Fluids adsorbing in nanoporous solids cause high solvation pressures that deform the solids and affect properties of the fluids themselves. We calculate solvation pressure of nitrogen adsorbed at 77.4 K in spherical silica mesopores using two methods: the macroscopic Derjaguin–Broekhoff–de Boer theory and molecular simulations. We show that both approaches give consistent results, and the observed pressures increase in smaller pores reaching the order of a hundred megapascals. The results are also typical for the solvation pressure in mesoporous materials, yet noticeably differ from the results for the cylindrical pore geometry. Furthermore, we show that the dependence of the solvation pressure at saturation on the reciprocal pore size is linear, and we use this relation for the calculation of the solid–liquid surface energy. The results can be employed for the prediction of the solvation pressure and the adsorption‐induced deformation in the material with the spherical pore geometry.

中文翻译：

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球形中孔的溶剂化压力：宏观理论和分子模拟

吸附在纳米多孔固体中的流体会导致较高的溶剂化压力，从而使固体变形并影响流体本身的性能。我们使用两种方法来计算球形二氧化硅介孔中77.4 K处吸附的氮的溶剂化压力：宏观Derjaguin–Broekhoff–de Boer理论和分子模拟。我们表明，这两种方法都给出一致的结果，并且观察到的压力在较小的孔中增加，达到一百兆帕斯卡的量级。该结果对于中孔材料中的溶剂化压力也很典型，但与圆柱孔几何形状的结果明显不同。此外，我们表明饱和时溶剂化压力对反向孔径的依赖性是线性的，并且我们使用此关系来计算固液表面能。