Spreading of Latex Particles on a Substrate

– We have investigated both experimentally and theoretically the spreading behavior of latex particles deposited on solid substrates. These particles, which are composed of cross-linked polymer chains, have an intrinsic elastic modulus. We show that the elasticity must be considered to account for the observed contact angle between the particle and the solid substrate, as measured through atomic force microscopy techniques. In particular, the work of adhesion computed within our model can be significantly larger than that from the classical Dupré formula. Introduction. – Adhesion phenomena are of great importance in science and technology[1, 2]. The classical approach to describe the adhesion between two elastic bodies under a compressive force is given by the Johnson, Kendall, and Roberts (JKR) theory[3]. It is essentially an extension of the Hertz theory of elastic contact, allowing for a tensile stress to develop inside contact area to account for the effect of adhesion. For an adhesive sphere of radius R in contact with a flat solid substrate, the JKR theory predicts that the deformation of the sphere at the center of the contact area is δ = a 2