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首页> 外文期刊>Journal of Microencapsulation: Microcapsules Liposomes Nanoparticles Microcells Microspheres >Synthesis and characterization of polyurethane-urea microcapsules containing galangal essential oil: statistical analysis of encapsulation
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Synthesis and characterization of polyurethane-urea microcapsules containing galangal essential oil: statistical analysis of encapsulation

机译：含高良姜精油的聚氨酯-尿素微胶囊的合成与表征：包封的统计分析

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摘要

Galangal essential oil (GEO) is known to possess antimicrobial activity (e.g. against Staphylococcus aureus). A way to increase oil lifetime in plants is encapsulation in polyurethane-urea (PUU) microcapsules. In this study, PUU microcapsules with GEO were synthesized by interfacial polymerization at oil-water interface in oil-water emulsion. A statistical analysis of the microcapsule size was successfully applied for characterization of the encapsulation process. Using the model of reversible aggregation, it was shown that the process of encapsulation takes place in the conditions of thermodynamic control. The polymerization conditions (agitation rate in the range 2000-10 000 rpm/min) are the key factors that affect the mean microcapsule size of primary capsules formed during encapsulation. Two complementary processes were determined the mean capsule size during a transformation of these primary microcapsules: break-up and coalescence of oil droplets in the oil-in-water emulsion. The agitation rate does not influence the coalescence of the oil droplets, but the threshold value of agitation speed (in this system 4000 rpm/min) does exist and that is what strongly increases break-up of oil droplets. The higher agitation rate resulted in smaller size of microcapsules (mean diameter decreasing from 5.6 to 4.9 μm for primary capsules and from 13.8 to 9.8 μm for secondary capsules) and with a narrower size distribution. The last mode of encapsulation allows the more effective use the shell material for encapsulating of larger amount of oil.
机译：高良姜精油（GEO）具有抗菌活性（例如，针对金黄色葡萄球菌）。延长植物油脂寿命的一种方法是将其封装在聚氨酯-脲（PUU）微胶囊中。本研究通过在油水乳液中油水界面的界面聚合反应，合成了具有GEO的PUU微胶囊。微胶囊尺寸的统计分析已成功地用于表征封装过程。使用可逆聚集模型，表明封装过程在热力学控制条件下发生。聚合条件（搅拌速度在2000-10 000 rpm / min范围内）是影响封装过程中形成的初次胶囊平均微胶囊大小的关键因素。确定了这些主要微胶囊转化过程中的平均胶囊大小，这两个互补过程是：水包油型乳液中油滴的分解和聚结。搅拌速度不影响油滴的聚结，但是确实存在搅拌速度的阈值（在该系统中为4000 rpm / min），这就是大大增加油滴破裂的原因。较高的搅拌速率导致微胶囊的尺寸更小（平均直径从一级胶囊从5.6减小到4.9μm，从二级胶囊从13.8减小到9.8μm）并且尺寸分布更窄。最后的封装方式允许更有效地使用外壳材料来封装大量的油。

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