Detection and Measurement of Microaggregation in Binary Mixtures of Esters and of Phospholipid Dispersions
Detection and Measurement of Microaggregation in Binary Mixtures of Esters and of Phospholipid Dispersions
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酯和磷脂分散体二元混合物中微聚集的检测和测量
DOI：
10.1021/j100020a082
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
D. A. Cates
中科院分区：
文献类型：
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作者：
R. G. Snyder;H. L. Strauss;D. A. Cates
早期开发的用于研究正构烷烃混合物中自发分层的红外方法被用于测量结晶状态下的烷基甲基酯的二元混合物中的微聚集，以及由两种酰基链长度不同的对称磷脂组成的磷脂双层。所涉及的酰基链的长度在18-24个碳的范围内。在室温下发生自发分层的熔融淬火酯mixtures，其中，除了一种情况下，在正交相。在特殊情况下，分层发生在六方相。分层的动力学类似于先前对正构烷烃混合物观察到的动力学。观察到磷脂混合物中的分层，但是，在我们的测量条件下，未发现其具有时间依赖性。我们的结果与文献中描述的具有12-16个碳的烷基链的磷脂的相行为基本一致。Thesensitivity的红外方法，小域使我们能够测量聚集在凝胶状态的磷脂混合物的链长差异2个碳，mixturepreviously被认为是随机混合的固溶体。
An infraredmethod developed earlier for the study of spontaneous demixing in «-alkane mixtures was used to measure microaggregation in binary mixtures of alkyl methyl esters in the crystalline state and also in phospholipid bilayers consisting of two symmetric phospholipids that differ in the length of their acyl chains. The lengths of the acyl chains involved are in the range of 18—24 carbons. Spontaneous demixing at room temperature occurred for the melt-quenched ester mixtureswhich, except for one case, were in the orthorhombic phase. In the exceptional case, the demixing occurred in the hexagonal phase. Thekinetics of demixing are similar to those observed earlier for «-alkane mixtures. Demixing in the phospholipid mixtures was observed, but, under the conditions of our measurements, was not found to be time dependent. Our results are generally in keeping with the phase behavior reportedin the literature for phospholipids with alkyl chains having 12—16 carbons. Thesensitivity of the infrared method to small domains allowed us to measure aggregation in gel-state phospholipid mixtures with chain-lengthdifferences of 2 carbons, mixturespreviously considered to be randomly-mixed solid solutions.