Thermal fields give rise to thermal coupling phenomena, such as mass and charge fluxes, which are useful in energy recovery applications and nanofluidic devices for pumping, mixing or desalination. Here we use state of the art non-equilibrium molecular simulations to quantify the thermodiffusion of alkali halide solutions, LiCl and NaCl, confined in silica nanopores, targeting diameters of the order of those found in mesoporous silica nanostructures. We show that nanoconfinement modifies the thermodiffusion behaviour of the solution. Under confinement conditions, the solutions become more thermophilic, with a preference to accumulate at hot sources, or thermoneutral, with the thermodiffusion being inhibited. Our work highlights the importance of nanoconfinement in thermodiffusion and outlines strategies to tune mass transport at the nanoscale, using thermal fields.

中文翻译：

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抑制碱金属卤化物溶液在二氧化硅纳米孔中的热扩散

热场引起热耦合现象，例如质量和电荷通量，这在能量回收应用和用于泵送，混合或脱盐的纳米流体装置中很有用。在这里，我们使用最先进的非平衡分子模拟方法来量化限制在二氧化硅纳米孔中的碱金属卤化物溶液LiCl和NaCl的热扩散，其目标直径约为在介孔二氧化硅纳米结构中发现的直径。我们表明，纳米约束改变了溶液的热扩散行为。在限制条件下，溶液变得更嗜热，优选在热源或热中性条件下积聚，抑制了热扩散。我们的工作强调了纳米限制在热扩散中的重要性，并概述了在纳米级调整质量传输的策略，