Surface stress and gravitational force have significant effects on the deformation of soft elastomers. By considering surface stress and gravity of the soft elastomer, we study wetting behaviors of soap bubbles on a semi-space elastomer through the surface Green’s function method. The normal surface displacement of the elastomer caused by the surface tension and Laplace pressure is calculated. The normal surface displacement in the contact zone monotonously increases from the center to the triple line, and the contact zone is divided into concave zone and convex zone. The results show that surface stress and gravity have significant influence on the normal surface deformation caused by the wetting of the soap bubble. In general, surface stress and gravity suppress the amplitude of the normal surface displacement. With the increase of surface stress, the amplitude of the normal surface displacement in the concave and convex zones decreases. However, with the increase of gravity, the amplitude of the normal surface displacement in the concave zone decreases, while that in the convex zone increases. This counterintuitive phenomenon can be understood by the superimposition of displacements. The results have potential applications in the fields of adhesion, indentation, evaporation, cell migration on soft materials, etc.
ArscottS.Wetting of soap bubbles on hydrophilic, hydrophobic, and superhydrophobic surfaces. Appl Phys Lett2013; 102: 254103.
2.
KimSHParkHSKoD, et al. Wetting characteristic of bubble on micro-pillar structured surface under a water pool. Exp Therm Fluid Sci2019; 100: 135–143.
3.
TeixeiraMACTeixeiraPIC.Contact angle of a hemispherical bubble: an analytical approach. J Colloid Interface Sci2009; 338: 193–200.
4.
KornekUMüllerFHarthK, et al. Oscillations of soap bubbles. New J Phys2010; 12: 073031.
5.
GeorgiouTBritnellLBlakeP, et al. Graphene bubbles with controllable curvature. Appl Phys Lett2011; 99: 093103.
6.
OchiaiYOyamaAToyoshimaK.A colloidal display: membrane screen that combines transparency, BRDF and 3D volume. In: ACM SIGGRAPH 2012 posters, 2012.
7.
HaziGMarkusA.On the bubble departure diameter and release frequency based on numerical simulation results. Int J Heat Mass Transfer2009; 52: 1472–1480.
8.
PhanHTCaneyNMartyP, et al. Surface wettability control by nanocoating: the effects on pool boiling heat transfer and nucleation mechanism. Int J Heat Mass Transfer2009; 52: 5459–5471.
9.
PhanHTCaneyNMartyP, et al. A model to predict the effect of contact angle on the bubble departure diameter during heterogeneous boiling. Int Commun Heat Mass Transfer2010; 37: 964–969.
10.
HaradaTNagakuraHOkawaT.Dependence of bubble behavior in subcooled boiling on surface wettability. Nucl Eng Des2010; 240: 3949–3955.
11.
Montes Ruiz-CabelloFJRodriguez-ValverdeMAMarmurA, et al. Comparison of sessile drop and captive bubble methods on rough homogeneous surfaces: a numerical study. Langmuir2011; 27: 9638–9643.
12.
NikolayevVSJanečekV.Impact of the apparent contact angle on the bubble departure at boiling. Int J Heat Mass Transfer2012; 55: 7352–7354.
13.
KalagaDVPantHJDalviSV, et al. Investigation of hydrodynamics in bubble column with internals using radioactive particle tracking (RPT). AIChE J2017; 63: 4881–4894.
14.
McHaleGShirtcliffeNJNewtonMI.Super-hydrophobic and super-wetting surfaces: analytical potential. Analyst2004; 129: 284–287.
15.
KangHCJacobiAM.Equilibrium contact angles of liquid droplets on ideal rough solids. Langmuir2011; 27: 14910–14918.
16.
ProkopRMJyotiAEslamianM, et al. A study of captive bubbles with axisymmetric drop shape analysis. Colloid Surf A1998; 131: 231–247.
17.
AbdelwahedMABWielhorskiYBizetL, et al. Characterisation of bubbles formed in a cylindrical T-shaped junction device. Chem Eng Sci2012; 76: 206–215.
18.
YinKYangSDongX, et al. Femtosecond laser fabrication of shape-gradient platform: underwater bubbles continuous self-driven and unidirectional transportation. Appl Surf Sci2019; 471: 999–1004.
19.
LiWJZhangJJXueZX, et al. Spontaneous and directional bubble transport on porous copper wires with complex shapes in aqueous media. ACS Appl Mater Interfaces2018; 10: 3076–3081.
20.
ThombareMAChavanPVBankarSB, et al. Solid-liquid circulating fluidized bed: a way forward. Rev Chem Eng2018; 35: 1–44.
21.
ZhuJStoyanovHKofodG, et al. Large deformation and electromechanical instability of a dielectric elastomer tube actuator. J Appl Phys2010; 108: 074113.
22.
TanakaTSunSTHirokawaY, et al. Mechanical instability of gels at the phase transition. Nature1987; 325: 796–798.
23.
BiotMA.Surface instability of rubber in compression. Appl Sci Res Sect A1963; 12: 168–182.
24.
GentANChoIS.Surface instabilities in compressed or bent rubber blocks. Rubber Chem Technol1999; 72: 253–262.
25.
BedarkarAWuXFVaynbergA.Wetting of liquid droplets on two parallel filaments. Appl Surf Sci2010; 256: 7260–7264.
26.
LubardaVA.Mechanics of a liquid drop deposited on a solid substrate. Soft Matter2012; 8: 10288–10297.
27.
DervauxJAmarMB.Mechanical instabilities of gels. Annu Rev Condens Matter Phys2012; 3: 311–332.
28.
KimJHannaJAByunM, et al. Designing responsive buckled surfaces by halftone gel lithography. Science2012; 335: 1201–1205.
29.
KeplingerCLiTBaumgartnerR, et al. Harnessing snap-through instability in soft dielectrics to achieve giant voltage-triggered deformation. Soft Matter2012; 8: 285–288.
30.
WangQZhaoX.Creasing-wrinkling transition in elastomer films under electric fields. Phys Rev E2013; 88: 042403.
31.
RusanovAI.On the thermodynamics of deformable solid surfaces. J Colloid Interface Sci1978; 63: 330–345.
32.
LiKGeDCaiS.Gravity-induced wrinkling of thin films on soft substrates. EPL2012; 100: 54004.
ZhengYCrosbyAJCaiS.Indentation of a stretched elastomer. J Mech Phys Solids2017; 107: 145–159.
45.
DuJChenXLiangX, et al. Integrin activation and internalization on soft ECM as a mechanism of induction of stem cell differentiation by ECM elasticity. Proc Natl Acad Sci2011; 108: 9466–9471.
