番茄红素与硬脂酸的混合单分子膜  

Mixed Monolayers of Lycopene and Stearic Acid

作　　者：阳建斌[1] 朱谱新[1] 杨红伟[1] 吴大诚[1] 

机构地区：[1]四川大学纺织研究所,四川成都610065

出　　处：《四川大学学报（工程科学版）》2005年第5期93-97,共5页Journal of Sichuan University (Engineering Science Edition)

基　　金：国家自然科学基金资助项目(29974019)

摘　　要：研究了番茄红素与硬脂酸在空气-水界面上形成的超分子复杂体系,了解混合单分子膜的结构、相转变和相容性等。由于番茄红素缺乏极性基团,它在空气-水界面上铺展的π-A曲线中,即使在分子面积达到0.1 nm2时也没有出现固态膜的特征。当番茄红素与硬脂酸混合后,可以得到稳定的单分子膜,但是在较高表面压下会出现相分离现象。在混合膜的崩溃压以上,其π-A曲线出现一个平台区域,随着分子面积进一步降低,表面压升高。因为在较高表面压下,番茄红素分子被挤出混合单分子膜,逐渐以随机形式平躺在硬脂酸单分子膜上而形成多层膜。另一方面,通过加和规则等评价番茄红素和硬脂酸的混合单分子膜性质。混合单分子膜在不同表面压下分子面积的加和原理表明,与理想混合曲线相比,在番茄红素摩尔分数较低时有正偏差,在其较高时有负偏差。同时,计算了混合单分子膜在不同表面压下的混合能和相互作用常数,说明番茄红素与长链脂肪酸在空气-水界面上的相互作用。Lycopene is one of natural carotenoids with high lipophilicity. The isotherm of lycopene at air-water interface did not show characteristics of solid-film even for the molecular area up to 0.1 nm^2, for lack of any polar group in its molecule. After mixed with stearie acid, a kind of stable monolayers could be available, but appeared an unusual phaseseparation phenomenon over 45 mN· m^- 1. For the mixed fi of the surface pressure a plateau region was appeared in the lm, it was isotherrns shown experimentally that above the collapse point and then the surface pressure went up with the decrease of the molecular area. The result was suggested that lycopene molecules were pushed out from the mixed monolayer over a higher surface pressure, gradually forming a multilayer with a pattern that lycopene molecules tended to randomly lle down on the stearic acid monolayer. On the other hand, the characterizations of their mixing behaviour have been assessed by thermodynamics addltivlty rule. The additivity of the molecule area of mixed monolayers at different pressure showed a positive deviation in low mol fraction of lycopene in mixtures, and a negative deviation in high ratio to its ideal valules. The mixing energies and interaction parameters at different surface pressure were calculated.

关 键 词：混合单分子膜 LANGMUIR膜 番茄红素 硬脂酸 

分 类 号：O647.1[理学—物理化学]