HYDRODYNAMIC PROPERTIES OF GELATIN IN DILUTE-SOLUTIONS

Aggregation properties of Gelatin chains in neutral aqueous solutions, are reported in the temperature range T = 35-60 degrees C, from the m easured intrinsic viscosity [eta], diffusion coefficient, D-o, molecul ar weight M-W, and radius of gyration (R-g) data. Gelatin chains doubl ed their size as the solution was cooled to 35 degrees C from 60 degre es C. The intermolecular interaction was found to be repulsive which s howed significant decrease as the temperature was reduced. The data pr ovides excellent fitting to the scaling relations M-w[eta] = (1.96 +/- 0.06) x 10(-26)(R-e,R-eta/R-e,R-D)(3)(D-o eta(o)/T)(-3)and (D(o)n(1/2 ))(-1) similar or equal to(6(1/2)pi eta(o) gamma beta/k(B)/T)[1 + 0.20 1(v/beta(3))n(1/2)] where n is the number of segments in the chain. Th e ratio of the hydrodynamic radius (R-e,R-D) (deduced from D-o) and R- g,(R-e,R-D/R-g = xi) was found to be 0.555. From the known solvent vis cosity eta(o), the segment length beta, was deduced to be (15 +/- 2) A ngstrom. The deduced excluded Volume was v similar or equal to(4.1 Ang strom)(3). The Flory-Huggins interaction parameter (xi) did not show o bservable temperature dependence. (C) 1998 Elsevier Science B.V. All r ights reserved.