2021/01/01 by Jean Comtet, Comtet, Jean, Archith Rayabharam +15 · 1 citation
Biochemistry, Genetics and Molecular Biology · Chemistry · Physics and Astronomy · #Electrochemical Analysis and Applications #FOS: Physical sciences #Force Microscopy Techniques and Applications #Lipid Membrane Structure and Behavior #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Soft Condensed Matter (cond-mat.soft)
paper · pdf · doi:10.48550/arxiv.2101.00231
openalex publication_date 2021/01/01 · openalex created_date 2022/07/25 · openalex updated_date 2026/07/28
Understanding the dynamics of charge exchange between a solid surface and a\nliquid is fundamental to various situations, ranging from nanofiltration to\ncatalysis and electrochemistry. Charge transfer is ultimately determined by\nphysicochemical processes (surface group dissociation, ion adsorption, etc...)\noccurring in the few layers of molecules at the interface between the solid and\nthe liquid. Unfortunately, these processes remain largely uncharted due to the\nexperimental challenges in probing interfacial charge dynamics with\nsufficiently high spatial and temporal resolution. Here, we resolve at the\nsingle-charge scale, the dynamics of proton charges at the interface between an\nhBN crystal and binary mixtures of water and organic amphiphilic solvents (e.g.\nalcohol), evidencing a dramatic influence of solvation on interfacial dynamics.\nOur observations rely on the application of spectral Single Molecule\nLocalization Microscopy (sSMLM) to two types of optically active defects at the\nhBN surface, which act as intrinsic optical markers for both surface\nprotonation and interaction with apolar alkyl groups of the organic solvent. We\nuse sSMLM to reveal interfacial proton charge transport as a succession of\njumps between the titratable surface defects, mediated by the transport of the\nsolvated proton charge along the solid/liquid interface. By changing the\nrelative concentration of water in binary mixtures, we evidence a non-trivial\neffect on interfacial proton charge dynamics, leading at intermediate water\nconcentration to an increased affinity of the proton charge to the solid\nsurface, accompanied by an increased surface diffusivity. These measurements\nconfirm the strong role of solvation on interfacial proton charge transport and\nestablish the potential of single-molecule localization techniques to probe a\nwide range of dynamic processes at solid/liquid interfaces.\n