Nuclear Magnetic Relaxation Mapping of Spin Relaxation in Electrically Stressed Glycerol

Abstract

This work discusses nuclear magnetic relaxation effects in glycerol subject to a strong electric field. The methods used are 1.5 T magnetic resonance imaging (MRI), referenced by 9.4 T nuclear magnetic resonance (NMR). While MRI allows a glycerol probe to be sampled with a high voltage (HV) of 16 kV applied to the probe, NMR provides precise molecular data from the sample, but the sample cannot be tested under HV. Using MRI, the recording of magnetic relaxation times was possible while HV was applied to the glycerol. NMR spectroscopy was used to confirm that MRI provides a reasonably accurate estimation of temperature. The applied HV was observed to have a negligible effect on the spin–lattice relaxation time T 1 , which represents the energy release to the thermal bath or system enthalpy. In contrast to that, the spin–spin relaxation time T 2 , which does represent the local entropy of the system, shows a lower response to temperature while the liquid is electrically stressed. These observations point toward a proton population in electrically stressed glycerol that is more mobile than that found in the bulk, an observation that is in agreement with previously published results for water.

Status and Outlook of Oil Field Chemistry-Assisted Analysis during the Energy Transition Period

“…232,233 Nuclear spin relaxes under a specific pulse sequence to generate the NMR response. 234,235 The responses are initiated at the atom level because of the hydrogen spin angular momentum, proportional to the magnetic field strength. At the macroscale level, the exerted external magnetic field aligned the magnetic moments of hydrogen from the random distribution or the nonisotropic distributions.…”

“…Low-field NMR technology has also been widely applied in the oil and gas industry. , NMR technology has advantages over others because of its nondestructiveness to the samples tested. , Nuclear spin relaxes under a specific pulse sequence to generate the NMR response. , The responses are initiated at the atom level because of the hydrogen spin angular momentum, proportional to the magnetic field strength. At the macroscale level, the exerted external magnetic field aligned the magnetic moments of hydrogen from the random distribution or the nonisotropic distributions. , The nuclear Larmor frequency is proportional to the magnetic strength and the gyromagnetic ratio .…”