Multiscale exploration - from quantum chemistry to macro - of advanced filler-matrix interfaces in composites
Abstract
Interfaces between the constituents are the key to composites strength, thermal and corrosion resistance. With prior AFOSR support we have developed concepts and models of inter-tubular traction in the aligned carbon nanotubes (CNT) assemblies, demonstrated that observable strength scales with interface friction and the CNT-elements length (ACS Nano, 15, 1342, 2021), discovered how the domain morphology reduces the strength (npj Comp. Mater. 8, 15, 2022). Most importantly, we revealed the fatigue origin not from CNT-lattice but from the interfaces (Science Adv. 7, eabj6996, 2021). Building on these insights, we expand predictive models to quantum-chemistry interface dynamics for materials of interest to the Air Force, due to anticipated extraordinary performance- CNT and boron nitrogen BNNT as super-strong 1D-fillers in composites or as fibers, MXenes as example of 2D-filler. For all, the covalent bonds between the filler-units (CNT-CNT, BNNT-BNNT, etc.) or links to matrix are crucial. We will explore, at the molecular level, the bonds ability to recover repeatedly, as in preliminary data for greater thanC=Cless than and greater thanBNless than links. Through ab initio molecular dynamics, we aim to determine the best recoverable crosslinks, to serve for highest toughness of fibers-composites where matrix is reduced to molecular interface. By analogy with vitrimers, we will investigate their interfaces, bonding to fillers. We also turn to rather different interfaces definitive in ultra-high temperature ceramics (UHTC), of importance to the Air Force and Space Force. The melting, segregation, oxidation all begin at the interfaces- surfaces, grain boundaries, in materials like ZrB2, SiC, WC. Models at most accurate ab initio level, key defects, and local interface melting definitive for the limits of resistance at extreme conditions of hypersonics, will be computed.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 06, 2025
- Source ID
- FA95502410162
Entities
People
- Boris I Yakobson
Organizations
- Air Force Office of Scientific Research
- Rice University
- United States Air Force