Hybrid Nanocrystals of Small Molecules and Chemically Disordered Polymers
journal contributionposted on 2022-05-19, 16:11 authored by Eric P. Bruckner, Tine Curk, Luka Đorđević, Ziwei Wang, Yang Yang, Ruomeng Qiu, Adam J. Dannenhoffer, Hiroaki Sai, Jacob Kupferberg, Liam C. Palmer, Erik Luijten, Samuel I. Stupp
Organic crystals formed by small molecules can be highly functional but are often brittle or insoluble structures with limited possibilities for use or processing from a liquid phase. A possible solution is the nanoscale integration of polymers into organic crystals without sacrificing long-range order and therefore function. This enables the organic crystals to benefit from the advantageous mechanical and chemical properties of the polymeric component. We report here on a strategy in which small molecules cocrystallize with side chains of chemically disordered polymers to create hybrid nanostructures containing a highly ordered lattice. Synchrotron X-ray scattering, absorption spectroscopy, and coarse-grained molecular dynamics simulations reveal that the polymer backbones form an “exo-crystalline” layer of disordered chains that wrap around the nanostructures, becoming a handle for interesting properties. The morphology of this “hybrid bonding polymer” nanostructure is dictated by the competition between the polymers’ entropy and the enthalpy of the lattice allowing for control over the aspect ratio of the nanocrystal by changing the degree of polymer integration. We observed that nanostructures with an exo-crystalline layer of polymer exhibit enhanced fracture strength, self-healing capacity, and dispersion in water, which benefits their use as light-harvesting assemblies in photocatalysis. Guided by computation, future work could further explore these hybrid nanostructures as components for functional materials.
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future work couldpolymer backbones formpolymers ’ entropysmall molecules cocrystallizehighly ordered latticecrystalline ” layerchemically disordered polymerssmall moleculescrystalline layerpolymer integrationlattice allowinghighly functionaldisordered chainswrap aroundtherefore functionsynchrotron xside chainsray scatteringrange orderpossible solutionpolymeric componentorganic crystalsoften brittlenanoscale integrationliquid phaselimited possibilitiesinteresting propertiesinsoluble structureshybrid nanocrystalshealing capacityharvesting assembliesfunctional materialschemical propertiesaspect ratioadvantageous mechanicalabsorption spectroscopy