中文摘要：

利用表面压力-平均分子面积（π-A）曲线的关系,分别研究了在水/空气界面上形成的磷酯酰乙醇胺（PE）与硬脂酸（SA）和十八醇（OD）二元混合体系的热力学特性.根据对弹性模量（CS-1）、过量分子面积（Aex）以及表面过量吉布斯自由能（ΔGex）等热力学参数的数据计算,定量分析了混合单层膜分子之间的相互作用.实验结果表明,PE/SA和PE/OD单层膜两种组分之间摩尔比对其热力学参数有影响.热力学分析表明,在XSA=0.2,0.8和XOD=0.8处,PE/SA和PE/OD二元混合体系的热力学参数[过量分子面积（Aex）和表面过量吉布斯自由能（ΔGex）]相对理想状态均表现为负偏差作用,说明分子之间的作用为引力作用.相反,PE/OD二元体系在XOD=0.2,0.4,0.6处,表现为正偏差作用,这说明分子之间的作用为斥力作用.AFM观测为PE/SA和PE/OD单层膜热力学特性的理论分析提供了有力的支持.

英文摘要：

Thermodynamic characteristics of binary mixtures of phosphatidylethanolamine（PE） with stearic acid（SA）,and octadecanol（OD） formed at the air/water were investigated in terms of surface pressure（π）-area（A） relation.On the basis of the data,the thermodynamic parameters of compression modulus（C-1S）,excess mean area per molecule（Aex）,and surface excess Gibbs energy（ΔGex） were calculated.We can quantitatively analyze the molecular interactions in the mixed monolayers.The experimental results showed that the various molar ratios of the two components,PE and SA,PE and OD,influenced thermodynamic parameters.The thermodynamic analysis indicated that the thermodynamic parameters[excess molecular area（Aex）,surface excess Gibbs energy（ΔGex）] of PE/SA and PE/OD were obtained maximum negative deviation from the ideal behavior at XSA=0.2,0.8 and XOD=0.2,suggesting an attractive interaction between molecules.The other way round,the molar ratios of OD at XOD=0.2,0.4,0.6,were found to be conspicuously maximum positive,suggesting an intermolecular repulsion.The AFM images of mixed PE/SA and PE/OD monolayers are in favor of the theoretic analysis of the thermodynamic characteristics.