Yielding and thixotropic cellulose microgel-based network in high-content surfactant for stably suspending of functional beads

Abstract

Functional particles, such as microcapsules of perfumes, enzymes, or anti-mite agents, are desired to stably suspend in the high-content surfactant solution, providing additional functionalities for household products. Due to the disassociation of high-content surfactant, most linear or branched polymers would fail to modify the rheological properties of the high-content surfactant solution, especially for the suspending ability. In this research, the 2,2,6,6-tetramethylpiperidine-1-oxyl oxidized bacterial cellulose microgel (T-microgel) and hydroxypropyl methylcellulose (HPMC) were employed as "island" and "chain," respectively, which could self-assemble together to fabricate a yield and thixotropic continuous network in a high-content surfactant solution. The suspending ability of microgel in high-content surfactant is better than cellulose nanofiber and carboxymethylcellulose. This is the first time to report a cellulose microgel-based rheological modifier. T-microgel/HPMC synthetic system mixed with high content surfactant presented a typical Carreau-Yasuka fluid. Meanwhile, the effects of the HPMC and surfactant on the rheological properties of the combined system were investigated, and an optimal ratio for the 'island'/'chain' synthetic system was found to modify its yield and thixotropy behavior successfully. The potential application of this combined system was explored and found to work with all kinds of surfactants at high concentrations, which is more advantageous than most commercial suspending agents.

Keywords: Cellulose microgel; High-content surfactant; Rheology-modifier.