Interactions between similar and dissimilar charged interfaces in the presence of multivalent anions

Article Article scientifique Article Interactions between similar and dissimilar charged interfaces in the presence of multivalent anions eng 2018 author Moazzami Gudarzi Mohsen 788987 author Adam Pavel 813316 author Smith Alexander 855937 author Trefalt Gregor 786132 author Szilagyi Istvan 702956 author Maroni Plinio 644101 author Borkovec Michal 134121 9436-9448 10.1039/C8CP00679B 1463-9076 http://xlink.rsc.org/?DOI=C8CP00679B Direct force measurements involving amidine latex (AL) and sulfate latex (SL) particles in aqueous solutions containing multivalent ferrocyanide anions are presented. These measurements feature three different pairs of particles, namely SL–SL, AL–SL, and AL–AL. The force profiles are quantitatively interpreted in terms of the theory by Derjaguin, Landau, Verwey, and Overbeek (DLVO) that is combined with a short-ranged exponential attraction. In monovalent salt solutions, the AL particles are positively charged, while the SL particles are negatively charged. In solutions containing ferrocyanide, the charge of the AL particles is reversed as the concentration is increased. The longer-ranged component of all force profiles is fully compatible with DLVO theory, provided effects of charge regulation are included. At shorter distances, an additional exponential attraction must be introduced, whereby the respective decay length is about 2 nm for the AL–AL pair, and below 1 nm for the SL–SL pair. This non-DLVO force is intermediate for the asymmetric AL–SL pair. These additional forces are probably related to charge fluctuations, patch-charged interactions, or hydrophobic forces. Dewey 540 40 Département de chimie minérale, analytique et appliquée 145 false Physical Chemistry Chemical Physics 20 14 6a9711b3-ba67-4527-96c8-72aa8a7501fb Article (Published version) Restricted Interactions_MB_18.pdf 4629578 application/pdf restrictedAccess Faculté des sciences / Section de chimie et biochimie / Département de chimie minérale, analytique et appliquée

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Interactions between similar and dissimilar charged interfaces in the presence of multivalent anions	Physical Chemistry Chemical Physics			2018	308	1

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Adam, Pavel