2024 AIChE Annual Meeting
(274f) Multi-Scale Understanding of the Tunable Mechanical Behavior Metallo–Polyelectrolyte Complexes
Authors
Lee, S., California Institute of Technology
Velling, S., California Institute of Technology
Fiori, C., California Institute of Technology
Greer, J. R., California Institute of Technology
Wang, Z. G., California Institute of Technology
Metallo-polyelectrolyte complexes (MPEC) represent a unique class of materials where multi-valent metal ions embedded into soft organic frameworks undergo reversible electrostatic interactions through the formation and dissociation of dynamic crosslinks. These molecular-level processes give rise to a wide range of material dynamic responses, such as impressive mechanical stiffness and fracture toughness. However, developing a fundamental understanding of the link between molecular-level interactions and material properties presents a challenge, owing to the diverse length- and timescales inherent to the system. In light ofthis challenge, we employ a range of theoretical modeling methodologies to interrogate the variousscales intrinsic to MPEC dynamics. Leveraging quantum Density Functional Theory (DFT), we discern the correlation between the identity of metal ions and the binding energy of dynamic crosslinks. Building upon this insight, we formulate a mean-field theory mapping the phase-space of MPEC across various metal-ion valencies. This theoretical framework serves as a foundation for initializing coarse-grained molecular dynamics simulations, wherein an examination of ion-pair and polymer relaxation times provides an understanding of the mechanical behavior exhibited by MPEC. This multi-scale comprehension of MPEC not only facilitates a deeper theoretical insight but also informs experimental endeavors aimed at exploring the practical applications of MPEC, for example: stimuli-responsiveness, self-healing, dissolution in solvent, and improved toughness through enhanced energy dissipation.