选择天然高分子壳聚糖(CS)衍生物羧甲基壳聚糖(CMC)与辛醛(OA)制备一种两亲性的非离子表面活性剂──羧甲基壳聚糖接枝辛醛(CMC-g-OA)。以十二烷基硫酸钠(SDS)、蓖麻油酸钠(SR)和CMC-g-OA作为复合表面活性剂,在室温下制备一种新型环境友好的阿维菌素(Ave)微乳剂(ME)。该微乳剂具有清澈透明的外观,适宜的pH值,良好的耐硬水、低温和热储稳定性,用高效液相色谱测定的最高有效成分含量为1.855%。对Ave微乳剂的形态结构进行表征的结果显示,不同Ave含量的微乳剂100倍稀释液的粒径尺寸在90~160 nm,粒径分布指数(PDI)小于0.3。表面电荷的Zeta电位值均为负值,表明亲水性的羧基负离子分布在微乳粒子的表面,形成了O/W的微乳液。在微乳剂的稀释液中加入商业铺展剂Silwet408,随其含量增加,在不同作物叶片上的接触角呈减小趋势。
Based on a nature polysaccharide chitosan derivative-carboxymethyl chitosan(CMC) and a natural octyl aldehyde(OA),a water dissolvable non-ionic surface active agent-octyl aldehyde-grafted-carboxymethyl chitosan(CMC-g-OA) was synthesized.In addition,a new environment-friendly avermectin microemulsion formulation was developed by using sodium dodecyl sulfate(SDS),sodium ricinoleate(RN) and CMC-g-OA as a compound surface active agent at room temperature.The microemulsion formulation has some advantages,such as transparent appearance,suitable pH,thermostability,better resistance for hard water and low temperature.And the efficient percentage of Ave in microemulsion measured by HPLC is up to 1.855%.The particle size,size distribution,contact angle for various plant leaves were characterized and examined.The results showed that the particle size of the Ave microemulsion diluted by 100 times was between 90 nm and 160 nm and the particle size distribution index was below 0.300.The zeta potential was below zero,indicating that the anoin carboxyl groups were distributed on the surface of the microemulsion particle and formed a O/W microemulsion.The contact angle of Ave microemulsion for various plant leaves gradually deceased with an increase of the content of the spreader Silwet 408 in the microemulsion formulation.