Rheological properties of konjac glucomannan composite colloids in strong shear flow affected by mesoscopic structures: Multi-scale simulation and experiment

Abstract

The rheological properties of biomacromolecule colloids under large shear rates (> 103 s-1) have attracted considerable interest due to the fundamental role in spraying of macromolecular solutions, degradation of macromolecular by atomization, and high-speed transportation of colloids. However, it is difficult for common instruments to characterize the rheological property under large shear rates and investigate the effect of the dynamical cluster structure on the rheological properties. In this study, multi-scale simulations and experiments were implemented to investigate the rheological property of biomacromolecule colloids composed of konjac glucomannan and hydroxypropyl methylcellulose. The multi-scale method combined with molecular dynamics simulation and Brownian dynamics simulation was effective and accurate to analyze the dynamical behavior of clusters (~ 500 nm) for a long time (~ 2 ms). Moreover, for the first time, the cluster structure and rheological properties in the strong shear flows were predicted by multi-scale simulations, such as the breakage of polymers and decreased storage modulus at large shear rates (104 ~ 105 s−1) where the test accuracy of common instruments is limited. This study provided more understanding of the rheological property of biomacromolecule colloids, which will shed light on the application of the biomacromolecule colloids in strong shear flows.