II : JavaScript calculation of Surface Tension by Sessile Drop
1. Take a photo of a sessile drop. Any liquid is available, if you know its density.
2. Measure r, z, and θ of any point on the liquid surface.
3. Input the parameters and push to calculate.
< Density of the liquid > ρ=
< Arbitrary point P on the surface of sessile drop > r=
z=
θ=
Surface tension; γl= *.**
[mN/m] or [mJ/m2] report of numerical calculation
4. Tips
If you measure the parameters for other surface points to take average,
you may be able to increase the accuracy.
γl ≒ 70 [mN/s] for water.
Surface tension is sensitive to impurities.
For example, very few alcohol decreases it drastically[2].
[1] K.Takahashi,et.al.,"A non-iterative method to evaluate surface tension
and contact angle simultaneously by a sessile drop in gravity
using universal figures", Quarterly Journal of The Japan Welding Society,
v.39 (2021), pp.32-38.( https://doi.org/10.2207/qjjws.39.32 )
above paper is translated in English;
Welding International, v.35, Issue4-6, pp.230-239, 2021
( https://doi.org/10.1080/09507116.2021.1980294 )
[2] G.Vazquez, E.Alvarez, and J.M.Navaza, "Surface Tension of Alcohol + Water
from 20 to 50℃", J. Chem. Eng. Data, v.40 (1995), pp611-614 Kunio TAKAHASHI Lab. in Tokyo Tech.
