Preliminarily Revealing Rheological Behaviors of Mesoscale Collagen Fibrils in Suspension

Using natural mesoscopic collagen as the structural unit has gradually emerged as a promising processing strategy for the preparation of high-performance collagen materials. These mesoscopic collagen fibrils (CAs) are exfoliated from biological tissues and dispersed in liquid media to prepare subsequent materials. The present work explores the effects of solid content, size, and temperature on the rheological behavior of collagen fibril suspensions under shearing through steady-state and dynamic rheological studies. Suspensions tend to exhibit shear-thinning and gel-like behavior, attributed to mesoscopic collagen forming a rigid network. Suspensions with large-size collagen fibers (aspect ratio > 100) exhibit high resistance to shear deformation at low solid contents (0.5 wt%) due to the intensive physical entanglement. The viscosity of the suspension was temperature-dependent and decreased rapidly near the hydrated thermal denaturation temperature of collagen. This work reveals the interactions between mesoscale collagen's surface interfaces and provides the necessary theoretical basis for collagen processing.