This can be one technique which relies on Young-Laplace equation to calculate the surface tension. However for direct measurement of surface tension experimentally, usually Wilhelmy plate or De-Nouy ring methods are used.

Further methods of surface tension measurement are Pendant drop method and Contact lamella method. May be I didn't understood your question exactly, but in any case you would determine mainly surface tension of solvent (water?) and not of polymer blend.

http://www.fdsc.com/melt.html

http://www.kruss.de/services/education-theory/glossary/pendant-drop/

Subhasish and Georg, Thanks for your answers.

I am sorry for my poor English. I'll try to explain the problem once again.

I have determined the surface tension of polymer blend using pendant drop method. Now i wish to resolve this surface tension into dispersive and polar parts of surface tension. To do so I have measured the contact angle of polymer blend on an apolar surface (PE in this case). What I wanted to ask was if I can use a polymer blend to measure contact angle or not as contact angles are generally measured using pure liquids.

I think this is somewhat tricky. When you say blend, it means it's a perfectly mixed system. The surface tension components - [London dispersion (apolar) and polar]  are usually known for pure system. What may be useful is to separately measure the contact angle/surface tension of the individual component of the blend and resolve it into respective polar and apolar part. And then using mole/mass fraction average, possibly the components of the blend could be obtained. Fowkes (1964) paper (perhaps you already have it) may be useful to understand how to calculate these polar/apolar components.

The pendant drop method is the effective method to measure the interfacial tensions of polymer melts.Basing on the Young-Laplace theory, the interfacial

tensions can be calculated by the size parameters.

for example, this paper can be helpful:

Studies on the selective localization of multi-walled carbon

nanotubes in blends of poly(vinylidene fluoride) and

polycaprolactone(DOI: 10.3144/expresspolymlett.2015.8)

Hi everyone,

I have the same question, I wan to measure the water contact angle of PE plastic bag, however, due to its structure, the surface is not flat enough so how the water contact angle can be measured. Also how other papers measure it. They did not explain the procedure.

Any help would be appreciated.