Open AccessSimultaneous measurement of liquid surface tension and contact angle by light reflection
Author(s) -
Dijun Luo,
Lailai Qian,
Liangwei Dong,
Peng Shao,
Zongmin Yue,
Juan Wang,
Bo Shi,
Shengbo Wu,
Yipan Qin
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.016703
Subject(s) - optics , collimated light , total internal reflection , materials science , surface tension , wetting , contact angle , reflection (computer programming) , beam expander , angle of incidence (optics) , beam (structure) , laser , laser beams , physics , composite material , quantum mechanics , computer science , programming language
We present an optical method of simultaneous measurement of liquid surface tension, contact angle, and the curved liquid surface shape, which uses the light reflection from this liquid surface due to the wettability. When an expanded and collimated laser beam is incident upon the curved liquid surfaces vertically, the special light reflection pattern, which includes a dark central region and a bright field outside, was observed. A critical spot on the curved liquid surface was found, and the dark field distribution is related to both the width of incidence beam and this critical spot. In our experiment, the different dark field distribution patterns were recorded when the width of the incidence beam changed. The liquid surface tension, contact angle, and the liquid surface shape were measured simultaneously. The proposed method is a new effective tool for present wetting characterization methods.