Specific Ion Effects in Cholesterol Monolayers Castillo Santaella, Teresa del Maldonado Valderrama, Julia Faraudo Gener, Jordi Martín-Molina, Alberto Ionic specificity Cholesterol Langmuir monolayers Molecular dynamics simulations Surface forces The interaction of ions with interfaces and, in particular, the high specificity of these interactions to the particular ions considered, are central questions in the field of surface forces. Here we study the effect of different salts (NaI, NaCl, CaCl2 and MgCl2) on monolayers made of cholesterol molecules, both experimentally (surface area vs. lateral pressure isotherms measured by a Langmuir Film Balance) and theoretically (molecular dynamics (MD) all-atomic simulations). We found that surface isotherms depend, both quantitatively and qualitatively, on the nature of the ions by altering the shape and features of the isotherm. In line with the experiments, MD simulations show clear evidences of specific ionic effects and also provide molecular level details on ion specific interactions with cholesterol. More importantly, MD simulations show that the interaction of a particular ion with the surface depends strongly on its counterion, a feature ignored so far in most theories of specific ionic effects in surface forces. 2017-02-22T12:01:27Z 2017-02-22T12:01:27Z 2016 info:eu-repo/semantics/article Castillo-Santaella, T. [et al]. A. Specific Ion Effects in Cholesterol Monolayers. Materials 2016, 9, 340. [http://hdl.handle.net/10481/45003] 1996-1944 http://hdl.handle.net/10481/45003 spa http://creativecommons.org/licenses/by-nc-nd/3.0/ info:eu-repo/semantics/openAccess Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License MDPI