Portal de Periódicos da CAPES

NMR diffusion and flow measurements and an introduction to spin phase graphing

1978; IOP Publishing; Volume: 11; Issue: 4 Linguagem: Inglês

10.1088/0022-3735/11/4/001

2051-5685

J. R. Singer,

Advanced NMR Techniques and Applications

Diffusion and flow can be measured very delicately and accurately using an NMR system. The essence of the method is that motion of magnetic nuclei in a magnetic field and a magnetic gradient results in those nuclei changing their Larmor precession frequency and their phase angle in the field. Since NMR can be set up to measure the number of nuclei at specific phase angles, the motion of groups of nuclei can be determined very accurately. Self-diffusion of molecules was first measured by Hahn in 1950. Self-diffusion of molecules and flow of molecules can be separated in an NMR measurement as was shown by Carr and Purcell in 1954. This review describes some techniques of NMR diffusion and flow measurements, and a method of plotting phase angles of isochromatic spin groups for theoretical analyses and simulations of NMR experiments.