Needham D, Haydon D A
Biophys J. 1983 Mar;41(3):251-7. doi: 10.1016/S0006-3495(83)84435-X.
A method is described for the accurate measurement of the interfacial tension of lipid bilayer membranes containing little or no solvent. The tensions were obtained from the interfacial tensions of the equilibrium film-forming solution in the Plateau-Gibbs border, measured by conventional techniques, and the contact angle between the border and the bilayer. The contact angles in these systems are large (greater than 10 degrees) and were estimated by a new method that involved the injection of small known volumes of lipid solution into the bilayer so as to form a lens. Results have been obtained for monoolein-triolein, monoolein-squalene, and monoolein-squalene-decane systems. Half bilayer tensions in these systems were up to approximately 1 mN m-1 less than the single interface tensions. Although bilayer tension tended to increase with bilayer thickness, the interdependence of these quantities varied with the alkane solvents present. In the monoolein-squalene-decane systems, small concentrations of decane have a larger effect on tension than on thickness. Free energies of formation of the near-solventless bilayers were much greater than estimated from the simple application of Lifshitz theory.
描述了一种用于精确测量几乎不含或不含溶剂的脂质双层膜界面张力的方法。这些张力是通过常规技术测量的普拉托 - 吉布斯边界中平衡成膜溶液的界面张力以及边界与双层之间的接触角获得的。这些系统中的接触角很大（大于10度），并通过一种新方法进行估计，该方法涉及将小体积已知脂质溶液注入双层中以形成透镜。已获得单油酸甘油酯 - 三油酸甘油酯、单油酸甘油酯 - 角鲨烯和单油酸甘油酯 - 角鲨烯 - 癸烷系统的结果。这些系统中的半双层张力比单界面张力低约1 mN m-1。尽管双层张力倾向于随双层厚度增加，但这些量之间的相互依存关系随存在的烷烃溶剂而变化。在单油酸甘油酯 - 角鲨烯 - 癸烷系统中，低浓度的癸烷对张力的影响比对厚度的影响更大。近无溶剂双层的形成自由能远大于从简单应用 Lifshitz 理论估计的值。
