Publications by authors named "Luis E Paniagua-Guerra"

Nanofluidics has made significant impacts and advancements in various fields, including ultrafiltration, water desalination, biomedical applications, and energy conversion. These advancements are driven by the distinct behavior of fluids at the nanoscale, where the solid-fluid interaction characteristic lengthscale is in the same order of magnitude as the flow conduits. A key challenge in nanofluidics is understanding hydrodynamic slip, a phenomenon in which fluids flow past solid boundaries with a non-zero surface velocity, deviating from the classical no-slip boundary condition.

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This paper reports on the effects of shear rate and interface modeling parameters on the hydrodynamic slip length (LS) for water-graphite interfaces calculated using non-equilibrium molecular dynamics. Five distinct non-bonded solid-liquid interaction parameters were considered to assess their impact on LS. The interfacial force field derivations included sophisticated electronic structure calculation-informed and empirically determined parameters.

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The present investigation assesses a variety of parameters available in the literature to model gold-water interfaces using molecular dynamics simulations. The study elucidates the challenges of characterizing the solid-liquid affinity of highly hydrophilic gold-water interfaces via wettability. As an alternative, the local pairwise interaction energy was used to describe the solid-liquid affinity of flat and curved surfaces, where for the latter, the calculation of a contact angle becomes virtually impossible.

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This paper reports on the effects of the chemical composition of graphene oxide (GO) sheets on the mechanical properties of bulk GO. Three key factors were analyzed: (i) the oxygenated functional groups' concentration, (ii) the content of intersheet water (moisture), and (iii) the presence of residual contaminants observed from the synthesis of GO. Molecular dynamics simulations using the reactive force field ReaxFF were conducted to model tensile strength, indentation, and shear stress tests.

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In this investigation, equilibrium molecular dynamics simulations were conducted to assess the influence of the interface modeling approach on the calculation of hydrodynamic slip in carbon nanochannels. A Green-Kubo formalism was implemented for the calculation of the slip length in water confined by graphite layers. The nonbonded interactions between solid and liquid atoms (interface models) were modeled using parameters optimized to represent the wetting behavior and adsorption energy curves from electronic structure calculations.

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