TY - EJOUR
DO - 10.1039/b602145j
AB - The Derjaguin approximation states that the interaction force between two curved surfaces is proportional to their effective radius, whereby the inverse effective radius is the arithmetic mean of the inverse curvature radii of the surfaces involved. The present study investigates the validity of this approximation with an atomic force microscope (AFM) by measuring interaction forces between colloidal particles of different sizes, but of identical composition. Forces were measured between silica particles of 2.0, 4.8 and 6.8 mu m in diameter in KCl electrolyte solution with and without adsorbed poly(amido amine) (PAMAM) dendrimers. The Derjaguin approximation could be confirmed at all distances investigated, including those comparable with the characteristic length scales of the surface roughness or the surface charge heterogeneities. For the conditions investigated, the Derjaguin approximation turns out to be surprisingly robust.
T1 - Probing the validity of the Derjaguin approximation for heterogeneous colloidal particles
DA - 2006
AU - Rentsch, S.
AU - Pericet-Camara, R.
AU - Papastavrou, G.
AU - Borkovec, M.
JF - Physical Chemistry Chemical Physics
SP - 2531-2538
VL - 8
EP - 2531-2538
PB - Royal Society of Chemistry
ID - 148753
KW - Direct Force Measurements
KW - Poisson-Boltzmann Theory
KW - Double-Layer Interaction
KW - Aqueous-Electrolyte
KW - Surface Forces
KW - Flat-Plate
KW - Poly(Amidoamine) Dendrimers
KW - Silica Particles
KW - Charged Surfaces
KW - derjaguin approximation
KW - colloidal probe microscopy
SN - 1463-9076
UR - http://infoscience.epfl.ch/record/148753/files/Rentsch_PCCP_2006.pdf
ER -