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DOE OSTI · 2373217

Fluorophilic Sigma(σ)‐Lock Self‐Healable Copolymers

Gaikwad, Samruddhi·Urban, Marek W.
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Abstract

Although F-Containing molecules and macromolecules are often used in molecular biology to increase the binding with Lewis acidic groups by introducing favorable C−F dipoles, there is virtually no experimental evidence and limited understanding of the nature of these interactions, especially their role in synthetic polymeric materials. These studies elucidate the molecular origin of inter- and intra-Chain interactions responsible for self-healing of F-Containing copolymers composed of pentafluorostyrene and n-butyl acrylate units (p(PFS/nBA). Guided by dynamic surface oscillating force (SOF) and spectroscopic measurements supported by molecular dynamics (MD) simulations, these studies show that the reformation of σ-σ orbitals in −C−F of PFS and CH 3 CH 2 − of nBA units enables the recovery of entropic energy via fluorophilic-σ-lock van der Waals forces when PFS/nBA molar ratios are ~50/50. The strength of these interactions determined experimentally for self-healable PFS/nBA compositions is in the order ~0.3 kcal/mol which primarily comes from fluorophilic-σ-lock (~70 %) contributions. These interactions are significantly diminished for non-self-healable counterparts. Strongly polarized −C−F σ orbitals create lateral dipolar forces enhancing the affinity towards −C−H orbitals, facilitating energetically favorable interactions. Entropic recovery driven by non-Covalent bonding offers a valuable tool in designing materials with unique functionalities, particularly self-healable batteries and energy storage devices.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRYChemistryFluorine-Containing copolymersFluorophilic-σ-lock interactionsSelf-healing

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Gaikwad, Samruddhi, Urban, Marek W.. 2024-05-13. Fluorophilic Sigma(σ)‐Lock Self‐Healable Copolymers. https://doi.org/10.1002/anie.202405504

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY subjectCHEMISTRY subjectFluorine-Containing copolymers subjectFluorophilic-σ-lock interactions subjectSelf-healing subject

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