Influence of Fiber Aspect Ratio and CPAM on Bubble Dynamics and Rheology in Bagasse Suspensions

A critical gap remains in understanding how fiber rheological properties govern bubble dynamics within suspensions, which is a key factor in fiber-based foam formation and performance. This study systematically explores the effects of bagasse fibrillated fiber (BFF) aspect ratio, concentration, and cationic polyacrylamide (CPAM) addition on suspension rheology and bubble behavior. BFF was prepared using an ultrafine grinder, followed by centrifugal fractionation to obtain fibers with controlled aspect ratios. Experimental analyses combined with molecular dynamics (MD) simulations revealed correlations among fiber aspect ratio, concentration, and suspension rheology. The results show that (1) increasing BFF aspect ratio and concentration enhances suspension viscosity, yield stress, and fiber networking, suppressing lateral bubble motion and deformation; (2) BFF concentrations exceeding 0.2 wt % exhibit inconsistent stabilization due to multiscale fiber heterogeneity; and (3) CPAM above 0.5 g/L consistently improves bubble shape/size stability by strengthening fiber cross-linking via electrostatic interactions. These findings provide theoretical and practical insights into designing aqueous fiber foams with applications in sustainable packaging, sound insulation, and thermal management.