Adhesive Interaction in Aqueous Media

Wong et al. [131] measured directly the interaction potential between a tethered ligand and its receptor in aqueous media. Using a surface force apparatus, the interaction force-distance profile was determined between streptavidin immobilized on a lipid bilayer and biotin tethered to the distal end of lipid-PEG. Both lipid bilayers containing streptavidin and biotin were absorbed onto the surface of mica having a specific curvature. Both cationic and anionic polymer grafted 

Yoshikimi Uyama, Koichi Kato, Yoshito Ikada 

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In aqueous media, the same as in air, hydrophobization of the surface to increase the wetting angle, i.e., to lower the value of the cosine of this angle, reduces the magnitude of adhesive interaction. 

Now, we will turn our attention to experimental studies on contact interactions in the presence of surfactants. Here, we will also devote special attention to the studies involving molecularly smooth surfaces, which allow one to quantitatively estimate the free energy of interaction as the main invariant parameter characterizing adhesion. We will also look at polar and nonpolar particles in various aqueous and nonaqueous media but focus on the role of the presence of small amounts of different surfactants. 

The sedimentation volume method is a well-established technique for studying the suspension stability of powders in liquids. The behaviour of such systems is governed mainly by van der Waals and electrostatic interactions. It is important to note that the former interactions can be related to the interfacial tensions of the solid particles suspended in a liquid (61), whereas the effect of the latter interactions can be considered negligible, e.g. for polymer particles, particularly in non-aqueous media (62). When two solid particles are brought into contact and if only van der Waals forces are considered, the free energy of adhesion of two solid phases in a liquid can be determined as follows ... 

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