Start Publications Specific Z-Potential Response of Layer-by-Layer Coated ...
QSense

Specific Z-Potential Response of Layer-by-Layer Coated Colloidal Particles Triggered by Polyelectrolyte Ion Interactions

Year: 2009

Journal: Langmuir, 2009, 25 (6), pp 3374–3380, 20100827

Authors: Irigoyen J. †, Moya S. E. *†, Iturri J. J. †, Llarena I. †, Azzaroni O. ‡, Donath E. §

Last authors: E. Donath

Organizations: CIC biomaGUNE, Paseo Miramon 182 Ed. Empresarial C, 20006 San Sebastian, Guipuzcoa, Spain, Instituto de Investigaciones Fisicoqulmicas Teoricas y Aplicadas (INIFTA), Universidad Nacional de La Plata, CONICET La Plata, Argentina, Institute of Biophysics and Medical Physics, Faculty of Medicine, University of Leipzig, Leipzig, Germany, and FideNa::PrincipiaTech Navarra, Campus Arrosadia (Edificio CIDEC) Calle Tajonar s/n, 31006 Pamplona, Navarra, Spain

Country: Spain

The ζ-potential of PSS/PAH and PSS/PDADMAC coated silica particles was studied in the presence of ClO4− and H2PO4− salts. In the presence of ClO4−, layer-by-layer (LbL) coated silica particles with PDADMAC as the top layer show a reversal in the surface charge with increasing salt concentration but remain positive in phosphate solutions. LbL particles with PAH as the top layer become, however, negative in the presence of H2PO4− but retain their positive charge in the presence of ClO4−. Charge reversal was explained by specific interaction of ClO4− ions with the quaternary amine groups and of H2PO4− with the primary amines through hydrogen bonding. Atomic force microscopy (AFM) and quartz crystal microbalance with dissipation (QCM-D) were employed to study the corresponding layer stability on planar surfaces.