Effect of cellulose beads on shear-thickening behavior in concentrated polymer dispersions

In the present work, we investigated the role of cellulose beads as additive for tuning of shear thickening (ST) behavior of traditional colloidal silica-based shear thickening fluids (STFs). STFs were synthesized with colloidal silica in liquid polyethylene glycol (PEG-200). The ST behavior of cellulose-based STF was compared with silica-based STF in terms of the steady-state and dynamic rheological studies while keeping the same total mass loading in PEG-200 polymer matrix. The ST behavior of cellulose-based STF was found to be more than three times higher than the silica-based STF at the same concentration. It can be expected that the cellulose beads with dense surface hydroxyl groups are a prime reason for improved interfacial interaction between the liquid PEG chains and the PEG-coated silica nanoparticles through strong hydrogen bonding. Both the steady-state and dynamic rheological analyses confirmed the better shear thickening and strain thickening behavior, respectively, as well as higher energy absorption property for cellulose-based STFs. The improved ST behavior of porous cellulose-based STF is definitely due to the cluster formation. This has been justifiably complemented by SEM and in situ rheological microscopy analyses.