Through hierarchical assembly at multi-scales, inhomogeneous supramolecular polymers (ISP) serve as a promising self-assembly foundry for creating high-performance materials that can perform multiple functions through combinations of structural properties and functional capability. Understanding the mechanisms governing hierarchical assembly of ISP plays a key role in unlocking such potential. From a computational perspective, the major challenge in simulating IPS is to efficiently resolve the interplay of chemical and thermodynamic equilibrium, as well as reaction kinetics and polymer dynamics. Previous methods either rely on a full particle-based approach that imposes prohibitive computational cost when applied to system with mesoscale structure features, or a full field-based approach that lacks a microscopic description of reversible supramolecular interactions. In this work, we develop a hybrid particle-field simulation approach that accounts for the weak van der Waals type interactions using <i>effective</i> fluctuating fields experienced by polymer segments, while retaining particle-based microscopic treatment for the strong supramolecular interactions. By doing so, the new hybrid paradigm wields the strengths of both worlds – with fully resolved specific supramolecular bonding and variable chemical kinetics, and computational efficiency in capturing mesoscale structure features. To validate the approach and to illustrate its applications, we examine three supramolecular systems: homogeneous simple associating fluids, end-functionalized homopolymers, and end-functionalized polymer blends in ordered micro-phases. By varying association strength, reaction kinetics and extent of immiscibility, we investigate the effects of coupled chemical-thermodynamic equilibrium, reaction-diffusion kinetics on equilibrium composition, micro-phase morphology, associative bonding/ rebonding lifetime, and polymer diffusion. Future applications of the method to more complicated IPS systems will also be discussed, with an aim of providing predictive knowledge for guiding experimental investigations.

Hybrid particle-field approach for simulating inhomogeneous supramolecular polymer networks

255th National Meeting (2018)

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