2. Monopolar surfaces in water

is of order of a few dynes/cm.

Surface energies of most of the surfaces other than metals are of order of 50 dynes/cm.

There will be an AB repulsion between the surfaces if

For water, this is termed as hydration pressure and is given by

This condition is readily satisfied by a large number of materials in water. There is repulsion but this does not lead to molecular solution as in the case of sugar.

The concept of negative interfacial tension is closely related to hydration pressure.

Thus, there is a high negative interfacial tension. This causes repulsion against the liquid.