Chemocapillary instabilities of a contact line.
Equilibrium and motion of a contact line are viewed as analogs of phase equilibrium and motion of an interphase boundary. This point of view makes evident the tendency to minimization of the length of the contact line at equilibrium. The concept of line tension is, however, of limited applicability, in view of a qualitatively different relaxation response of the contact line, compared to a two-dimensional curve. Both the analogy and qualitative distinction extend to a nonequilibrium situation arising due to coupling with reversible substrate modification. Under these conditions, the contact line may suffer a variety of chemocapillary instabilities (fingering, traveling, and oscillatory), similar to those of dissipative structures in nonlinear nonequilibrium systems. The preference order of the various instabilities changes, however, significantly due to a different way the interfacial curvature is relaxed.
Pismen
L M
LM
Department of Chemical Engineering and Minerva Center for Nonlinear Physics of Complex Systems, Technion-Israel Institute of Technology, Haifa 32000, Israel.