Bioinspired Glass Composites with Damage-Sensing Functionalities

Lightweight composites have become key structural materials for aircrafts and future energy-efficient transportation systems. Nevertheless, the design of composites featuring high strength and high fracture toughness remains an open challenge due to the usual trade-off between these sets of properties in most manmade materials. Taking inspiration from the strong and tough hierarchical architecture of mollusk shells, I designed and fabricated fracture-resistant glass-reinforced composites by combining soft polymer layers with alternating, nacre-like layers that are infiltrated with the same polymer.¹ In my talk, I will highlight the fracture behavior and the toughening mechanisms that govern the high crack growth resistance of these hierarchical glass composites. In particular, I will focus on the effects of plastic deformation and bridging by the polymer phase on the early- and late stages of the fracture process. These effects have been elucidated by using a mechanochromic organic phase, capable of pre-emptively detecting and reporting the evolution of damage through a simple optical readout. The composites signal the presence of damage via a fluorescence color change that arises from the force-activation of mechanophore molecules embedded in the organic matrix.² By optical imaging mechanically loaded composites it is possible to localize damage prior to fracture and to elucidate the key role of plasticity during rupture of the hierarchical composites. Although several examples have shown that polymers can be made damage-reporting using mechanophores, just a handful of examples have targeted the reinforcing phase for the same purpose. To fill this gap, I will also highlight progresses on how high-aspect-ratio glass-reinforcing particles, directly gathered from the upcycling of glass industry residuals, can be engineered to provide optical warnings before and during extended fracture events. With this research, I aim at displaying how multifunctional bioinspired glass composites, capable of combining high strength, high toughness and damage-sensing properties can be fabricated and characterized. I will provide new insights into the interplay of multiscale toughening mechanisms in hierarchical bioinspired architectures and I will offer guidelines for the design of novel multifunctional bioinspired composites.<br/><br/>References<br/>T Magrini, A Senol, R Style, F Bouville, AR Studart, <i>Journal of the Mechanics and Physics of Solids</i> (<b>2022</b>) 159, 104750<br/>T Magrini, D Kiebala, D Grimm, A Nelson, S Schrettl, F Bouville, C Weder, AR Studart, <i>ACS Applied Materials & Interfaces </i>(<b>2021</b>) 13 (23), 27481-27490