Dynamic nuclear polarization in suspensions of liquid asphalts in weak magnetic field


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Akay C. , Yalçıner A., Ovalıoğlu H. , Çimenoğlu M. A.

ARI Bulletin of the Technical University of Istanbul , vol.51, pp.141-144, 2014 (Refereed Journals of Other Institutions)

  • Publication Type: Article / Article
  • Volume: 51
  • Publication Date: 2014
  • Doi Number: 10.1007/s007770050046
  • Title of Journal : ARI Bulletin of the Technical University of Istanbul
  • Page Numbers: pp.141-144

Abstract

Nuclear Magnetic Resonance (NMR) and the Overhauser Effect (OE) type Dynamic Nuclear Polarization (DNP) were used to study MC-30 liquid asphalt in a weak magnetic field of 1.437 mT. Intermolecular spin-spin interactions occur between diffusing nuclear spins in the suspending fluid medium and unpaired electron spin in the liquid asphalt. Benzene, toluene, quinoline, pyridine, chlorobenzene, tetralin, nitrobenzene, ethylbenzene, and thiophene were used as the suspending fluid medium. The EPR spectrum of the liquid asphalt MC-30 is a single line of Gaussian shape in weak field. Some solvents can strip the natural resins from the asphaltene surface so that effectively closer contact can occur. The solvents which have highly polarizable and chemically active regions, and have chlorine or nitrogen atoms, can form stereospecific transient complexations.