Kinetics of the processes of desorption from fatty acid monolayers

Journal of Lipid Research

David G. Cornwell¹  Richard H. Matthews¹  Gajanan S. Patil¹ 

[1] Department of Physiological Chemistry, The Ohio State University, Columbus, Ohio 43210;

关键词: lauric acid;    myristic acid;    palmitic acid;    palmitoleic acid;    oleic acid;    surface pressure;   

DOI  :  

来源: DOAJ

【 摘 要 】

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 √t. In a subsequent steady-state phase, ln A was linear with t. The initial desorption coefficient for sodium palmitate, Ki, and the steady-state desorption coefficient, Ks, varied directly with surface pressure and subphase pH, and these desorption coefficients also varied with the composition of the subphase buffer. However, the Ks/Ki, ratio was independent of these variables. The diffusion coefficient, D25, for sodium palmitate calculated from desorption coefficient ratios was 4.8 ± 0.6 × 10–6 cm2/sec. This value was in reasonable agreement with D25 for sodium palmitate measured by time-lag diffusion, 3.7 ± 0.6 × 10–6 cm2/sec. D25 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.

【 授权许可】

Unknown