Light-Scattering Patterns from Collagen Films in Relation to the Texture of a Random Assembly of Anisotropic Rods in Three Dimensions

Abstract

Polarized light scattering from several types of collagen films cast from an acid soluble collagen and solubilized collagens by proteolitic enzyme (except callagenase) and from denatured films under various conditions, was observed under Hv and Vv polarization conditions.The scattering patterns from the collagen films were different from those from spherulitic films of polyalphaolefins. The patterns were analyzed in terms of a three-dimentional random assembly model of anisotropic rods resulting in the following conclusions. The polar angle of orientation of scattering elements with respect to the rod axis ranged from 50 to 70°, depending on the type of collagen film. The value of p, which is defined by (α⊥−αs)/(α||−α⊥), changes from very positive in the air-dried state to less positive, zero, or even slightly negative in the swollen state in saline, also depending on the types of collagen film.On the other hand, the characteristic Hv patterns were diminished in intensity with denaturation while the Vv patterns–as well as the wide angle X-ray diffraction pattern–were not changed to the same extent. This suggests that the light scattering from denatured films arises mainly from correlation in density fluctuations rather than that of orientation of local anisotropy; that is, it is suggested that denaturation causes disintegration of the crystalline superstructure rather than of the crystallites. These crystallites are too small in their correlation distance of the orientation fluctuation to give Hv scattering at such small scattering angles as several degrees only.