## surface pressure

https://doi.org/10.1351/goldbook.S06185
The change of @I03088@ caused by addition of a given species to a base solution. When an area of liquid covered with a spread substance is separated from a clean area of surface by a mechanical barrier, the force acting on unit length of the barrier is called the surface pressure, $$\pi$$ or $$\pi _{\text{s}}$$, and is equal to $$\gamma ^{0} - \gamma$$ where $$\gamma ^{0}$$ is the @S06192@ of the @C01099@ and $$\gamma$$ that of the covered surface.
Sources:
Green Book, 2nd ed., p. 63 [Terms] [Book]
PAC, 1972, 31, 49. (Extended chain crystals of linear high polymers) on page 59 [Terms] [Paper]
PAC, 1983, 55, 1251. (Interphases in systems of conducting phases (Provisional)) on page 1264 [Terms] [Paper]