Multifunctional polymer nanocomposites with Mechanically-activated fluorescence
Abstract
Polymer nanocomposites are multifunctional materials that meet the needs for many applications, including structural resins, armor, lightweight reinforcing materials, and more. These materials are generally characterized by their great strength, thermal stability, chemical compatibility, and facile processing and curing conditions. However, two problems continue to persist: 1) insufficient dispersive forces lead to nanoparticle aggregation, and 2) the failure mechanism of high performance composites is still not well documented. The dispersion of nanoparticle additives has received significant attention, with the most successful strategy being to tune the matrix chemistry and/or nanoparticle surface functionality to improve the nanoparticle solubility in the matrix. To better probe the mechanical response and failure of nanocomposites, mechanoresponsive groups have been incorporated into the polymer matrix that, for example, produce light when mechanically activated. This approach enables spatial and temporal observation of molecular changes to the thermoset under a mechanical stress or strain, but typically introduces complex synthetic steps and covalent linkages weaker than the matrix. The research goals of the proposed work are to investigate thermoset nanocomposites that deliver synthetic versatility, robust thermomechanical properties, and failure diagnostics using a new design strategy. In particular, the nanoparticle-matrix interactions will be tuned by varying the matrix chemistry in parallel with varying the surface functionalization of quantum dots (QDs) and CNTs. The CNTs will be modified with a fluorescent dye that forms a Fšrster-resonance energy transfer (FRET) pair with the QD, which we have demonstrated enables strain-activated fluorescence in these nanocomposites. This project will explore how the matrix chemistry can be used to tune the sensitivity of the strain responsiveness as well as how frequency and temperature impact the time-dependent response and fluorescence intensity. The outcomes of this project will include a new non-destructive mechanical failure diagnostic tool as well as a more fundamental correlation bewteen matrix-nanoparticles interactions and nanoparticle dispersion in polymeric nanocomposites.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 20, 2022
- Source ID
- W911NF2210243
Entities
People
- Matthew D. Green
Organizations
- Arizona State University
- Army Contracting Command
- United States Army