Development and Performance Evaluation of Hybrid Iono-organogels for Efficient Impact Mitigation

Dissipative materials are essential for mitigating impact in various automotive, aerospace, and sports equipment applications. This study investigates the efficiency of a novel hybrid iono-organogel in dissipating and absorbing impact energies. The gel consists of a covalently cross-linked poly(acrylic acid)-<i>co</i>-poly(zwitterionic (DMAPS)) in a hybrid solvent system composed of the ionic liquid [C₂OHMIM][BF₄] and the oligomer PEG200. The optimal solvent hybridization ratio for achieving the lowest deceleration during impact testing is 40 vol % of the ionic liquid and 60 vol % of PEG200. The gel exhibits efficient mechanical dissipative properties with a loss factor exceeding 0.5 when solicited under various dynamic conditions with this optimized ratio. Moreover, the gel demonstrates high strength and toughness, enabling it to withstand impacts without experiencing catastrophic failure. The developed gel presents stable mechanical properties over broad temperature (0-100 °C) and frequency (0.01-2000 Hz) ranges. It maintains its performance during successive impacts, thanks to its self-recovery abilities. The remarkable mechanical properties of the gel are attributed to the abundance of combined functional groups within the gel polymeric network. Indeed, reversible H-bonds, ion-dipole, and dipole-dipole interactions were observed in different studies to enhance mechanical performance. Their unique synergy effect in the developed hybrid gels held promise for better control of impact properties and durability in numerous dynamic applications.