Polyelectrolytes as adhesion modifiers
2003 (English)In: Advances in Colloid and Interface Science, ISSN 0001-8686, E-ISSN 1873-3727, Vol. 104, 53-74 p.Article in journal (Refereed) Published
Adsorbed layers of polyelectrolytes have been studied with atomic force microscopy (AFM) and the interferometric surface force apparatus (SFA). Particular emphasis was put on determining the effect of the polyelectrolyte charge density on surface topography, and the effect of the polyelectrolyte coating on the adhesive properties. The AFM was employed to image individual polymer chains at low adsorption densities and to characterize the layer topography and coverage at higher adsorption densities. The adhesive properties between two polyelectrolyte-coated surfaces in air were determined as a function of the number of contacts made at any given spot. The data provide evidence for formation of electrostatic bridges, particularly when highly charged polyelectrolytes are used. Further, material transport between the surfaces is observed when the polyelectrolyte is either highly charged or have a very low charge density. For intermediate charge densities we could not observe any indication of material transfer. The adhesion between one polyelectrolyte-coated surface and one bare surface was initially higher than that between two polyelectrolyte-coated surfaces. However, due to material transfer between the two surfaces the adhesion decreased significantly with the number of times that the surfaces were driven into contact. For the polyelectrolytes of the lowest charge density the results suggest that entanglement effects contribute to the adhesive interaction. The modification of the adhesion by polyelectrolytes in practical systems such as in the case of dry-strength additives to improve paper resistance is also considered.
Place, publisher, year, edition, pages
2003. Vol. 104, 53-74 p.
adhesion, polyelectrolytes, AFM imaging, surface forces, dry-strength additives, paper strength, aqueous polyvinylamine solutions, atomic-force microscopy, rate-dependent adhesion, surface forces, charge-density, cationic polyelectrolyte, glass surfaces, contact deformations, elastic particles, coated surfaces
IdentifiersURN: urn:nbn:se:kth:diva-22618ISI: 000183732300006OAI: oai:DiVA.org:kth-22618DiVA: diva2:341316
QC 201005252010-08-102010-08-10Bibliographically approved