壳聚糖空心微胶囊的制备及其负载农药的特性研究

发布时间：2018-02-06 04:21

本文关键词： 壳聚糖微胶囊模板法农药机理　出处：《西南科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：近年来,农药的滥用已经成为一个严重的环境问题。其引发的农药残留和环境污染现象已经威胁到人类的健康。因此,在保证农药药效的前提下,有必要进行农药微量使用的研究,以严格控制其使用量,而将农药微胶囊化是较为理想的手段之一。农药微胶囊化是使用某种壁材将农药的有效成分包裹起来,使其能通过渗透扩散的方法慢慢释放。对于微胶囊囊壁材料的选取而言,具有生物相容性和可生物降解的天然高分子材料备受青睐。本文采用壳聚糖作为囊壁材料,以吡虫啉为模型药物进行农药微胶囊化。通过对吡虫啉微胶囊化得可行性和其载药机理的探究发现,由于壳聚糖特殊的分子结构,其空心微胶囊对吡虫啉的负载存在着氢键作用。同时,该载药微胶囊在甲醇中的释药行为表明了其存在着突释,对于农药微胶囊而言,一定量的农药突释有助于其发挥药效。后期的释药率趋于稳定并有一部分药物由于负载于内部而无法再短时间释出说明了交联壳聚糖的释药机制由药物扩散与载体的降解组成。此外,本文还对壳聚糖空心微胶囊的制备过程进行了探究,研究发现,模板磺化聚苯乙烯的磺化度随着磺化时间的增大而增大,但当磺化度增大到一定时,磺化聚苯乙烯微球的亲水性会减小。而核-壳结构的磺化聚苯乙烯-壳聚糖微胶囊在用四氢呋喃溶去模板时,其中的—SO_3~-会因与—NH_3~+的紧密结合而留在空心微胶囊中。本研究通过探究交联壳聚糖微胶囊对吡虫啉的负载的可行性,揭示了其中的载药机理,为交联壳聚糖空心微胶囊在载药领域的应用提供理论依据。
[Abstract]:In recent years, the abuse of pesticides has become a serious environmental problem. Pesticide residues and environmental pollution caused by the phenomenon have threatened human health. Therefore, under the premise of ensuring the efficacy of pesticides. It is necessary to study the micro-use of pesticides in order to strictly control the amount of pesticide, and the pesticide microencapsulation is one of the more ideal means. Pesticide microencapsulation is the use of some wall materials to wrap the active components of pesticides. It can be released slowly by osmotic diffusion. For the selection of microcapsule wall materials. Natural polymer materials with biocompatibility and biodegradability are very popular. In this paper, chitosan is used as the wall material. Imidacloprid was used as model drug for pesticide microencapsulation. The feasibility of imidacloprid microencapsulation and the mechanism of imidacloprid microencapsulation were investigated. It was found that due to the special molecular structure of chitosan. At the same time, the release behavior of the microcapsule in methanol showed that there was a sudden release, for pesticide microcapsules. The drug release rate tends to be stable in the later stage and some of the drugs can not be released in a short time due to the internal loading which indicates that the drug release mechanism of cross-linked chitosan is spread and loaded by drugs. The degradation composition of the body. The preparation process of chitosan hollow microcapsules was also studied. It was found that the sulfonation degree of template sulfonated polystyrene increased with the increase of sulfonation time, but when the sulfonation degree increased to a certain extent. The hydrophilicity of sulfonated polystyrene microspheres is reduced, while the core shell structure sulfonated polystyrene chitosan microcapsules are dissolved in tetrahydrofuran to remove the template. In this study, the feasibility of loading imidacloprid by cross-linked chitosan microcapsules was investigated. The mechanism of drug loading is revealed, which provides a theoretical basis for the application of cross-linked chitosan hollow microcapsules in the field of drug loading.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O636.1;TQ450.4

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