胆汁酸-表面活性剂在液晶/水界面的相互作用。

Bile acid-surfactant interactions at the liquid crystal/aqueous interface.

机构信息

CREOL, The College of Optics and Photonics, University of Central Florida, Orlando, Florida 32816, USA.

出版信息

Soft Matter. 2014 Jul 14;10(26):4609-14. doi: 10.1039/c4sm00486h.

Abstract

The interaction between bile acids and surfactants at interfaces plays an important role in fat digestion. In this paper, we study the competitive adsorption of cholic acid (CA) at the sodium dodecyl sulfate (SDS)-laden liquid crystal (LC)/aqueous interface formed with cyanobiphenyl (nCB, n = 5-8) and the mixture of 5CB with 4-(4-pentylcyclohexyl)benzonitrile (5PCH). We find that the critical concentration of CA required to displace SDS from the interface linearly decreases from 160 μM to 16 μM by reducing the alkyl chain length of nCB from n = 8 to n = 5 and from 16 μM to 1.5 μM by increasing the 5PCH concentration from 0 wt% to 19 wt% in the 5PCH-5CB binary mixture. Our results clearly demonstrate that the sensitivity of 5PCH-5CB mixtures for monitoring the interaction between CA and SDS at the LC/aqueous interface can be increased by one order of magnitude, compared to 5CB.

摘要

胆汁酸与表面活性剂在界面上的相互作用在脂肪消化中起着重要作用。本文研究了胆酸（CA）在十二烷基硫酸钠（SDS）负载的液晶（LC）/水界面上的竞争吸附作用，该界面是由联苯氰（nCB，n=5-8）和 5CB 与 4-（4-戊基环己基）苯甲腈（5PCH）的混合物形成的。我们发现，通过从 n=8 降低到 n=5，从 160μM 线性降低到 16μM，通过从 0wt%增加到 19wt%，在 5PCH-5CB 二元混合物中增加 5PCH 的浓度，需要取代 SDS 的 CA 的临界浓度从 16μM 线性降低到 1.5μM。我们的结果清楚地表明，与 5CB 相比，5PCH-5CB 混合物对监测 LC/水界面上 CA 和 SDS 之间相互作用的灵敏度可以提高一个数量级。