The effects of particleparticle interaction and viscosity of carrier fluid on steady and dynamic rheological responses and quasi-static penetration resistance of Twaron® fabrics treated with shear thickening and shear thinning suspensions have been investigated. The suspensions have been made by mechanically dispersing 60 nm silica (SiO2) and calcium carbonate (CaCO3) nanoparticles in poly ethylene glycol (PEG) with molecular weights of 200 and 400 g/mol. The CaCO3 suspensions display shear thinning behaviour along with the total dominance of the elastic state over the viscous state while the SiO2 suspensions exhibit shear thickening behaviour with the emergence of both the elastic and viscous states. With the increase of molecular weight of PEG, viscosity, viscoelastic modules and instability of the suspensions increase and critical shear rate and frequency of transition to elastic state diminish. The PEG200 and PEG400-contained SiO2 suspensions-treated Twaron® composites at 35 wt.% have quasi-static penetration resistances which are nearly 2.63 and 2.48 times and maximum absorbed energies which are about 1.54 and 1.55 times higher, respectively, than those of the corresponding CaCO3 ones. However, the influence of increasing the PEG’s molecular weight is not as considerable as the effect of particleparticle interaction on the enhancement of penetration resistance performance.
