壳聚糖/木质素磺酸钠复凝聚法制备生物农药微胶囊

研究了以壳聚糖和木质素磺酸钠为囊材，以阿维菌素为囊芯，采用复凝聚法制备微胶囊。利用正交实验对复凝聚体系形成条件进行了初步筛选，在此基础上，深入研究了影响微胶囊载药量和包封率的各种因素，获得最佳制备工艺条件为：壳聚糖cps1500、壳聚糖浓度0.5%、木质素磺酸钠浓度2%、乳化剂Tween80/Span80配比2、乳化剂用量6 mL、壳芯比6、复凝聚时间15 min、交联剂用量4 mL、交联时间1 h，所得微胶囊的载药量和包封率可达到9.6％和82％。采用FT-IR对微胶囊进行表征的结果表明，囊芯与囊壁之间无化学键合。体外释放动力学研究结果表明，壳聚糖/木质素磺酸钠复凝聚微胶囊对阿维菌素具有一定的控释作用。

Complex coacervation of chitosan and sodium lignosulfonate for microencapsulation of a biopesticide

The biopesticide avermectin was microencapsulated with chitosan and sodium lignosulfonate by a complex coacervation method. The reaction conditions were primarily selected using orthogonal experimental design, and the microencapsulation conditions were further modified by varying the ratio of complex to avermectin, complex coacervation time, and the amount and exposure time of crosslinkers. The optimized microencapsulation conditions were as follows: viscosity of chitosan 1500 cps, concentration of chitosan 0.5%, concentration of sodium lignosulfonate 2%, Tween80/ Span80 ratio 2, amount of emulsifiers 6 mL, ratio of core to shell 6, complex coacervation time 15 min, amount of crosslinker 4 mL, crosslinking time 1 h. The resulting microcapsules had a drug loading and encapsulation efficiency (EE) of 9.6％ and 82％, respectively. The avermectin-containing chitosan/lignosulphate microcapsules were characterized by FTIR, which indicated that there was no chemical interaction between avermectin and the chitosan/lignosulphate complex. The release characteristics of avermectin from the microcapsules obtained under optimized encapsulation conditions were investigated using in-vitro release experiments, which showed that the release rates of avermectin could be effectively controlled.