Crystal Comets: A Geometric Model for Sculpting Anisotropic Particles from Emulsions
Crystal Comets: A Geometric Model for Sculpting Anisotropic Particles from Emulsions
复制标题
晶体彗星：从乳液中雕刻各向异性粒子的几何模型
DOI：
10.1021/acs.langmuir.0c02249
复制
发表时间：
2020
期刊：
影响因子：
3.9
通讯作者：
Atherton, Timothy J.
中科院分区：
文献类型：
--
作者：
Giso, Mathew Q.;Zhao, Haoda;Spicer, Patrick T.;Atherton, Timothy J.
微观高纵横比颗粒有许多应用，包括增强活性成分的输送和食品稳定性。在这里，我们开发了一个简单的，可扩展的过程，产生具有连续可控长宽比的粒子。水包油乳化液液滴在表面活性剂的存在下被淬火和结晶，表面活性剂有助于固体油相从液体前驱体中喷射出来。通过调节表面活性剂浓度和淬火深度，调整喷射和结晶速率，在结晶过程中不断从前驱液滴喷射凝固油，从而促进各向异性颗粒的生长。我们使用解析几何模型来预测可接近的形貌，该模型表明结晶过程中的接触角是非恒定的。我们看到晶体长宽比取决于表面活性剂的浓度，这可以解释为结晶过程中最大生长角的变化。
Microscopic high aspect ratio particles have many applications including enhanced delivery of active ingredients and food stability. Here, we develop a simple, scalable process that produces particles with a continuously controllable aspect ratio. Oil-in-water emulsion droplets are quenched and crystallize in the presence of surfactants that facilitate the ejection of the solid oil phase from its liquid precursor. Tuning the ejection and crystallization rates to be comparable, by adjusting the surfactant concentration and quench depth, promotes anisotropic particle growth by continuously ejecting solidified oil from the precursor droplet as the crystallization proceeds. We predict the accessible morphologies using an analytical geometric model that indicates a nonconstant contact angle during the crystallization process. We see that the crystal aspect ratio is dependent on the surfactant concentration, which can be explained as a variation of the maximum growth angle achieved during crystallization.