Relation of capillary height to contact angle !!

[thermcool]

I am trying to measure the pore size radius of the polyethylene wick using ethanol as the working fluid. In the method i am trying to determine the maximum capillary height that can be achieved by fluid, from which i can measure the pore radius. Unfortunately i don't know the contact angle for the ethanol with polythylene. Could someone tell wheather the contact angle effect the capillary height or it just effect the time require to achieve the head.

Any ideas relating to the subject question are welcome!! Cheers

 

[Compositepro]

Capillary height is definitely a function of both contact angle and pore size. Contact angle is a function of liquid surface tension and solid surface energy. Since surface energy can vary due to many reasons measurements would be most acurate if a calibration standard of known pore size is used.

 

[nbucska]

The capillary force is VERY dependent on contamination !!!

<nbucska@pcperipherals.com>

 

[mboa]

Hey,
Varying the contact angle definitely affects the distance travelled by the ethanol but does not affect the perpendicular height. The only thing you need to take into account is that in this case, use the perpendicular height as the actual height not the distance travelled by ethanol.
To cut the long story short, why not just drop the wick perpendicularly.

 

[Compositepro]

Contact angle is the angle between a solid surface and the tangent to the liquid-vapor surface at the point of contact between the liquid and solid. It is usually mesured with a microscope that looks at the silhouette of a droplet on a test surface. The instrument is called a contact angle goniometer.