Rheological behavior of collagen/chitosan blended solutions

Understanding the rheological behavior of collagen/chitosan blends is fundamental to design the optimized collagen/chitosan composite materials. Steady shear, dynamic frequency sweep, thixotropy and creep-recovery tests were investigated to characterize the rheological behavior of collagen/chitosan blends as a function of chitosan content (0%–90% [wt/wt]). All the samples showed pseudoplasticity with shear-thinning behavior. With the increase of chitosan, the viscosity significantly decreased from 862.54 to 0.60 Pa s at 0.05 s−1. The storage modulus and loss modulus also decreased while the dynamic denaturation temperature increased from 39.79 to 45.18°C. Besides, the thixotropy weakened and when the chitosan content reached 70%, the final recovery percentage was only 4.6%. The entanglements between collagen fibers observed by atomic force microscopy became weaker. Finally, the corresponding mathematical models were used to simulate the experimental data, and the obtained parameters might provide some useful theoretical guidance for the processing of the collagen/chitosan blended solutions. © 2021 Wiley Periodicals LLC.