Surface Tension and Interfacial Tension
I was musing, the other day on the designs of two ring tensiometers. One of them is called an interfacial tensiometer and the other simply a tensiometer. The plain tensiometer works only with an upward pull and the interfacial works with both an upward pull as well as a downward push. Before I get to my question a couple of definition might be useful
The phenomenon called surface tension is the property at the surface of a liquid that causes it to behave like a plastic sheet. When you see an insect walking on the surface of a pool or pond, it is because of the surface tension of the water.
The normal example is the surface tension of water exposed to air. At room temperature the surface tension of water is a force around 70 dynes/ per centimeter. At the freezing point of water the surface tension is close to infinite. At the other end of the spectrum; as the temperature approaches boiling, the surface tension of the water moves toward 0.
To measure surface tension, for example the surface tension of water, a platinum ring (circle connected to a vertical stem) is pulled through the surface of the water. The water adheres to the ring for some distance above the surface. When it breaks away the force is measured and converted to surface tension…
To read the entire article go to the CSC Scientific blog by clicking on the link below.
Surface Tension and Interfacial Tension
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