标题： 中子反射率研究超润湿和非超润湿三硅氧烷表面活性剂 显示英文标题

标题： Neutron reflectometry on superspreading and non-superspreading trisiloxane surfactants

摘要： 某些三硅氧烷表面活性剂具有能够超铺展的显著特性：少量的水能够迅速润湿大面积的疏水表面。 这些表面活性剂的分子特性，决定这一技术相关的效应，目前仍在讨论中。 为了更深入地理解，需要在分子尺度上研究表面活性剂在铺展过程中的行为。 在此，我们展示了对两种化学结构相似的三硅氧烷表面活性剂的中子反射分析，其中只有一种表现出超铺展特性。 我们提出了一种方法，用于确定在固-液界面处铺展表面活性剂膜中吸附表面活性剂层的组成，考虑了中子束在厚度范围为几十到几百微米的薄膜中的衰减背向反射贡献。 在自洽分析反射曲线中，关于固/液界面体积分数分布的差异与基于热力学的铺展行为差异的简单解释是一致的。 显示英文摘要

摘要： Certain trisiloxane surfactants have the remarkable property of being able to superspread: Small volumes of water rapidly wet large areas of hydrophobic surfaces. The molecular properties of the surfactants which govern this technologically relevant effect are still under debate. To gain a deeper understanding, the surfactant behaviour during the spreading process needs to be studied at molecular length scales. Here, we present neutron reflectivity analyses of two trisiloxane surfactants of similar chemical structure, of which only one exhibits superspreading properties. We present an approach to determining the composition of the adsorbed surfactant layer in spread surfactant films at the solid-liquid interface, accounting for contributions from attenuated back-reflections of the neutron beam in films with thicknesses in the range of several tens to hundreds of micrometers. Differences between superspreading and non-superspreading surfactants with regard to their volume fraction profiles at the solid/liquid interface obtained in the self-consistent analysis of the reflectivity curves are in agreement with a simple explanation of the difference in spreading behaviour based on thermodynamics.