A Network-Science-Integrated Feedback Loop for Design of Multifunctional Polymeric Rod-Like Nanocomposites
Abstract
Major Goals: Discoveries and realizations over the last 20 months have disrupted the conventional wisdom that higher loading of SWCNTs achieves better performance properties. This has been proven demonstrably false in the new class of SWCNT-polyetherimide (PEI) nanocomposites developed by the Dingemans lab. Figure 1a below reveals a striking, non-monotone, strain at failure relationship, with a strong peak of 12-24% strain at 0.1% volume loading of SWCNTs in the ODPA-P3 neat polymer. This extremely promising peak performance behavior is followed by a sharp decline, already below the neat polymer 4% strain failure by 0.6% loading, that degrades even more for all higher loadings. Furthermore, Figure 1b reveals the average toughness (~10 J/g) has a similar peak at 0.1% loading, and Figure 1c reveals the average yield strength (~90 MPa) rises to a maximum plateau at 0.1% with no gains at higher loading. Figure 1d reveals that only the elastic modulus rises monotonically with vol% loading, from the already high performance 2.5 GPa of the neat polymer, to 2.6-3.0 GPa at 0.1%, and then 3.0-4.5 GPa with high variability until 4.4% and higher loadings. These results point to a completely new performance class of SWCNT-PNCs, anchored in the novel conformational flexibility of PEI polymers at SWCNT interfaces to template a crystalline interphase. This new performance class has a unique combination of performance properties: preservation and gains in the high-performance thermoelectric [1] and mechanical property ranges of the ODPA-P3 neat polymer shown in Figure 1, and, unprecedented temperature-usage ranges (above 200 deg C for the neat polymer, and higher with SWCNT loadings [2-4]). Our research effort involves tight collaboration and feedback between experimental, theoretical, and computational expertise, combining the experiences and perspectives of this diverse set of PIs and their trainees.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 18, 2020
- Accession Number
- AD1113923
Entities
People
- Mark G. Forest
Organizations
- University of North Carolina at Chapel Hill