{ "id": "1805.03408", "version": "v1", "published": "2018-05-09T08:23:41.000Z", "updated": "2018-05-09T08:23:41.000Z", "title": "Continuous condensation in nanogrooves", "authors": [ "Alexandr Malijevský" ], "categories": [ "cond-mat.stat-mech" ], "abstract": "We consider condensation in a capillary groove of width $L$ and depth $D$, formed by walls that are completely wet (contact angle $\\theta=0$), which is in a contact with a gas reservoir of the chemical potential $\\mu$. On a mesoscopic level, the condensation process can be described in terms of the midpoint height $\\ell$ of a meniscus formed at the liquid-gas interface. For macroscopically deep grooves ($D\\to\\infty$), and in the presence of long-range (dispersion) forces, the condensation corresponds to a second order phase transition, such that $\\ell\\sim (\\mu_{cc}-\\mu)^{-1/4}$ as $\\mu\\to\\mu_{cc}^-$ where $\\mu_{cc}$ is the chemical potential pertinent to capillary condensation in a slit pore of width $L$. For finite values of $D$, the transition becomes rounded and the groove becomes filled with liquid at a chemical potential higher than $\\mu_{cc}$ with a difference of the order of $D^{-3}$. For sufficiently deep grooves, the meniscus growth initially follows the power-law $\\ell\\sim (\\mu_{cc}-\\mu)^{-1/4}$ but this behaviour eventually crosses over to $\\ell\\sim D-(\\mu-\\mu_{cc})^{-1/3}$ above $\\mu_{cc}$, with a gap between the two regimes shown to be $\\bar{\\delta}\\mu\\sim D^{-3}$. Right at $\\mu=\\mu_{cc}$, when the groove is only partially filled with liquid, the height of the meniscus scales as $\\ell^*\\sim (D^3L)^{1/4}$. Moreover, the chemical potential (or pressure) at which the groove is half-filled with liquid exhibits a non-monotonic dependence on $D$ with a maximum at $D\\approx 3L/2$ and coincides with $\\mu_{cc}$ when $L\\approx D$. Finally, we show that condensation in finite grooves can be mapped on the condensation in capillary slits formed by two asymmetric (competing) walls a distance $D$ apart with potential strengths depending on $L$.", "revisions": [ { "version": "v1", "updated": "2018-05-09T08:23:41.000Z" } ], "analyses": { "keywords": [ "chemical potential", "continuous condensation", "nanogrooves", "second order phase transition", "non-monotonic dependence" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }