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Chapter 3

3. Characterization Ofemuisions by NMR

This chapter focuses on the characterization of diluted bitumen emulsion
properties from nuclear magnetic resonance (NMR) measurements. Sections 3.1
- 3.4 first introduce MNR techniques; then show how to characterize diluted
bitumen emulsion using these methods. The rest part of the chapter discusses
experimental procedures and results.

3.1. Introduction

NMR spectroscopy is based on the fact that some nuclei process a
permanent nuclear magnetic moment. Some nuclei, such as protons, have a
permanent magnetic moment p. When a steady uniform magnetic field B₀ is
applied on these nuclei, they take certain stated which correspond to distinct
energy levels. The magnetic moment p precesses around the direction of B₀ at
the Larmor frequency wɑ = γB₀, where y is a constant. The nuclei exhibit net
magnetization M in the direction of B₀. If a radio frequency (rf) pulse of a second
magnetic field Bi orthogonal to Bo is applied, the net magnetization is rotated to
an extent (typically 90^o or 180^o) that depends on the duration of the pulse. After
the rf pulse, M will relax and finally reach equilibrium state. Relaxation of M can be
measured from the spins (precessing protons), either in the direction of Bo
(longitude magnetization), or transverse plane (transverse magnetization).

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