8704334 NMR imaging method and apparatus therefor

Abstract

Infrared spectra and electron spin resonance (e.s.r.) spectra of aluminium, silicon and titanium oxides have been investigated. Upon evacuation at elevated temperatures the infrared spectra of all oxides investigated show absorption bands of surface hydroxyl groups, while e.s.r. signals have been detected only in the spectra of aluminium and titanium oxides. Infrared spectra resulting from adsorption of vapours of n-hexane, benzene, diethyl ether, acetone, diethylenetriamine, pyridine and acetic acid on these oxides and e.s.r. spectra of adsorbed anthracene have been determined. A considerable difference has been demonstrated in the nature of interaction of oxygen- and nitrogen-containing molecules, as well as anthracene molecules, with the surfaces of (1) silicon dioxide and (2) aluminium and titanium oxides. Depending on the electronic structure of the molecules adsorbed on aluminium oxide and titanium dioxide, surface chemical compounds of different types are formed in several cases. Anthracene is chemisorbed on aluminium oxide and titanium dioxide, this being attended by charge transfer and emergence of ion radicals, causing an e.s.r. signal to appear.