Enabling thermally enhanced vibration attenuation via biomimetic Zr–fumarate MOF-based shear thickening fluid

This work reported a biomimetic shear thickening fluid (STF) with thermally enhanced shear thickening effect for smart vibration attenuation system. It was developed by introducing Zr–fumarate metal-organic framework (MOF) crystals into a solvent mixture comprised of polyethylene glycol, polyacrylic acid and Ca2+, which endowed it with the cooperative effect of electrostatic and hydrophobic interactions. As the temperature raised from 25 to 35 °C, the STF containing 55 vol% MOF (STF-55) yielded a favorable shear thickening reinforcement with a notable viscosity growth of 1760-7953 Pa s. Besides, its storage modulus increased from 14 to 3036 Pa at 25–55 °C under a 0.1 Hz shear frequency, revealing a significant improvement in mechanical performance, as also demonstrated by transient shear rheological experiments. STF was incorporated into sandwich structures to improve the damping performance, with the natural frequency and damping ratio investigated at various ambient temperatures. Since the thermal enhanced viscosity could promote energy dissipation, the damping ratio of STF-55 filled sandwich structure obtained a substantial improvement from 0.85% to 1.93% at 25–55 °C. Thus, STF-55 based turbine blade and building damping pile were fabricated, which not only reduced the external vibration stimuli with average responsive accelerations of 7.3 and 0.8 m2s-1, but also presented attenuated levels of 6.9 and 0.6 m2s-1 at increasing temperatures, respectively. In conclusion, this work provided guiding approach for highly adaptive vibration attenuation at high-temperature environment.