ADHESION OF A SOFT RUBBER ON A WET SOLID

We study theoretically the dewetting of a liquid film intercalated bet ween a flat solid and a weakly crosslinked rubber. The rubber is chara cterised by a static shear modulus, mu(0) a high frequency modulus, mu (infinity)(>>mu 0) and a relaxation time, T. The film dewets by nuclea tion and growth of a dry contact zone (radius R(t) at time i) surround ed by a liquid rim collecting the liquid. We expect three regimes: a) at short times (R < R-c1), the rubber behaves like a hard elastic soli d (mu = mu(infinity)) and the dissipation is dominated by the liquid r im. We call this fast elastic dewetting. b) at intermediate times (R-c 1 < R < R-c2), the rubber behaves like an ultra-viscous liquid. We cal l this ''mixed viscous dewetting'' because both components dissipate. c) at long times (R > R-c2) the rubber behaves like a soft solid (mu = mu(0)) and the liquid dissipation is again dominant. We call this slo w elastic dewetting.