Laboratoire Léon Brillouin, CEA-CNRS, CEA Saclay, 91191 Gif sur Yvette Cedex, France.
J Colloid Interface Sci. 2011 Oct 15;362(2):397-405. doi: 10.1016/j.jcis.2011.06.080. Epub 2011 Jul 13.
The ethanolamine salt of 12-hydroxy stearic acid is known to form tubes having a temperature tunable diameter. Here, we study the behavior of those tubes at the air/water interface by using Neutron Reflectivity. We observed that tubes indeed adsorbed at this interface below a fatty acid monolayer and exhibit the same temperature behavior as in bulk. There is however a peculiar behavior at around 50 °C for which the increase of the diameter of the tubes at the interface yields an unfolding of those tubes into a multilamellar layer. Upon further heating, the tubes re-fold and their diameter re-decreases after which they melt into micelles as observed in the bulk. All structural transitions at the interface are nevertheless reversible. This provides to the system a high interest for its interfacial properties because the structure at the air/water interface can be tuned easily by the temperature.
已知 12-羟基硬脂酸的乙醇胺盐能够形成具有温度可调直径的管状结构。在这里，我们通过使用中子反射率来研究这些管状结构在空气/水界面的行为。我们观察到，这些管状结构确实在脂肪酸单层以下的界面处被吸附，并表现出与本体相同的温度行为。然而，在大约 50°C 时存在一种特殊的行为，此时管状结构在界面处的直径增加会导致管状结构展开成多层层状结构。进一步加热后，管状结构重新折叠，直径再次减小，然后像在本体中观察到的那样，它们熔化成胶束。然而，界面处的所有结构转变都是可逆的。这使得该体系在界面性质方面具有很高的研究价值，因为通过温度可以很容易地调节空气/水界面处的结构。
