Line tension at wetting: interface displacement model beyond the gradient-squared approximation

✍ Scribed by H.T. Dobbs; J.O. Indekeu

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 956 KB
• Volume: 201
• Category: Article
• ISSN: 0378-4371
• DOI: 10.1016/0378-4371(93)90120-s

✦ Synopsis

We study the transition zone or contact line between a thin film and bulk liquid, and calculate the line tension r, employing an interface displacement model equivalent to Derjaguin's and de Gennes' approach. We investigate the behaviour of ~" in the limit that the contact angle 0 tends to zero, approaching a wetting phase transition. Previous results for wetting and prewetting, derived in the gradient-squared approximation of the model, remain valid when the gradient is included to all orders. The interesting singular behaviour of r at wetting is universal, due to the critical phenomena that have recently been found to underly first-order as well as continuous wetting transitions. Finally we critically review two contactline instabilities that have been associated with contact-angle hysteresis, and propose an alternative physical interpretation.