1D and 2D Electron Spin Resonance Imaging (ESRI) of Transport and Degradation Processes in Polymers

Abstract

Paul Lauterbur was the first to propose, in his notebook entry of 2 September 1971, the use of magnetic field gradients in order to “tell exactly where an NMR signal came from”; his first proton density map appeared soon afterwards (Lauterbur, 1973). He named the technique zeutmatography, from the Greek word for “joining together”, meaning to join the magnetic field gradient and the corresponding radiofrequency in a nuclear magnetic resonance (NMR) experiment. This connection allowed the encoding of spatial information in the NMR spectra. The use of magnetic field gradients to separate the resonant frequencies corresponding to the various spatial elements led to the development of NMR imaging (NMRJ) or, in current language, magnetic resonance imaging (MRI). Against a back-drop of general skepticism, NMRI has blossomed into an essential, and routine, diagnostic procedure in medicine that provides an image of previously hidden anatomic parts. Applications of NMRI to Materials Science and other important disciplines, although not as dramatic as the medical applications, are extensive, ubiquitous, steadily developing, and well documented (Blumler et al., 1998). The wonderful story on the discovery of NMR imaging has been told recently (Kevles, 1997).