Nanoconfined water phase transitions in infinite graphene slits: Molecular dynamics simulations and mean-field insights

Autor(es)

Hawthorne, Felipe ; Neta, Virgilia M. S. ; Freire, Jose A. ; Woellner, Cristiano F.

• Tipo de documento: Artigo Científico
• Fonte: CARBON TRENDS; v. 19, p. 10-pg., 2025-02-27.

Resumo

Recent experimental and computational studies have demonstrated that nanoconfinement profoundly alters phase behavior of water, facilitating complex phase transitions at pressures and temperatures far lower typically observed in bulk systems. When combined with adsorption, nanoconfinement substantially enhances water uptake, primarily due to condensation occurring at the onset of the isotherm curve-a phenomenon intimately related to the facilitated formation of hydrogen bond networks. In this study, we adopt approach to investigate water confined within infinite graphene slits. Our Molecular Dynamics simulations reveal hysteresis across all investigated temperatures. Unlike in finite slits, where hysteresis arises surface tension effects at the edges, in the case of infinite slits, the hysteresis is the result of a genuine transition at the nanoscale. We analyze the spatial and orientational arrangements of the water molecules, demonstrating how the graphene surface promotes the formation of a hydrogen bond network in the adjacent water layers. The remarkably low pressure required for water uptake in this nano-environment is explained the mean-field level using a simple interacting lattice model. This is attributed to the exponential dependence of the critical pressure on the adsorbate-adsorbent interaction. (AU)

• Processo FAPESP: 19/17874-0 - EMU concedido no Proc. 2013/08293-7, KAHUNA upgrade - HPE Apollo Gen10 Supercomputer
• Beneficiário: Munir Salomao Skaf
• Modalidade de apoio: Auxílio à Pesquisa - Programa Equipamentos Multiusuários
• Processo FAPESP: 13/08293-7 - CECC - Centro de Engenharia e Ciências Computacionais
• Beneficiário: Munir Salomao Skaf
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs