Grünewald E Wouter, Dalgliesh Robert M, Parnell Steven R, Bouwman Wim G, Smith Gregory N
Reactor Institute, Technische Universiteit Delft, Mekelweg 15, 2629 JB Delft, The Netherlands.
ISIS Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom.
Langmuir. 2025 Jun 3;41(21):12883-12889. doi: 10.1021/acs.langmuir.4c05364. Epub 2025 May 19.
Since macroemulsions are only kinetically stable, characterizing their behavior as they change over time is relevant to their application. Time-of-flight spin-echo small-angle neutron scattering (SESANS) enables time-resolved measurement of the bulk evolution of concentrated, opaque emulsions without perturbing the system. Here, we present time-of-flight SESANS measurements of an -decane-in-DMSO emulsion stabilized by Pluronic P-123, where changes in the system as it ripened were resolved. The radius of emulsion droplets were shown to grow over time with a rate of 25 μm h, suggesting that Ostwald ripening is the dominant aging process. Furthermore, SANS measurements revealed the presence of a stable population of swollen surfactant micelles, providing an additional mechanism for mass transfer between particles. Since time-of-flight SESANS can be used to obtain information about particle sizes, ripening rates, and associated processes, it is uniquely suited for studying the behavior of dense colloidal systems over time.
由于宏观乳液仅具有动力学稳定性，表征其随时间的变化行为与其应用相关。飞行时间自旋回波小角中子散射（SESANS）能够在不干扰系统的情况下对浓缩、不透明乳液的整体演化进行时间分辨测量。在此，我们展示了由普朗尼克P - 123稳定的二甲基亚砜中癸烷乳液的飞行时间SESANS测量结果，其中解析了系统成熟过程中的变化。乳液滴的半径显示出随时间以25μm/h的速率增长，这表明奥斯特瓦尔德熟化是主要的老化过程。此外，小角中子散射测量揭示了存在稳定的肿胀表面活性剂胶束群体，为颗粒间的质量传递提供了另一种机制。由于飞行时间SESANS可用于获取有关颗粒大小、熟化速率及相关过程的信息，它特别适合研究致密胶体系统随时间的行为。
