Desorption of bottle-brush polyelectrolytes from silica by addition of linear polyelectrolytes studied by QCM-D and reflectometry
2008 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 323, no 2, 223-228 p.Article in journal (Refereed) Published
The possibility of exchanging adsorbed layers of PEO(45)MEMA:METAC-X brush polyelectrolytes (with two different charge densities, 10 and 75 mol%, denoted by X), with poly(MAPTAC), a highly charged linear polyelectrolyte, was investigated by quartz crystal microbalance with dissipation and reflectometry. The studies were conducted on a silica substrate at pH 10, conditions under which only electrostatic interactions are effective in the adsorption process. Based on the results, it was concluded that PEO(45)MEMA:METAC-10 forms an inhomogeneous layer at the interface through which poly(MAPTAC) chains can easily diffuse to reach the surface. On the other hand, the PEO(45)MEMA:METAC-75 layer was not affected when exposed to a poly(MAPTAC) solution. We argue that the observed effect for PEO(45)MEMA: METAC-75 is due to the formation of a homogeneous protective brush layer, in combination with the small difference in surface affinity between the bottle-brush polyelectrolyte and poly(MAPTAC), together with the difficulty of displacing highly charged polyelectrolyte chains once they are adsorbed on the oppositely charged surface. We also use the combination of QCM-D and reflectometry data to calculate the Water content and layer thickness of the adsorbed layers. (c) 2008 Elsevier Inc. All rights reserved.
Place, publisher, year, edition, pages
2008. Vol. 323, no 2, 223-228 p.
polyelectrolyte, bottle-brush polyelectrolyte, brush polyelectrolyte, comb polyelectrolyte, linear polyelectrolyte, charge density, side chain density, poly(ethylene oxide), QCM-D, reflectometry, silica, adsorbed mass, sensed mass, dissipation, adsorption, desorption, QUARTZ-CRYSTAL MICROBALANCE, CHARGE-DENSITY, SIDE-CHAIN, CATIONIC POLYELECTROLYTES, COMPETITIVE ADSORPTION, PROTEIN ADSORPTION, POLYMERS, KINETICS, LAYERS, FILMS
IdentifiersURN: urn:nbn:se:kth:diva-14001DOI: 10.1016/j.jcis.2008.04.022ISI: 000256743300004ScopusID: 2-s2.0-44649186817OAI: oai:DiVA.org:kth-14001DiVA: diva2:328965