Solvent Isotherms and Structural Transitions in Nanoparticle Superlattice Assembly

Missoni, Leandro Luis; Upah, Alex; Zaldívar, Gervasio; Travesset, Alex; Tagliazucchi, Mario

doi:10.1021/acs.nanolett.4c00875

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Solvent Isotherms and Structural Transitions in Nanoparticle Superlattice Assembly

Missoni, Leandro Luis·Upah, Alex·Zaldívar, Gervasio·Travesset, Alex·Tagliazucchi, Mario

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Abstract

Here, we introduce a Molecular Theory for Compressible Fluids (MOLT-CF) that enables us to compute free energies and other thermodynamic functions for nanoparticle superlattices with any solvent content, including the dry limit. Quantitative agreement is observed between MOLT-CF and united-atom molecular dynamics simulations performed to assess the reliability and precision of the theory. Among other predictions, MOLT-CF shows that the amount of solvent within the superlattice decreases approximately linearly with its vapor pressure and that in the late stages of drying, solvent-filled voids form at lattice interstitials. Applied to single-component superlattices, MOLT-CF predicts fcc-to-bcc Bain transitions for decreasing vapor pressure and for increasing ligand length, both in agreement with experimental results. We explore the stability of other single-component phases and show that the C14 Frank-Kasper phase, which has been reported in experiments, is not a global free-energy minimum. Implications for precise assembly and prediction of multicomponent nanoparticle systems are discussed.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY Bain transformation Frank-Kasper phases free energy free-energy calculation lattices ligands molecular dynamics simulations molecular theory molecules solvent evaporation solvents

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Missoni, Leandro Luis, Upah, Alex, Zaldívar, Gervasio, Travesset, Alex, Tagliazucchi, Mario. 2024-04-22. Solvent Isotherms and Structural Transitions in Nanoparticle Superlattice Assembly. https://doi.org/10.1021/acs.nanolett.4c00875

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