Polymer and Materials Science
Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
A new model for hydrated collagen fibers is postulated. According to this model, a part of the water adsorbed is bound to the collagen fiber through hydrogen bonding, and the rest is randomly reorienting. The two types of water are in chemical exchange. The observed dipolar splitting for H2O and quadrupolar splitting for D2O are time-averaged values. The deuterium quadrupole splitting of D2O in oriented collagen fibers decreases in the presence of salt. The phenomenon can be explained either by a change in the structure of collagen or by the blocking of the water binding sites by the ions. In the EPR spectra of collagen presoaked in Mn(II) and Cu(II) sulfates, the line widths decrease with the increase of water content, indicating the coordination of the cations to water. The change in the hyperfine splitting (from 70 gauss in dry fibers to 96 gauss in fibers equilibrated at 100% RH) of Mn(II) with water content is explained by the change in the symmetry of its environment.
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