METHOD FOR DETERMINATION OF INTERFACIAL SURFACE TENSION AND CONTACT ANGLE BY THE METHOD OF EXPANDED MENISCUS

摘要

The invention relates to measuring technique. A method for determination of interfacial surface tension and contact angle by the method of expanded meniscus includes measurement of weight of liquid in formed meniscus round the cylinder made of solid body under investigation at immersion of its lower end to the liquid under investigation, with determination of height of elevation of the meniscus on the cylindrical surface of the vertical cylinder. According to the invention experimental profile of expanded meniscus at the liquid-gas interface is obtained by means of parallel light source, light-sensitive matrix and device for reception and transfer of signal from the light-sensitive matrix. Data on experimental profile of meniscus obtained are digitalized by means of personal computer. On the basis of the results of digitalization height of elevation of the meniscus is calculated, with calculation of coordinates of obtained without quality, or absent sections of all the experimental profile from the side surface of the vertical cylinder to horizontal surface of liquid under investigation, those are taken into account at following calculations. Then through change of the values of surface tension and contact angle theoretical profile of the whole expanded meniscus that corresponds to the whole experimental contour of the expanded meniscus is calculated. The values of those parameters that correspond to calculated theoretical profile of the whole extended meniscus are taken as a value of surface tension and contact angle. The method provides increase of accuracy due to decrease of the errors of measurements.