Anomalous diffusion in aqueous solutions of gelatin
Abstract
Dynamic-light-scattering experiments on semidilute aqueous solutions of gelatin indicate three relaxation processes: an exponential for times less than ~50 μsec followed by a power law at intermediate time and then a stretched exponential at long time. The characteristic time of the stretched exponential diverges as the system evolves to a gel. The latter two relaxations can be explained in terms of an anomalous diffusion mechanism where the mean-square displacement behaves as <R2>~lnt at intermediate time and <R2>~tβ with β<1 at late time. Length scales derivable from these diffusion mechanisms obey scaling, and it is proposed that β is related to the fracton density-of-states exponent and the fractal dimension of the gelatin molecules.
- Publication:
-
Physical Review A
- Pub Date:
- February 1992
- DOI:
- 10.1103/PhysRevA.45.2416
- Bibcode:
- 1992PhRvA..45.2416R
- Keywords:
-
- 82.70.Gg;
- 05.40.+j;
- 61.41.+e;
- Gels and sols;
- Polymers elastomers and plastics