【摘要】 气液界面上人工铺展的脂类单分子层(LB膜)作为生物膜研究的一种模型正越来越引起人们的重视.我们利用LB膜技术可以严格地控制膜组份及压力等参数的特点,并与扫描电镜形貌观察相结合,对DMPE/Cholesterol二元混合脂类单分子层的结构性质(特别是相行为)进行了研究.各种不同比例混合的DMPE/Cholesterol单分子层的压力(π)—面积(A)等温曲线由实验获得.通过对所获得的π—A曲线族的解析函数:1)压缩角(?)—分子平均密度(ρ)曲线,2)分子平均面积(A)—组分(X)曲线的分析,得到了DMPE/Cholesterol的压力—组分相图.由相图中可分析出二维混合脂类单分子层的液—液二级相变(伴随“气态”分子取向的有序化),液→固一级相变(伴随gauche—trans的转变),及固→固二级相变(伴随gel态分子取向的重排).相图分析的结果已为扫描电镜的观察所证实.更多还原

【Abstract】 Monolayers at the air/water interface are becoming ineresingly important for its application in the field of biomembrane inverstigation. DMPE/Cholesterol binary-mixture monolayers were studied by film balance and scanning electron microscopy. Pressure-Composition phase diagram was established by anlyzing the following functions which obtained from isotherms: 1) The variation of the compressive angle, ?, as a function of lateral density ρ. 2) The molecular area as a function of composition. The phase translation points of liqid to liqid, liqid to crystal and crystal to crystal can be obtained from the phase diagram. The phase diagram compared with the electron micrographs which showed distinguishable domain patterns in vary phases.更多还原