论文标题
在多分散油中乳液中的亲脂性荧光探针的表面介导的分子转运
Surface-Mediated Molecular Transport of a Lipophilic Fluorescent Probe in Polydisperse Oil-in-Water Emulsions
论文作者
论文摘要
乳液通常充当传递到特定靶标的水不溶的溶质的载体。表面活性剂可以促进乳液中溶质的分子转运，并且通常受到连续相扩散的限制。在这里，我们通过使用亲脂分子转子作为溶质的代理来研究这种传输。使用荧光寿命显微镜，我们跟踪这些分子从连续相位到多分散水中乳液中分散相的传输。我们表明，该传输包括两个时间尺度，它们随液滴的尺寸和表面活性剂浓度差异很大，并且取决于所使用的表面活性剂的类型，可以通过在油水界面上的传输或通过连续相扩散来限制。通过研究荧光团的时间分辨荧光，并伴随分子动力学模拟，我们证明了如何根据探针分子暴露于巨型的环境来解释在宏观尺度上观察到的运输速率。
Emulsions often act as carriers for water-insoluble solutes that are delivered to a specific target. The molecular transport of solutes in emulsions can be facilitated by surfactants and is often limited by diffusion through the continuous phase. We here investigate this transport on a molecular scale by using a lipophilic molecular rotor as a proxy for solutes. Using fluorescence lifetime microscopy we track the transport of these molecules from the continuous phase towards the dispersed phase in polydisperse oil-in-water emulsions. We show that this transport comprises two timescales, which vary significantly with droplet size and surfactant concentration, and, depending on the type of surfactant used, can be limited either by transport across the oil-water interface, or by diffusion through the continuous phase. By studying the time-resolved fluorescence of the fluorophore, accompanied by molecular dynamics simulations, we demonstrate how the rate of transport observed on a macroscopic scale can be explained in terms of the local environment that the probe molecules are exposed to.
