State-of-the-art axisymmetric drop shape analysis (ADSA) techniques for the computation of interfacial tensions and contact angles by fitting the Laplace equation of capillarity to the shape and dimensions of pendant and sessile drops are presented. More accurate, efficient, and reliable versions of the technique for the measurement of contact angles from the volume and diameter of sessile drop...

Droplet manipulation plays an important role in a wide range of scientific and industrial applications, such as synthesis of thin-film materials, control of interfacial reactions, and operation of digital microfluidics. Compared to micron-sized droplets, which are commonly considered as spherical beads, millimeter-sized droplets are generally deformable by gravity, thus introducing nonlinearity...

The methodology combining Axisymmetric Drop Shape Analysis (ADSA) with a captive bubble (ADSA-CB) facilitates pulmonary surfactant related studies. The accuracy of ADSA-CB is crucially dependent on the quality of the bubble profile extracted from the raw image. In a previous paper, an image analysis scheme featuring a Canny edge detector and a Axisymmetric Liquid Fluid Interfaces-Smoothing (ALF...

A new application of the axisymmetric drop shape analysis (ADSA) has been developed, using the pendant-drop film balance technology for penetration studies of insoluble monolayers at the liquid–liquid interface. A monolayer is spread on the surface of a drop of a buffer solution suspended from a capillary, which is the outer one of an arrangement of two coaxial capillaries connected to the two ...

The ultralow interfacial tension of the two-liquid phase of a ternary system 1-propanol–n-heptane–water was determined with a pendant drop method using the axisymmetric drop shape analysis (ADSA) methodology. Because the two liquid phases of the ternary system are practically miscible at temperatures near the critical solution temperature, the drops are small and difficult to distinguish from t...

A new method combining axisymmetric drop shape analysis (ADSA) and a captive bubble (CB) is proposed to study the effect of surfactant on interfacial gas transfer. In this method, gas transfer from a static CB to the surrounding quiescent liquid is continuously recorded for a short period (i.e., 5 min). By photographical analysis, ADSA-CB is capable of yielding detailed information pertinent to...

In the lungs, oxygen transfer from the inspired air to the capillary blood needs to cross the surfactant lining layer of the alveoli. Therefore, the gas transfer characteristics of lung surfactant film are of fundamental physiological interest. However, previous in vitro studies-most relied on the Langmuir-type balance-fail to cover the low surface tension range (i.e., less than the equilibrium...

PURPOSE To perform a surface chemistry study of the interactions between benzalkonium chloride (BAC), a common preservative used in ophthalmic formulations, and tear film (TF) constituents. METHODS The interactions between BAC and human tears, meibum, and rabbit corneal cell lipid extracts at the air-water interface were examined in vitro during controlled compression-expansion of the film ar...

PURPOSE To evaluate the shear bond strength of resin luting agent to dentin surfaces cleansed with different agents like pumice, ultrasonic scaler with chlorhexidine gluconate, EDTA and the influence of these cleansing methods on wetting properties of the dentin by Axisymmetric drop Shape Analysis - Contact Diameter technique (ADSA-CD). MATERIALS AND METHODS Forty coronal portions of human th...

Automatic surface tension measurement of turbid liquids using a bubble method (e.g., pendant/captive bubble) or interfacial tension measurement f some liquid–liquid systems necessitates an image analysis scheme robust against noise. Measuring the surface tension of lung surfactant–polymer ystems using the combination of axisymmetric drop shape analysis (ADSA) and a captive bubble is such an exa...