Department of Applied and Engineering Chemistry, Faculty of Technology, Bul. Cara Lazara 1, 21000 Novi Sad, Serbia.
J Colloid Interface Sci. 2010 Feb 15;342(2):333-9. doi: 10.1016/j.jcis.2009.10.077. Epub 2009 Nov 3.
The aim of this work was to investigate the influence of interactions between 1.00%w/w hydroxypropylmethyl cellulose (HPMC) and the anionic surfactant sodium dodecylsulfate (SDS) on the properties of 20%w/w sunflower oil/water emulsion and the corresponding microcapsules obtained by spray drying technique. On the basis of the viscosity and rheological measurements, particle size and particle size distribution, and stability assessment, it was concluded that the emulsion characteristics depend strongly on the interaction mechanism. Significant increase in viscosity and non-Newtonian thixotropic behavior was observed in the SDS concentration range from 0.15 to 1.00%w/v, corresponding to HPMC-SDS interactions in the continuous phase. In the interaction region, a three-dimensional network is formed in the continuous phase by intermolecular binding of SDS molecules to the adjacent HPMC chains, which contributes to increase in the viscosity and thixotropic properties. The mean diameter of emulsion particles, d(vs), decreases with increase in SDS concentration, but emulsion stability depends on the adsorption layer structure, i.e. HPMC-SDS interactions. The HPMC/SDS complex adsorbed at the o/w interface makes the layer more compact, enhancing thus emulsion stability. Microcapsules, obtained in the form of powder by spray drying of emulsions, have good redispersibility in water, but their stability changes depending on the HPMC-SDS interaction mechanism, i.e., the HPMC/SDS complex forms a more compact layer that is resistant to breaking during the drying process. The highest encapsulation efficiency was found in the interaction region.
本工作旨在研究 1.00%w/w 羟丙基甲基纤维素（HPMC）与阴离子表面活性剂十二烷基硫酸钠（SDS）之间的相互作用对 20%w/w 葵花籽油/水乳液及其通过喷雾干燥技术获得的相应微胶囊的性质的影响。基于粘度和流变测量、粒径和粒径分布以及稳定性评估，得出结论乳液特性强烈依赖于相互作用机制。在 SDS 浓度范围从 0.15 到 1.00%w/v 时，观察到粘度和非牛顿触变性显著增加，这对应于连续相中 HPMC-SDS 相互作用。在相互作用区域中，通过 SDS 分子与相邻 HPMC 链之间的分子间键合，在连续相中形成三维网络，这有助于增加粘度和触变性能。乳液颗粒的平均直径 d(vs)随 SDS 浓度的增加而减小，但乳液稳定性取决于吸附层结构，即 HPMC-SDS 相互作用。在 o/w 界面处吸附的 HPMC/SDS 复合物使层更致密，从而增强乳液稳定性。通过乳液喷雾干燥获得的微胶囊呈粉末状，在水中具有良好的再分散性，但它们的稳定性取决于 HPMC-SDS 相互作用机制，即 HPMC/SDS 复合物形成更致密的层，在干燥过程中不易破裂。在相互作用区域中发现了最高的包封效率。
