Rheological response of shear thickening fluid reinforced with silicon nitride nanoparticles

In this study, we studied the shear thickening performance of a novel silicon nitride and silica-mixed nanoparticles suspension. Silicon-nitride/silica-shear thickening fluids (Si3N4/SiO2-STFs) with different mass fraction ratios were prepared using polyethylene glycol as a dispersion medium. For the Si3N4/SiO2-STFs, the results showed that the viscosity increased from 168.35 (0.0 wt% Si3N4) to 1387.73 Pa s (7.5 wt% Si3N4), and a concomitant decrease in the critical shear rate from 10.0 to 3.55 s-1, while thickening period decreased from 60.92 to 16.03 s-1. Dynamic rheological analysis showed that compared with SiO2-based STF (SiO2-STF), the peak values of storage and loss modulus of 7.5%Si3N4/20%SiO2-STF (7.5 wt% Si3N4 and 20 wt% SiO2) increased nearly six times and three times, respectively. The results also showed that, compared with SiO2-STF, the thickening ratio of 7.5%Si3N4/20%SiO2-STF increases by 174% at 45 degrees C and slows down the effect of temperature increase on the thickening period. This work provides a novel method for high-performance STF.