Pentadecanoic acid pressure-area isotherms

Figure 2. Surface pressure-area isotherm for fatty acids and phospholipids. The inset shows the behavior at large molecular areas. Four one-phase regions are identified gaseous, liquid expanded, liquid condensed, and solid. This isotherm is typical of pentadecanoic acid at room temperature. For a higher-molecular weight acid, such as octadecanoic acid, there is no LE region at room temperature the isotherm does not rise steeply until an area of about 25 A. ...

Figure 8-8 (A) The Langmuir-Adam film balance. Tension on the moveable barrier is recorded for different areas of the surface between the barriers. This gives the surface pressure jt, which is the difference between the surface tension (y0) of a clean aqueous surface and that of a spread monolayer (y) K = ya-y. Courtesy of Jones and Chapman.81 (B) Surface pressure (7t)-area per molecule isotherm for a typical fatty acid (e.g., pentadecanoic acid C14H29C02H) at the aqueous-air interface. From Knobler.81a...

B) Surface pressure (re)-area per molecule isotherm for a typical fatty acid (e.g., pentadecanoic acid Cj4Fl29C02Ft) at the aqueous-air interface. From Knobler. ... 

Fig. 8.19 Surface pressure against area isotherms for pentadecanoic acid monolayers on acidified water (pH = 2). (From reference Gl, with permission.)...

Figure 3.79. Surface pressure jt) versus molecular area isotherm of pentadecanoic (C15) acid L monolayer on pure water at alxrut 30°C. Various features of isotherm can be identified with different structural phases. Adapted, by permission, from D. K. Schwartz, Surf. Sci. Reports 27, 241 (1997), p. 248, Fig. 1. Copyright 1997 Elsevier Science B.V.

---