Capillary Bridges on Hydrophobic Surfaces: Analytical Contact Angle Determination

The capillary bridge probe method was introduced previously as a high-accuracy contact angle determination method relying on capillary bridges on hydrophilic and superhydrophilic surfaces [Nagy, N. Langmuir2019, 35 ( (15), ), 5202−521230916567]. In this work, the behavior of r-ϑ type liquid bridges was studied and the contact angles were determined on hydrophobic surfaces. The equilibrium shape of these liquid bridges often does not contain the neck or haunch region. The unknown neck/haunch radius prevents analytical evaluation of the capillary bridge shape. In this work, the possible incomplete liquid bridge shapes were classified and a novel procedure was developed for the Delaunay’s analytical solution-based evaluation of these states. The parameter space of the capillary bridges was visualized and described without using dimensionless variables. As a demonstration, Cyclo Olefin Polymer and PTFE surfaces were investigated, with advancing and receding contact angles determined and compared to the results of sessile drop measurements.

[1]  N. Pesika,et al.  Determination of the Sliding Angle of Water Drops on Surfaces from Friction Force Measurements , 2022, Langmuir : the ACS journal of surfaces and colloids.

[2]  J. Drelich,et al.  Water droplets and air bubbles at magnesite nano-rough surfaces: Analysis of induction time, adhesion and detachment using a dynamic microbalance , 2020 .

[3]  Z. Hajnal,et al.  Robust Contact Angle Determination for Needle-in-Drop Type Measurements , 2019, ACS omega.

[4]  V. Sariola.  Analytical Expressions for Spring Constants of Capillary Bridges and Snap-in Forces of Hydrophobic Surfaces , 2019, Langmuir : the ACS journal of surfaces and colloids.

[5]  N. Nagy.  Contact Angle Determination on Hydrophilic and Superhydrophilic Surfaces by Using r-θ-Type Capillary Bridges. , 2019, Langmuir : the ACS journal of surfaces and colloids.

[6]  Robin H. A. Ras,et al.  Improving surface-wetting characterization , 2019, Science.

[7]  J. Drelich.  Contact angles: From past mistakes to new developments through liquid-solid adhesion measurements. , 2019, Advances in colloid and interface science.

[8]  Chang‐Hwan Choi,et al.  The most stable state of a droplet on anisotropic patterns: support for a missing link , 2018, Surface Innovations.

[9]  C. Volpe,et al.  The Wilhelmy method: a critical and practical review , 2018, Surface Innovations.

[10]  Dorian A. H. Hanaor,et al.  Dynamic contact angle hysteresis in liquid bridges , 2017, Colloids and Surfaces A: Physicochemical and Engineering Aspects.

[11]  Robin H. A. Ras,et al.  Mapping microscale wetting variations on biological and synthetic water-repellent surfaces , 2017, Nature Communications.

[12]  LiuQingxia,et al.  Direct measurements of adhesion forces of water droplets on smooth and patterned polymers , 2017 .

[13]  G. Lian,et al.  The capillary bridge between two spheres: New closed-form equations in a two century old problem. , 2016, Advances in colloid and interface science.

[14]  Satish Kumar.  Liquid Transfer in Printing Processes: Liquid Bridges with Moving Contact Lines , 2015 .

[15]  O. Millet,et al.  Analytic Calculation of Capillary Bridge Properties Deduced as an Inverse Problem from Experimental Data , 2014, Transport in Porous Media.

[16]  Shi-Yow Lin,et al.  On the uniqueness of the receding contact angle: effects of substrate roughness and humidity on evaporation of water drops. , 2014, Langmuir : the ACS journal of surfaces and colloids.

[17]  A. Amirfazli,et al.  Liquid transfer mechanism between two surfaces and the role of contact angles. , 2014, Soft matter.

[18]  J. Drelich.  Guidelines to measurements of reproducible contact angles using a sessile-drop technique , 2013 .

[19]  Stephen Michielsen,et al.  Symmetric and asymmetric capillary bridges between a rough surface and a parallel surface. , 2013, Langmuir : the ACS journal of surfaces and colloids.

[20]  E. Bormashenko.  Wetting of Real Surfaces , 2013 .

[21]  A. Amirfazli,et al.  Modeling liquid bridge between surfaces with contact angle hysteresis. , 2013, Langmuir : the ACS journal of surfaces and colloids.

[22]  H. Erbil,et al.  Evaporation of pure liquid sessile and spherical suspended drops: a review. , 2012, Advances in colloid and interface science.

[23]  Kock-Yee Law,et al.  Study of Wetting and Adhesion Interactions between Water and Various Polymer and Superhydrophobic Surfaces , 2011 .

[24]  E. Bormashenko,et al.  Evaporation of droplets on strong and low-pinning surfaces and dynamics of the triple line , 2011, 1102.4499.

[25]  L. Léger,et al.  Wetting and dewetting transition: an efficient toolbox for characterizing low-energy surfaces. , 2010, Langmuir : the ACS journal of surfaces and colloids.

[26]  A. Cazabat,et al.  Evaporation of macroscopic sessile droplets , 2010 .

[27]  L. Léger,et al.  Contact angle and contact angle hysteresis measurements using the capillary bridge technique. , 2009, Langmuir : the ACS journal of surfaces and colloids.

[28]  C Mohrdieck,et al.  Capillary forces between chemically different substrates. , 2008, Langmuir : the ACS journal of surfaces and colloids.

[29]  E. Arzt,et al.  Effect of contact angle hysteresis on the measurement of capillary forces. , 2008, Langmuir : the ACS journal of surfaces and colloids.

[30]  M. A. Fortes,et al.  Axisymmetric liquid bridges between parallel plates , 1982 .

[31]  W. Zisman,et al.  The spreading of liquids on low-energy surfaces. IV. Monolayer coatings on platinum , 1952 .