【作者】 胡云峰；

【导师】 于才渊；

【作者基本信息】 大连理工大学 ， 化学工程， 2008， 硕士

【摘要】 避蚊胺是一种高效、广谱的蚊虫驱避剂,问世已经超过50年,依然是世界范围内应用最广泛的驱避剂。避蚊胺具有驱避效果好、作用毒性小、应用范围广的优点。但是也存在诸如作用时间短、皮肤施用量大、透皮吸收较多等问题,从而可能导致皮炎及心血管疾病等副反应等问题。利用微胶囊技术将避蚊胺微胶囊化后,既不影响避蚊胺的驱蚊效果,利用微胶囊控制释放的特点还可以起到延长驱避作用时间、减少透皮吸收等诸多好处。本文对复合凝聚法制备避蚊胺微胶囊进行了研究,研究内容主要包括:复合凝聚法各因素对微胶囊产品的影响、考察了微胶囊的缓释性能。本文首先通过单因素实验考察了芯壁材比例、反应时间、反应温度、搅拌转速、乳化剂含量和乳化剂HLB值对微胶囊产品的影响,找到合适的参数操作范围。在单因素实验的基础上,设计了正交试验,通过对正交试验结果的分析,找到了最佳的工艺条件:芯壁材比例1:1、反应时间40min、反应温度40℃、搅拌转速2000r/min、乳化剂含量1%、乳化剂HLB值12。在此条件下微胶囊的包埋率达到了75.3%。本文对微胶囊产品进行了表征,测定了微胶囊缓释性能曲线,经过计算,在24h的缓释时间内,平均缓释速率为12.44μg/cm~2·h,远小于避蚊胺在常温下的蒸发速率22.6±2.183μg/cm~2·h。本实验比较了交联固化剂甲醛的用量对缓释性能的影响,实验发现:通过控制交联固化剂甲醛的用量可以起到控制微胶囊产品缓释速率的作用。由实验结果来看,通过复合凝聚法将避蚊胺微胶囊化是可行的。缓释实验证明了微胶囊具有的缓释效果,这对延长驱避作用时间、减少透皮吸收是至关重要的。复合凝聚法过程简单、原料便宜、易于实现大规模生产,无论是对军、民都有很强的现实意义。更多还原

【Abstract】 DEET is a sort of effective, broad-spectrum insect repellent, which was invented over 50 years.DEET is still used extensively against both human and animal pests. DEET has many advantages, such as broad-spectrum and low toxicity, but the longevity of DEET action is short and the quantity of DEET absorption through the skin is much, which potentially could increase the risk of dermatitis or DEET-induced toxicity. Microencapsulation technique can prolong the action longevity of DEET and reduce quantity of DEET absorption through the skin, with no influence on it effect.This paper studies the microencapsulation of DEET by complex coacervation.The main content of this study is the influence of several operational parameters of complex coacervation, and investigation control release performance of microcapsules.Several operational parameters, such as the composition ratio between coating material and core material, the preparation temperature, the preparation time, the mixer rotation speed, the HLB value of emulsion and the content of emulsion, are investigated in the single factor analysis. Furthermore, the optimum condition of complex coacervation is achieved by orthogonal experiment, including the composition ratio between coating material and core materiall is 1:1, the preparation temperature is 40℃, the preparation time is 40min, the mixer rotation speed is 2000r/min, the HLB value of emulsion is 12 and the content of emulsion is l%.The microencapsulation efficiency reaches 75.3%.Finally, the microencapsulation product has been characterized, the control release performance of the microcapsule shows that the average control release velocity is 12.44μg/cm~2·h in 24 hours,much less than the normal evaporation velocity of DEET 22.6±2.183μg/cm~2·h.This study also compares the influence of metamorphic reagent formaldehyde,the results show that the content of metamorphic reagent formaldehyde affects control release velocity, the control release of microcapsules can be controlled by formaldehyde dosage.The results show that it is feasible to prolong the action time and reduce quantity of DEET absorption by complex coacervation. The process of complex coacervation is simple; material is cheap.It shows a great prospect in the industrial application.更多还原