Studies of Dynamic Material Interfaces in Extreme Environments - Renewal
Abstract
This program will examine critical aspects of the chemical and physical behavior of dynamic material interfaces operating in extreme environments. The proposed studies are relevant to both Air Force atmospheric terrestrial flight and orbital spaceflight systems. These studies will employ a unique combination of molecular beams coupled with atomic-resolution microscopy, and will be supported by accurate theory and numerical simulations. The studies will provide precise information on energy and momentum transfer, heterogeneous reaction mechanisms, and materials evolution in aggressive chemical environments. Importantly, proposed energy transfer experiments represent a new approach for quantifying adiabatic versus non-adiabatic interfacial energy dissipation. Moreover, experiments probing on-surface chemical dynamics will provide a new and information-rich complement to more traditional scattering or microscopy only experiments. Such on-surface experiments will reveal how time-evolving surface characteristics influence interfacial reactivity, materials integrity, and energy transfer for energetic collisional processes at interfaces. Time-lapse visualization of reacting interfaces will further allow us to probe the reactivity of specific sites at interfaces and how the presence of a reacted site or local region influences the subsequent reaction probability at proximal sites. Such correlations are important in understanding catalysis as well as materials oxidation and erosion. Gas-surface collisions will be investigated involving high temperature, high velocity gas flows, severe oxidative conditions, optical and charged particle illumination, and gaseous condensation at low temperatures under non-equilibrium flow conditions including isotopically-selective processes. Interfaces featuring dynamic and switchable structure will open a new direction for controllable energy-momentum exchange. This effort will also examine the formation of adsorbed molecular ices in support of Air Force materials development and flight operations in cold environments. In sum, the knowledge obtained from this program will provide the microscopic basis for understanding interfacial aerodynamic performance, chemical reactivity and materials stability, helping to guide the development of next-gen flight and propulsion systems.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 06, 2025
- Source ID
- FA95502410338
Entities
People
- Steven J. Sibener
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Chicago