Patil G S, Matthews R H, Cornwell D G
J Lipid Res. 1973 Jan;14(1):26-31.
The surface area, A, of contracting fatty acid monolayers was measured as a function of time, t, at constant surface pressure. In the initial temporal phase, ln A was linear with radical t. In a subsequent steady-state phase, ln A was linear with t. The initial desorption coefficient for sodium palmitate, K(i), and the steady-state desorption coefficient, K(s), varied directly with surface pressure and subphase pH, and these desorption coefficients also varied with the composition of the subphase buffer. However, the K(s)/K(i) ratio was independent of these variables. The diffusion coefficient, D(25), for sodium palmitate calculated from desorption coefficient ratios was 4.8 +/- 0.6 x 10(-6) cm(2)/sec. This value was in reasonable agreement with D(25) for sodium palmitate measured by time-lag diffusion, 3.7 +/- 0.6 x 10(-6) cm(2)/sec. D(25) values obtained for a series of fatty acids suggested that higher members of the series diffused as small aggregates averaging two to four molecules in size. Kinetic and diffusion data both supported a model for the desorption process described by Ter Minassian-Saraga.
在恒定表面压力下，测量收缩脂肪酸单分子层的表面积A随时间t的变化。在初始阶段，ln A与根号t呈线性关系。在随后的稳态阶段，ln A与t呈线性关系。棕榈酸钠的初始解吸系数K(i)和稳态解吸系数K(s)随表面压力和亚相pH值直接变化，并且这些解吸系数也随亚相缓冲液的组成而变化。然而，K(s)/K(i)比值与这些变量无关。根据解吸系数比值计算出的棕榈酸钠的扩散系数D(25)为4.8±0.6×10⁻⁶ cm²/秒。该值与通过时间滞后扩散测量的棕榈酸钠的D(25)值3.7±0.6×10⁻⁶ cm²/秒合理一致。一系列脂肪酸的D(25)值表明，该系列中较高的成员以平均大小为两到四个分子的小聚集体形式扩散。动力学和扩散数据均支持Ter Minassian - Saraga描述的解吸过程模型。
