Nuclear spin relaxation

The review covers the progress in the field of NMR relaxation in fluids primarily during 2019. Since the topic is returning to this volume SPR after a break of a few years, some highlights of the relaxation literature from the period 2014–18 are mentioned. The emphasis is on comparatively simple liquids and solutions of physico-chemical and chemical interest, as in previous periods, but selected biophysics-related topics (including some work on relaxation in solid biomaterials) and relaxation-related studies on more complex systems (macromolecular solutions, liquid crystalline systems, glassy and porous materials) are also covered. Section 2 of the chapter is concerned with general, physical and experimental aspects of nuclear spin relaxation, while Section 3 is concentrated on applications.