Simple, accurate method for contact angle measurement tech briefs. For a known drop volume, the contact angle can be derived from a measurement of the drop diameter. Quick tutorial on using imagej to process contact angle data. Contact angle measurement tool based on image analysis. Contact angle measurements using cellphone cameras to. Instantly displays statistical values of average and standard deviation as the data is entered. Contact angle is often the most direct indication that a surface is contaminated and is sometimes overlooked as a very surfacesensitive analysis tool. Guidelines to measurements of reproducible contact angles using a sessiledrop technique article in surface innovations 14.
Contact angle measurement equipment uk dyne testing. The impact of contact angle on the biocompatibility of. Also, measurement is used by software engineers to gain insight into the design and development of the work products. The database design with quick access to measurements and results is also clearly arranged. The contact angle plugin is designed to provide angles for images with the droplets upside down. Engineering water repellency involves modifying the surface of cfa particles with organosilane os. Contact angle measurement using imaging method youtube. They determine which coatings are best to cause a surface to shed water quickly or to reduce the fogging caused by condensation. Klonk image measurement, free, software, tool, image. Contact angle measurement has been broadly accepted for material surface analysis related to wetting, adhesion, and absorption.
Contact angle is one of the common ways to measure. Contact angle goniometer, low price measurement instrument. Using the bikerman equation, the contact angle of a sessile drop can be measured from above. Static contact angles are utilized in quality control and in research and product development.
Contact angle measurements using the drop shape method. Free software for high precision contact angle measurement. Follow 69 views last 30 days voon loong on 19 aug 2012. In zdirection the sample table is adjustable using precision mechanics with a hand wheel. A more precise method measures b and h by drawing a rectangle that connects the triphase points and the apex of the drop 2 manual methods using digital images computer graphics software packages and usb.
The force acting in the tensile direction when moving a plateshaped solid vertically in a. Using the contact angle meter you can compare the effects of a range of surface treatments and gather data that correlates to various surface conditions e. With a rich suite of measurement and reporting features, it is the right measurement tool for a broad range of applications, from electronics and aerospace to. Increased accuracy can be achieved using lowcost close. Guidelines to measurements of reproducible contact angles. Introduction its about 200 years ago since young described the role of surface tension, i. Contact angles were estimated with a goniometer equipped with a special optical system and a ccd camera obtained from the institute of applied optics in warsaw. Contact angle measurement combines high technology test instrumentation and a nondestructive testing method to allow an accurate, objective and repeatable analysis to be made. Dsa100, dsa30, dsa25, msa, mobiledrop wilhelmy plate method. How to determine hydrophilicity and hydrophobicity of a. This is small compared to the variances from spot to spot on most surfaces, and it is also small compared to the uncertainties in current theory for converting contact angles to surface energies. After fabricating the surfaces, the next step was obtaining the contact angle of a droplet for each of the sample.
The theoretically predicted minimum in the curve of receding contact angle vs. Assessing the accuracy of contact angle measurements for sessile drops on liquidrepellent surfaces siddarth srinivasan, gareth h. Contact angle is a simple and yet powerful tool for characterizing threephase. Simple and lowcost contact angle measurements using a. The angle of contact is one way to measure and assess the. A given system of solid, liquid, and vapor at a given temperature and pressure has a unique equilibrium contact angle. Mathworks is the leading developer of mathematical computing software for engineers and scientists. The instrument of choice to measure contact angles and dynamic contact angles is an optical tensiometer.
However, in practice a dynamic phenomenon of contact angle. The contact angle displays hysteresis based on direction of motion of the interface. Utilization of a surface balance provides information on the product of the interfacial tension and the contact angle. Contact angle measurement software ca measure tool. Smartphonebased surface tension and contact angle measurement duration. Assessing the accuracy of contact angle measurements for. The necessity to have a selfdeveloped software comes by considering that commercial softwares do not provide a sufficient enough description of the methods used in their contact angle calculation. Results indicate that the extent of water repellency can be quantified more accurately with contact angle ca measurements determined by increasing a drop size until the threephase contact line motion becomes approximately constant. Application notes and software about contact angle meter, drop. Methods for the calculation of surface free energy of solids, journal of achievements in materials and manufacturing engineering 2007. The contact angle method works fine for nonporous polymers and samples.
Surface roughness affects the equilibrium contact angle, so measurements are typically made on smooth, flat surfaces. Measure length, area, angle and circumference you can measure both the length, area, circumference or angle of an object with image measurement. The software is based on a plugin for imagej, a general purpose free imageprocessing package. The system integrates contact angle and surface energy evaluation with computer imaging technology to create an easy to use tool that provides accurate, objective results. Surface free energy determination by contact angle. Figure 1 contact angle measurement tool features and specifications measuring range. In fact people often perform contact angle measurements, by applying the sphere approximation, neglecting in this way the gravity effect, or by. Shape analysis based interfacial chemistry measurement system c60. Drop shape analysis for surface tension and contact angle measurements of sessile drops, colloids and surfaces a. But determination of surface energy of solids from contact angle measurements faces the presence of one more unknown quantity in the youngs equation, the interfacial energy. Contact angle measurements anderson materials evaluation. Contact angle measuring instrument dsa100 processor tensiometer k100 with care to accuracy. New, innovative software advance drop shape for contact angle. The experimental setup for the contact angle measurement is shown in figure 1a.
Contact angle measurements can be precise, but even for ideal systems, measurements can show significant variation. Sandip patil, in nano and microscale drug delivery systems, 2017. Test liquid room temperature surface tension mnm contact angle on polyethylene degrees nhexane 18. This instrument has been furnished with a 4 rotating wafer support stage and automated tilting base option. Track the development of your measurements with image measurement and generate reports to use for documentation. We present a cheap solution for assessment of contact angles on sessile drops or menisci formed around partially submerged fibers. Contact angle measurement using the half angle method of drawing a line from the triphase point to the apex of the drop. Measure the contact angle of the drop in the image e. Measurement helps in estimation, quality control, productivity assessment and project control throughout a software project. Contact angle hysteresis advances in chemistry acs. In addition, measurement assists in strategic decisionmaking as a project proceeds.
The plasticizer droplet is shown here with the analysis used to measure the contact angle. Contact angle measurement georgia tech biocleanroom. The contact angle is measured using the image of a sessile drop at the points of intersection threephase contact points between the drop contour and the projection of the surface. A characteristic that significantly influences this response is that related to surface wettability, which is often determined by measuring the contact angle of the material. The georgia tech contact angle measurement device goniometer, located in the biocleanroom, is a software driven instrument providing automated digital contact angle measurements. The oca 15ec is the entry level measuring device for professional contact angle measurements and drop shape analysis. The method of contact angle measurements and estimation of. Yu and ziegler 160 characterized the cls using a ccm. A bespoke contact angle measurement software and experimental.
Refined software makes this an affordable solution to many industrial and academic measurement tasks. The successful demonstration of use of a smartphone mobile phone to conduct contact angle measurement is a significant advancement in the field as it breaks the dominate mold of use of a computer and a bench bound setup for such systems since their appearance in 1980s. Windows image processing software for measurement of contact angle of liquids on solids. All data can be printed, saved andor exported for further analysis or graphing in other software programs. The theoretical wettability behavior of an idealized, rough surface agrees well with that of real surfaces. Both optical and force tensiometers enable static and dynamic contact angle measurements. The ca measure tool software was built in the matlab integrated development environment as shown in fig. Variations are related to surface preparation, equilibration of the solid and liquids, and surface roughness. The fully automatic assessment of contact angles is based on image binarization, identification of regions of interest, boundary smoothing, and contour. The contact angle is the angle, conventionally measured through the liquid, where a liquidvapor interface meets a solid surface. It quantifies the wettability of a solid surface by a liquid via the young equation. The proposed system consists of a simple optical set combined with an opensource software camtia. Astm d7490 standard test method for measurement of the surface tension of solid coatings, substrates and pigments using contact angle measurements.
Swift pro duo provides fast and accurate measurement of both routine and complex precision parts. The model 250 is also a tensiometer and has an advanced software version for surface energy measurements. The water droplet is shown here as analyzed to measure the contact angle. It is shown how this method can be implemented with many currentlyavailable cellphone models. Static contact angles are measured when droplet is standing on the surface and the. You can take picture of any object that you would like to measure, for example, a car, road, house, stairs or a mountain, the protractor is transparent, after you uploaded the image, it will be display in the background. Oca optical contact angle measuring and contour analysis. They found that the first attachment of a water droplet at the cl surface showed a relatively high contact angle, and then the contact angle decreased with time, as shown in figure 3.
The angle is measured from the solid surface through the aqueous phase, or in an oil and gas test through the oil phase. Other analytical methods such as infrared microscopy would be needed to identify the chemical moieties that give the contact angle differences. The sample table of the oca 15ec can slide freely in x and ydirection and is locked into position with its switchable magnetic base. In addition, some of these techniques require expensive computer software to. However for more complex materials, porous and those that need to be pressed into a pellet, such as powders and fibers the.