J. Drelich et al., Limitation of the Young-Dupre equation in the analysis of adhesion forces involving surfactant solutions, J ADHESION, 74(1-4), 2000, pp. 361-371
The atomic Force microscope was used to measure adhesion forces between pol
yethylene particles, serving as model oil droplets. and mineral substrates
(fluorite and quartz) in aqueous solutions of ethoxylated alcohols. Also. c
ontact angles were measured in the kerosene ethoxylated alcohol solution-mi
neral systems. Correlations obtained between adhesion and surfactant concen
tration for the polyethylene -aqueous solution-quartz system differs signif
icantly from those predicted by the Young-Dupre equation For the kerosene-a
queous solution-quartz system. Interactions, characteristic for such aqueou
s systems, which contribute to the pull-off forces measured by atomic force
microscopy are nor included in the Young-Dupre equation, and are primarily
responsible for the inconsistency in the adhesion versus surfactant concen
tration relationship obtained from contact angle measurements.