypsum. Our results indicate that the D2O in Gypsum at 220C performs a 2 site hop about the bisector angle of 54.80 at the rate of 107Hz or higher. The Quadrupole Coupling Constant (QCC) and the asymmetry parameter (η), used are 216KHz and 0.15 respectively. At 00C the deuterium nuclei move similarly with nearly the same values for QCC and η. At -250C, the line shape shows some broadening and can be fitted with fast regime motion with a QCC of 223kHz and η of 0.13. Once we simulate deuterium Pake Patterns at many temperatures we will use an Arrhenius plot to extract the activation energy for this motion.