Department of Chemical Engineering, University of Melbourne, Parkville, Victoria 3010, Australia.
Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092 Zurich, Switzerland.
ACS Appl Mater Interfaces. 2020 Oct 21;12(42):48084-48092. doi: 10.1021/acsami.0c11781. Epub 2020 Oct 7.
The time-dependent behavior of surface-active adsorption layers at the oil/water interface can dictate emulsion behavior at both the micro- and macroscale. In addition, self-healing behavior of the adsorption layer may benefit emulsion stability subject to large deformation under processing or during final application. We explore the behavior of chitosan, a known hydrophilic emulsifier, which forms nanoparticle aggregates when the concentration of acetate buffer exceeds 0.3 M. We observe a Pickering adsorption layer building and strain-dependent behavior of the chitosan at the medium chain triglyceride oil/water interface. We compare this to the behavior of identical chitosan layers coated on oil droplets atomic force microscopy colloidal probe compression in both linear and oscillatory compressions. In both interfacial shear rheometry and the capsule compression, a thick, elastic layer with strong time-dependent recovery behavior is observed, suggesting that the layer has some self-healing capabilities.
在油/水界面处，表面活性吸附层的时变行为可以控制乳液在微观和宏观尺度下的行为。此外，在加工或最终应用过程中受到大变形时，吸附层的自修复行为可能有利于乳液稳定性。我们研究了壳聚糖的行为，壳聚糖是一种已知的亲水性乳化剂，当醋酸盐缓冲液的浓度超过 0.3 M 时，它会形成纳米颗粒聚集体。我们观察到中链甘油三酯油/水界面处壳聚糖的 Pickering 吸附层的形成和应变依赖性。我们将这与涂有相同壳聚糖层的油滴的行为进行了比较，通过原子力显微镜胶体探针在线性和振荡压缩下进行了压缩。在界面剪切流变仪和胶囊压缩中，都观察到了具有强时变恢复行为的厚弹性层，表明该层具有一定的自修复能力。
