Measurement of self-diffusion coefficient of asphaltene in pyridine by pulsed field gradient spin-echo ¹H NMR

Measurement of self-diffusion coefficient of asphaltene in pyridine is presented. The measurement is performed by pulsed field gradient spin-echo ¹H nuclear magnetic resonance (PFG-¹H NMR. The diffusion coefficient provides information concerning molecular size and aggregation states. The PFG ¹H NMR measurements are most suitable as it is possible to determine the displacement of proton in the time interval between the two gradient pulses applied in the pulse sequence.