Unraveling the relevance of graphene-fluid hydrodynamic coupling on the exfoliation of graphitein water

Liquid-phase exfoliation via shear flow is a widely adopted technique for the large-scale production of graphene. However, the underlying nano- and microscale exfoliation mechanisms remain poorly understood. In this work, we address this issue by performing hybrid nonequilibrium hydrodynamic simulat...

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Detalles Bibliográficos
Autores: Qi, Kai, Fonte, Claudio P., Stratford, Kevin, Zhang, Yuqing, Jiang, Xiujun, Pagonabarraga Mora, Ignacio
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2025
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/228170
Acceso en línea:https://hdl.handle.net/2445/228170
Access Level:acceso embargado
Palabra clave:Carboni
Grafè
Grafit
Hidrodinàmica
Carbon
Graphene
Graphite
Hydrodynamics
Descripción
Sumario:Liquid-phase exfoliation via shear flow is a widely adopted technique for the large-scale production of graphene. However, the underlying nano- and microscale exfoliation mechanisms remain poorly understood. In this work, we address this issue by performing hybrid nonequilibrium hydrodynamic simulations of coarse-grained defect-free graphite nanoplatelets immersed in a mesoscopic water fluid via the lattice Boltzmann method. This approach enables us to investigate graphene exfoliation up to 100 nm in length. Nonequilibrium effects, such as tumbling, alignment, and bending, are demonstrated. In particular, we reveal that due to the graphene-fluid hydrodynamic coupling, the graphite dynamics distorts the surrounding shear flow and reduces the local shear stress, thereby leading to an increase in the critical shear rate by a factor of 2 ∼ 4. This statement is fully supported by a theoretical analysis using a force-based criterion, i.e., overcoming the maximum interlayer van der Waals attraction, and hierarchical simulations: athermal and no coupling; athermal and hydrodynamic coupling; and thermal and hydrodynamic coupling. Our work unravels the paramount relevance of hydrodynamic coupling on graphene exfoliation and paves the way toward achieving large-scale nonequilibrium graphene simulations reminiscent of experiments.