Dynamic mechanical analysis, coupled with polarized step-scan FTIR transmission spectroscopy, has been used to monitor the submolecular motional behavior of uniaxially oriented polyamide 11. The dynamic in-phase spectra depend upon the morphology of the samples as well as on the polarization directi
Optical characterization of orientation of collagen
โ Scribed by E. P. Chang; James C. W. Chien
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1973
- Tongue
- English
- Weight
- 353 KB
- Volume
- 12
- Category
- Article
- ISSN
- 0006-3525
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โฆ Synopsis
The optical properties of reconstituted collagen were characterized in the framework of a two-phase model. The total birefringence is assumed to be the sum of form birefringence AF, of amorphous birefringence As, and of crystalline birefringence Ac. The contribution of AF has been determined as a function of strain. The intrinsic values of A, and As were calculated to be 0.24 f 0.06 and 0.055 f 0.018, respectively. In the undeformed state, the observed birefringence is almost entirely due to the distortion of the electric field of the light at the phase boundary. Whereas there is a slight increase of form birefringence with increasing strain, the total birefringence shows much larger increments. The latter is attributable to orientation of the rodlike superstructures of the tropocollagen molecules.
๐ SIMILAR VOLUMES
Studies of the optical birefringence of solutions of acid-soluble collagen from rat-tail tendon a t 22ยฐC in the pH range 1.0-6.0 show that collagen exhibits an isotropic to mesophase transition only between pH 2.4 and 3.0 a t 10% weight concentration. Such liquid crystalline order is probably essent