8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

P7.126Thu 811:10-14:00Simulation of one-layer adsorption from non-uniformbinary solutionPavlo Yakunov 1 and Dmytro Gavriushenko 11 Physics Department, Taras Shevchenko Kyiv National University, 6 Glushkova prosp. ,k. 1, UA-03022, Kyiv, UkraineOne-layer adsorption from binary solution was considered. This kind of adsorption can be observedexperimentally in the case of adsorption to the surface modified by spacers because eachspacer can attach only one molecule of adsorbate. The surface was modeled by square lattice thatpossess a spacer in each knot. This surface contacted with a binary solution that was a source ofadsorbate. We had supposed that only one component of this solution can be adsorbed. Two kindsof surfaces were studied: plane and cylinder. The curvature of the surface was shown to change thecollocation of spacers and to affect the process of adsorption in this way. This problem was solvedboth theoretically and by the means of computer simulation using the Monte-Carlo method. Thetemperature dependence of adsorption coefficient was found as a result. In the second part of thiswork the influence of the phase transition in the solution on the adsorption was studied. We havemodeled the binary solution by the system with cubic lattice that is limited in one direction. Thiscase can be realized in a flat pore in homogeneous gravitational field or in flat pore with wall potential.This model had been considered and an expression for temperature dependence of chemicalpotential near the critical point of demixing had been obtained. The temperature dependence ofadsorption coefficient near the critical point of demixing was found as a result. We showed that theadsorption coefficient is affected not only by the curvature of adsorbent, but also by the influenceof phase transition in the bulk.126