A Network-Science-Integrated Feedback Loop for Design of Multifunctional Polymeric Rod-Like Nanocomposites

The technical objective of the proposed effort is to establish a theory-experiment feedback loop to accelerate discovery of novel polymer nanocomposites (PNCs) with optimized mechanical, thermal, and electrical properties. The proposed effort is motivated by theory that is rooted in a suite of novel multiscale processing and performance simulations, integrated with network science concepts and algorithms that have not previously been applied to materials science. The proposed effort will focus on high aspect ratio, rod-like, nanoparticles a theoretical platform that will seek to establish in silico realization of the experimental design, processing, and performance testing and identify key regions in a parameter space impossible to explore experimentally. The proposed experimental portions of the work will be used to reveal or confirm, then explore with theoretical guidance, the lucrative regions of parameter space, building from a novel and promising multifunctional PNC model system of single wall carbon nanotubes (SWCNTs) dispersed in a high-performance polyetherimide (PEI) matrix. More specifically, the proposed in silico simulation work begin with a well-understood PEI matrix system and single walled carbon nanotubes, and then seek to robustly simulate the processing conditions (i.e., time and temperature protocols imposed shear) to realize a wide range of simulated as-processed PNC films for a fixed set of parameters and populate a databased sufficient for ensemble-averaged statistics. The proposed simulation work will also seek to develop a suite of network science methods and algorithms to achieve PNC morphology characterization (to ultimately enable mapping of morphology features to properties), and to encode parametrized models for contact resistance and stress transfer at two key interfaces (interphase- nanoparticle and interphase-neat polymer) into functional property simulation algorithms to provide a key feedback loop with chemical design. The proposed, and integrated, experimental work will seek to characterize how SWCNT induced polymer crystallization affects other critical parameters, such as Tg, storage modulus, elastic modulus and stress-strain behavior broadly. An explicit model PNC system is proposed to co-develop the theoretical platform and its feedback loop with experiments, an also to enable in-situ monitoring of PEI crystal corona formation around the SWCNTs. Experimental characterization will incorporate Raman spectroscopy, centrifugation, photoluminescence (PL), AFM and TEM. The proposed effort will incorporate a robust suite of network analytics and computational methods to devise and explore a range of unprecedented designs and architectures to achieve the stated technical objective.