High Performance Zeolitic Imidazolate Framework-8 (ZIF-8) Based Suspension: Improving the Shear Thickening Effect by Controlling the Morphological Particle-Particle Interaction

A novel shear thickening fluid (Z-STF) was developed via dispersing zeolitic imidazolate framework-8 (ZIF-8) nanoparticles into ethylene glycol (EG). By varying the morphologies of the ZIF-8 nanoparticles, the rheological properties of the Z-STF were controlled. In comparison to the traditional SiO2 based STF (S-STF), the Z-STF showed a superior shear thickening behavior because of the porous nature and polyhedron morphology of the ZIF-8 nanoparticles. Firstly, the EG molecule could be incorporated into the micropores of ZIF-8, which increased the volume fraction of the dispersing phases and enhanced the hydrodynamic forces between the particles. Secondly, the poor relative sliding of truncated cubic particles led to easily form a more robust structure of frictional contact network in truncated cube ZIF-8 based STF (TCZ-STF) than in truncated rhombic dodecahedron ZIF-8 based STF (TRDZ-STF) and S-STF, thus the TCZ-STF showed smaller critical shear rates and higher maximum viscosities. This work provides a morphology turning method to design high performance STF and supplies a good understanding of the relationship between ST behavior and particles' structure. In view of the easy preparation and wonderful mechanical properties, the Z-STF possessed broad application in damping, body armor, and safe energy. (C) 2019 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.