Speaker
Description
Understanding transport phenomena in confined fluids remains a central challenge in liquid-state theory. When liquids are restricted to nanometric dimensions—such as in porous materials, mineral interfaces, and synthetic or biological nanopores—the large surface-to-volume ratio amplifies interfacial interactions and molecular-scale inhomogeneities. As a result, transport becomes highly sensitive to local structure, dynamics, and external gradients, enabling controlled coupling between fluid flow, solute transport, heat transfer, and charge dynamics. These effects underpin a wide range of applications, including energy conversion and storage, water purification, and nanopore-based sensing.
While continuum descriptions of coupled transport are well established at mesoscopic and macroscopic scales, nanoscale confinement introduces dominant contributions from thermal fluctuations, adsorption, electrical double layers, and molecular friction that are not adequately captured by standard constitutive relations. Addressing this regime therefore requires a framework that explicitly accounts for spatial non-locality and temporal memory effects at the molecular level. Here, we introduce a unified approach based on a space- and time-dependent response matrix to characterize transport in confined fluids.
Our framework formulates a generalized linear response relation linking local fluxes of mass, solute, heat, and charge to their conjugate driving fields—pressure, chemical potential, temperature, and electric potential. The resulting coupled response kernel captures non-local and transient correlations arising from confinement. We extract this kernel from equilibrium molecular dynamics simulations using an extended Green–Kubo formalism, thereby establishing a direct connection between microscopic fluctuations and collective transport behavior. This methodology allows us to resolve fundamental processes such as molecular layering, coupled advection–diffusion of solutes and heat, and charge relaxation, and to examine how coupled transport emerges across spatial and temporal scales.
Beyond providing spatially resolved transport coefficients, the present framework offers a transparent bridge to extended continuum descriptions, including dynamical density functional theory and mode-coupling theory. By linking atomistic dynamics to macroscopic transport formulations, our results advance the understanding of solid–fluid interfaces in nanoporous materials and provide a robust basis for modeling coupled transport processes at the nanoscale, with implications for energy, environmental, and subsurface systems.
| Country | United States of America |
|---|---|
| Acceptance of the Terms & Conditions | Click here to agree |
