Interfacial Water Is Separated from a Hydrophobic Silica Surface by a Gap of 1.2 nm

The interaction of liquid water with hydrophobic surfaces is ubiquitous in life and technology. Yet, the molecular structure of interfacial liquid water on these surfaces is not known. By using a 3D atomic force microscope, we characterize with angstrom resolution the structure of interfacial liquid...

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Detalles Bibliográficos
Autores: Arvelo, Diana M, Comer, Jeffrey, Schmit, Jeremy, García García, Ricardo
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2024
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/383897
Acceso en línea:http://hdl.handle.net/10261/383897
https://api.elsevier.com/content/abstract/scopus_id/85198183535
Access Level:acceso abierto
Palabra clave:3D AFM
hydrophobic gap
hydrophobic surfaces
interfacial water
self-assembled monolayers
silica−water interfaces
Descripción
Sumario:The interaction of liquid water with hydrophobic surfaces is ubiquitous in life and technology. Yet, the molecular structure of interfacial liquid water on these surfaces is not known. By using a 3D atomic force microscope, we characterize with angstrom resolution the structure of interfacial liquid water on hydrophobic and hydrophilic silica surfaces. The combination of 3D AFM images and molecular dynamics simulations reveals that next to a hydrophobic silica surface, there is a 1.2 nm region characterized by a very low density of water. In contrast, the 3D AFM images obtained of a hydrophilic silica surface reveal the presence of hydration layers next to the surface. The gap observed on hydrophobic silica surfaces is filled with two-to-three layers of straight-chain alkanes. We developed a 2D Ising model that explains the formation of a continuous hydrocarbon layer on hydrophobic silica surfaces.