Adsorption from Binary Solutions on the Polymer-Tethered Surfaces

• Published in: The journal of physical chemistry. B Vol. 116; no. 10; pp. 3115 - 3124
• Main Authors: Borówko, M, Sokołowski, S, Staszewski, T
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 15.03.2012
• Subjects: Adsorption; Computational fluid dynamics; Density; Fluid flow; Fluids; Mathematical models; Models, Theoretical; Polymers - chemistry; Segments; Solutions - chemistry; Surface chemistry; Surface Properties
• ISSN: 1520-6106; 1520-5207
• DOI: 10.1021/jp300114y

A density functional study of adsorption from binary solutions on surfaces modified with tethered chains is presented. The tethered chains are modeled as freely jointed tangent spheres. The fluid molecules are spherical. All species interact via the Lennard-Jones (12–6) potential. The substrate is neutral with respect to all chain segments but the surface-binding segment, and it interacts with the fluid molecules via a Lennard-Jones (9–3) potential. Depending on the parameters of the model, different shapes of the relative excess adsorption isotherms are found. The density profiles of all components are analyzed. It is shown that the surface region is highly inhomogeneous. An influence of the grafting density, the length of grafted chains, the nature of the solution, and its composition on the adsorption mechanism and the structure of the bonded-phase is investigated. The theoretical predictions are consistent with the results of computer simulations and experimental data.