Influence of line tension on spherical colloidal particles at liquid-vapor interfaces

• Published in: Physical review letters Vol. 109; no. 19; p. 196101
• Main Authors: McBride, Sean P, Law, Bruce M
• Format: Journal Article
• Language: English
• Published: United States 07.11.2012
• ISSN: 1079-7114
• DOI: 10.1103/physrevlett.109.196101

Atomic force microscopy (AFM) imaging of isolated submicron dodecyltrichlorosilane coated silica spheres, immobilized at the liquid polystyrene- (PS-) air interface at the PS glass transition temperature, T(g), allows for determination of the contact angle θ versus particle radius R. At T(g), all θ versus R measurements are well described by the modified Young's equation for a line tension τ = 0.93 nN. The AFM measurements are also consistent with a minimum contact angle θ(min) and minimum radius R(min), below which single isolated silica spheres cannot exist at the PS-air interface.