PROTON NMR RELAXATION OF ADSORBED WATER IN GELATIN AND COLLAGEN

The dependence of the water self-diffusion coefficients as well as of the proton spin-lattice and spin-spin relaxation rates on the concentr ation have been studied in the gelatin-water system and in hydrated na tive collagen. The bound and free water fractions and the correspondin g spin-spin and spin-lattice relaxation rates have been determined wit hin the multi-phase water proton exchange model. Various theoretical m odels for the water proton cross-relaxation to the biopolymer have bee n studied and the results compared with the observed Larmor frequency dependence of the water proton spin-lattice relaxation rate.