Extreme Dynamic Performance of Nanofiber Mats under Supersonic Impacts Mediated by Interfacial Hydrogen Bonds

Achieving extreme dynamic performance in nanofibrous materials requires synergistic exploitation of intrinsic nanofiber properties and inter-fiber interactions. Regardless of the superior intrinsic stiffness and strength of carbon nanotubes (CNTs), the weak nature of van der Waals interactions limits the CNT mats from achieving greater performance. We present an efficient approach to augment the inter-fiber interactions by introducing aramid nanofiber (ANF) links between CNTs, which forms stronger and reconfigurable interfacial hydrogen bonds and pi-pi stacking interactions, leading to synergistic performance improvement with failure retardation. Under supersonic impacts, strengthened interactions in CNT mats enhance their specific energy absorption up to 3.6 MJ/kg, which outperforms widely used bulk Kevlar-fiber-based protective materials. The distinct response time scales of hydrogen bond breaking and reformation at ultrahigh-strain-rate (similar to 10(7)-10(8) s(-1)) deformations additionally manifest a strain-rate-dependent dynamic performance enhancement. Our findings show the potential of nanofiber mats augmented with interfacial dynamic bonds-such as the hydrogen bonds-as low-density structural materials with superior specific properties and high-temperature stability for extreme engineering applications.

Automated summary

By introducing aramid nanofibers to enhance inter-fiber interactions in carbon nanotubes, the researchers were able to improve the performance of nanofibrous materials, particularly in terms of specific energy absorption during supersonic impacts. The breaking and reformation of hydrogen bonds at ultrahigh-strain rates showed a strain-rate-dependent dynamic performance enhancement.