Capillary instabilities by fluctuation induced forces

Abstract

The spontaneous break-up of thin films is commonly attributed to the destabilizing effect of van der Waals forces. Dispersion forces can be considered in terms of the confinement of the electromagnetic fluctuation spectrum. The principle of confinement is more general than the usual argument of interacting dipole fluctuations. It includes also disjoining pressures that are caused by thermal fluctuations. In this context, we review recent publications on the dewetting of thin polymer films, and argue that the presence of an acoustic disjoining pressure is necessary to adequately describe some of these experimental results.

The competition between the liquid-liquid dewetting and the liquid-solid dewetting

“…Recently, many papers have reported the dewetting process of polymer bilayers by experiments, simulations, and theories and have shown richer dynamics and dewetting pathways. [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] The evolution of polymer bilayers is driven by the effective molecular interactions between all the three interfaces separating the four media: substrate, the lower layer, the upper layer, and surrounding gas ͑air͒. Many experiments have reported that only the upper layer can dewet on the liquid substrate and only the lower layer dewets between the upper layer and the solid substrate.…”

Mean-field description of spinodal growth of surface waves on rupturing films

“…However, alternative origins of G(h 0 ) have also been proposed [15,[20][21][22][23]. By assuming the non-retarded vdW potential for G(h 0 ), namely Gðh 0 Þ ¼ ÀA=12ph 2 0 where A is the Hamaker constant, and substituting it in Eqs.…”

“…In Fig. 2 is plotted G 0 0 (h 0 ) for air-PS-SiO x -Si assuming several origins proposed of G(h 0 ), including the non-retarded vdW interactions [6], full vdW interactions [15] and the confined phonon fluctuation field [20,21]. As seen, for all these origins assumed of G(h 0 ), the spinodal G 00 (h 0 ) = 0 occurs at h 0 P 160 nm, showing the h 0 = 3 nm film chosen for this study to lie well inside the spinodal region on theoretical grounds.…”

“…The inset is a magnification of the panel. G phonon (T) denotes the interfacial potential due to a confined phonon fluctuation field at temperature T[20,21]. The data are obtained by the simulation method detailed in Ref [15]…”

Electrohydrodynamic instability of a dielectric compressible liquid sheet streaming into an ambient stationary compressible gas

“…Among others, Melcher [3], Morariu et al [4], Parkin [5], and Turnbull [6] have studied the influence of charge on the jet breakup. Turnbull [6] assumed an insulating liquid, where Melcher [3] assumed the jet to be a perfect conductor.…”