Shear thickening fluids in cork composites for impact mitigation: the role of fumed silica concentration

Abstract

AbstractCork composites have shown excellent potential in impact mitigating systems. Their sustainability greatly surpasses the currently used solutions. In addition, recent advances in developing cork composites with shear thickening fluids (STFs) have demonstrated exciting results for impact mitigation. This study explores different STF formulations based on polyethylene glycol (PEG), with a molecular weight of 400 g/mol, and SiO2 particles, investigating their application in layered cork composites for impact mitigation. Different STF formulations are investigated by processing suspensions with different fumed silica concentrations ranging from 10 to 60 wt.%. Using a cone–plate configuration, rheological measurements were conducted on these suspensions, which were then employed as an interfacial layer in agglomerated cork composite layered structures. These hybrid composites were then subjected to 20 J impact tests. PEG 400 exhibited fluid final states for silica concentrations up to 30 wt.% and crystallised at higher concentrations. Based on the results, STF within cork layers was positive regarding impact force reduction, drawing insights for future application of STF suspensions in cork composites for impact mitigation. Graphical abstract