surface forces; atomic force microscopy; polyelectrolytes; adsorption; multivalent ions
Smith Alexander M., Maroni Plinio, Borkovec Michal (2018), Attractive non-DLVO forces induced by adsorption of monovalent organic ions, in Physical Chemistry Chemical Physics
, 20(1), 158-164.
Moazzami-Gudarzi Mohsen, Adam Pavel, Smith Alexander M., Trefalt Gregor, Szilágyi István, Maroni Plinio, Borkovec Michal (2018), Interactions between similar and dissimilar charged interfaces in the presence of multivalent anions, in Physical Chemistry Chemical Physics
, 20(14), 9436-9448.
Trefalt Gregor, Szilagyi Istvan, Téllez Gabriel, Borkovec Michal (2017), Colloidal Stability in Asymmetric Electrolytes: Modifications of the Schulze–Hardy Rule, in Langmuir
, 33(7), 1695-1704.
Trefalt Gregor, Palberg Thomas, Borkovec Michal (2017), Forces between colloidal particles in aqueous solutions containing monovalent and multivalent ions, in Current Opinion in Colloid & Interface Science
, 27, 9-17.
Moazzami-Gudarzi Mohsen, Maroni Plinio, Borkovec Michal, Trefalt Gregor (2017), Depletion and double layer forces acting between charged particles in solutions of like-charged polyelectrolytes and monovalent salts, in Soft Matter
, 13(18), 3284-3295.
Cao Tianchi, Sugimoto Takuya, Szilagyi Istvan, Trefalt Gregor, Borkovec Michal (2017), Heteroaggregation of oppositely charged particles in the presence of multivalent ions, in Physical Chemistry Chemical Physics
, 19(23), 15160-15171.
Moazzami-Gudarzi Mohsen, Kremer Tomislav, Valmacco Valentina, Maroni Plinio, Borkovec Michal, Trefalt Gregor (2016), Interplay between Depletion and Double-Layer Forces Acting between Charged Particles in Solutions of Like-Charged Polyelectrolytes, in Physical Review Letters
, 117(8), 088001-088001.
Valmacco Valentina, Elzbieciak-Wodka Magdalena, Herman David, Trefalt Gregor, Maroni Plinio, Borkovec Michal (2016), Forces between silica particles in the presence of multivalent cations, in Journal of Colloid and Interface Science
, 472, 108-115.
Trefalt Gregor, Behrens Sven Holger, Borkovec Michal (2016), Charge Regulation in the Electrical Double Layer: Ion Adsorption and Surface Interactions, in Langmuir
, 32(2), 380-400.
Valmacco Valentina, Elzbieciak-Wodka Magdalena, Besnard Céline, Maroni Plinio, Trefalt Gregor, Borkovec Michal (2016), Dispersion forces acting between silica particles across water: influence of nanoscale roughness, in Nanoscale Horizons
, 1(4), 325-330.
Moazzami-Gudarzi Mohsen, Trefalt Gregor, Szilagyi Istvan, Maroni Plinio, Borkovec Michal (2016), Nanometer-ranged attraction induced by multivalent ions between similar and dissimilar surfaces probed using an atomic force microscope (AFM), in Physical Chemistry Chemical Physics
, 18(12), 8739-8751.
Tiraferri Alberto, Borkovec Michal (2015), Probing effects of polymer adsorption in colloidal particle suspensions by light scattering as relevant for the aquatic environment: An overview, in Science of The Total Environment
, 535, 131-140.
Moazzami Gudarzi Mohsen, Trefalt Gregor, Szilagyi Istvan, Maroni Plinio, Borkovec Michal (2015), Forces between Negatively Charged Interfaces in the Presence of Cationic Multivalent Oligoamines Measured with the Atomic Force Microscope, in The Journal of Physical Chemistry C
, 119(27), 15482-15490.
Montes Ruiz-Cabello F. Javier, Trefalt Gregor, Oncsik Tamas, Szilagyi Istvan, Maroni Plinio, Borkovec Michal (2015), Interaction Forces and Aggregation Rates of Colloidal Latex Particles in the Presence of Monovalent Counterions, in The Journal of Physical Chemistry B
, 119(25), 8184-8193.
Oncsik Tamas, Trefalt Gregor, Borkovec Michal, Szilagyi Istvan (2015), Specific Ion Effects on Particle Aggregation Induced by Monovalent Salts within the Hofmeister Series, in Langmuir
, 31(13), 3799-3807.
Tiraferri Alberto, Maroni Plinio, Borkovec Michal (2015), Adsorption of polyelectrolytes to like-charged substrates induced by multivalent counterions as exemplified by poly(styrene sulfonate) and silica, in Physical Chemistry Chemical Physics
, 17(16), 10348-10352.
Montes Ruiz-Cabello F. Javier, Moazzami-Gudarzi Mohsen, Elzbieciak-Wodka Magdalena, Maroni Plinio, Labbez Christophe, Borkovec Michal, Trefalt Gregor (2015), Long-ranged and soft interactions between charged colloidal particles induced by multivalent coions, in Soft Matter
, 11(8), 1562-1571.
Polyelectrolytes are widely used as additives to control properties of particle dispersions, such as their stability or rheology. In many applications, the polyelectrolytes used are oppositely charged than the substrates. In this case, strong electrostatic attraction between the polyelectrolytes and the substrates is dominant, and the adsorption mechanisms and the resulting forces between the substrates are understood reasonably well, in some situations even quantitatively. On the other hand, various successful applications rely on polyelectrolytes that have the same charge as the substrates. Interestingly, multivalent counterions, such as calcium, iron, or aluminium ions are frequently used in such formulations. The situation in such like-charged systems is hardly understood. Naively, one would expect that the strong electrostatic repulsive forces prevent adsorption completely. However, evidence exists that polyelectrolytes adsorb to like-charged substrates, and it was suggested that ion correlations may induce electrostatic attractive forces that are responsible for this phenomenon. Moreover, when the polyelectrolyte chains are repelled from the substrate, this repulsion leads to depletion interactions, which are further magnified by the structuring of the polyelectrolyte solution. In such like-charged systems, the interplay between forces described by the classical Derjaguin, Landau, Verwey, and Overbeek (DLVO) theory, which considers electric double layer and van der Waals forces, and non-DLVO forces, such as, ion correlation, depletion, and polymer induced forces remains unclear. The systematic elucidation of the underlying interaction mechanisms is the main goal of this project. The project will investigate different well-defined model systems, and explore the role of multivalent ions along three lines. (i) Study of conformation, charge, and eventual phase separation of polyelectrolytes in solution, (ii) investigation of polyelectrolyte adsorption to like-charged substrates, and (iii) direct force measurements. These phenomena will be explored experimentally with state-of-the-art techniques, in particular, light scattering, optical reflectivity, and atomic force microscopy. These measurements will be complemented with appropriate model calculations. The project will clarify the mechanism of interactions of polyelectrolyte near like-charged substrates, and is expected to have impact in academia and industry.