Date: 26 February, 2020
Time: 11:00 AM – 12:00PM
Location: Building 4, Room 125
Dr. Wissam Nabil Iali
Department of Chemistry, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran, Saudi Arabia
Nuclear magnetic resonance spectroscopy (NMR) is one of the most powerful method to analyse and discover molecules. However, the low sensitivity of this technique acts to limit its applicability, while adding substantially to cost. This problem arises from the very low value of the nuclear polarisation from which the NMR signal directly derives. This polarisation depends on the external magnetic field B0 and on the inverse of temperature. While the biggest world NMR apparatuses well beyond 21T, even at this magnetic field, the nuclear polarisation is only 7.10-5 for 1H at room temperature. As consequence of the sensitivity issue, NMR cannot detect molecules at low concentration such as trace product contaminant that can be found in water, petroleum samples, etc. In more recent years, the sensitivity of NMR has been improved by the concept of molecular hyperpolarisation that consists in artificially and transiently increasing the nuclear spin polarisation from the thermal equilibrium. This is performed by polarisation transfer from a more ordered system, such as photons (optical pumping), electrons (e.g. DNP) or purely singlet state nuclear spin order systems (parahydrogen = pH2).