Rheological properties of colloidal suspensions of alumina nanofibers

https://doi.org/10.1016/j.molliq.2022.120385

We have studied the rheological properties of colloidal suspensions based alumina nanofibers (ANF) with a mass fraction of 0.125–2 wt%. The ANFs used in this work are stand out by a high aspect ratio L/D ∼ 106–107 (dry ANF before dispersion) and ease of dispersion due to the self-organized aligned structure of ANF, which is characteristic of our synthesis method. It was shown that ANF suspensions are characterized by high colloidal stability, zeta potential has a significant dependence on ANF volume fraction. ANF have a strong effect on the shear viscosity of colloidal suspensions; non-Newtonian behavior is observed in suspensions with an ANF mass fraction of 0.5 wt%. A comprehensive study of the propagation of ultrasound in ANF suspensions was carried out. Based on experimental results on the scattering of ultrasound in suspensions and theoretical calculations, data on the bulk viscosity of ANF suspensions were obtained for the first time. The results of the study allow us to judge the possibility of using ANF as a promising fibrous additive to optimize the rheological properties of suspensions for various technical purposes, which include drilling muds, paint and varnish compositions, concrete-cement mixtures.