PVP immobilized SiO 2 nanospheres for high-performance shear thickening fluid

Abstract

We develop a modified method to improve the rheological performance of SiO₂-based shear thickening fluid (STF). Directly adding surfactant into STF is the most common method to improve the rheological performance of SiO₂-based STF. However, the final viscosity increases quickly with the increase of shear rate, which is against for the practical applications. In this work, SiO₂ nanospheres are firstly modified by PVP K30 through an ethanol refluxing method and the modified SiO₂ nanospheres are used to prepare PVP@SiO₂-STF. Compared with the unmodified SiO₂ based STF (SiO₂-STF), the PVP@SiO₂-STF presents an obvious increase of shear thickening (ST) effects and the maximum viscosity increases by 7 times and the critical shear rates decrease about 10 times approximately. A reasonable explanation is proposed to interpret the influence of the modification methods on the rheological properties of STF. This work provides a new way to control the shear thickening behavior and also contributes to understand the mechanism of ST effect, which has an important significance to develop controllable STF.

Graphical abstract

Figure PVP immobilized SiO₂ based shear thickening fluid shows a dramatic improvement in shear thickening behavior (a, b, and c) and the illustration of the enhanced mechanism of shear thickening (d).

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