Monodisperse rat skin collagen solutions obtained through purification by density gradient separation have been studied by dynamic light scattering. Autocorrelation functions were measured at 31.8° and 90° scattering angles. Calculations of the translational diffusion coefficient DT and the rotational diffusion coefficient DR from the measured correlation functions of scattered light have been carried out in this study. A new approach to simulatanously determining the translational and rotational diffusion coefficients was used to estimate both the length of the macromolecules and the viscosity of the solutions. Our result for L is 2715±100 Å.

Gels formed from very polydispersive gelatin solutions were studied by intensity fluctuation spectroscopy. Single exponential autocorrelation functions were obtained for gelatin gels with and without a crosslinking agent. The elastic continuum model was found to adequately describe all the observed properties. As the concentration increases the cooperative diffusion coefficient Dc of the polymer network decreases in the solution state, but increases in the gel state. For gels without a crosslinking agent, the decay rate of the correlation function was found to remain constant after it reached a terminal value several hours after its temperature was lowered to 20 °C. However, for gels with a crosslinking agent, the decay rate continuously increased and the spatial correlation length became shorter with time.

Micelles formed from gelatin solutions were studied by sedimentation and optical mixing spectroscopy (OMS). We sampled gelatin solutions at various centrifugal speeds. Single exponential autocorrelation functions of the gelatin solutions were measured at 27°C and at 90° scattering angle by OMS. Calculation of the diffusion coefficient D from the measured autocorrelation function of scattered light has been carried out in this studied. A calculation of the micellar radius from the Stokes‐Einstein equation was carried out. We also calculated the sedimentation coefficient and molecular weight of gelatin micelles and found that the polydisperse gelatin micelles were formed at 50mg/mL.