鱼藤酮-壳聚糖接枝物农药纳米粒子水分散制剂研究

Rotenone/chitosan graft copolymer nanoparticle aqueous dispersion pesticide formulation

通过全天然产物蓖麻油酸酐(RAN)与羧甲基壳聚糖(CMC)的酰化反应,合成了羧甲基壳聚糖接技蓖麻油酸(CMC-g-RA)共聚物。探讨了原料的相对分子质量、RAN与CMC分子上氨基的物质的量之比、反应温度和溶剂等因素对产物取代度的影响。以CMC-g-RA为载体,通过在中性水中自组装大分子胶束的增溶作用,与植物源农药鱼藤酮(Rot)一起制备了一种新型的农药纳米粒子水分散剂。对其粒径、粒径分布、表面电荷、形态结构和Rot的负载率等物理性能进行了表征,探讨了CMC-g-RA和Rot溶液的浓度对纳米粒子各相关性能的影响。结果表明:所形成的纳米粒子干燥后外观形态呈密实光滑的球状,粒径在200～500 nm之间,具有较窄的粒径分布,表面带负电荷;该纳米粒子的Zeta电位值随CMC-g-RA和Rot质量浓度的升高而增大,在-40～-70 mV之间;Rot的负载率在20%～68%范围内。研究表明,改变Rot和CMC-g-RA溶液的质量浓度配比,可调节纳米粒子的物理性能;控制农药的负载率,有助于调控该新型制剂速效与缓释之间的关系。

Carboxymethyl chitosan grafting ricinolic acid copolymer（CMC-g-RA） was prepared by the acylation reaction of ricinolic acid anhydride（RAN） and carboxymethyl chitosan（CMC）.The influence of factors such as molecular mass,mole ratio of anhydride/amino,reaction temperature and solvent on substituting degree of CMC-g-RA was investigated.Rot and CMC-g-RA,as a botanical pesticide and a carrier,were used to prepare a novel nanoparticle aqueous dispersion by dissolving Rot in the micelle formed from macromolecular chain self-assembly.Physics properties of the nanoparticle aqueous dispersion,such as particle size and dispersion,surface charge and loading efficiency as well as morphology structure,were characterized.Influence of solution concentration for CMC-g-RA and Rot on above properties was discussed.It is showed that the nanoparticles prepared from CMC-g-RA and Rot have smooth and close rotundity shape,particle sizes of 200-500 nm,narrow particle size distribution and negative surface charge.Zeta potential value of the nanoparticles are from-40 to-70 mV and increased with an increase in the concentrations of Rot and CMC-g-RA.The loading efficiency for nanoparticles are of a range of 20%-68%.In conclusion physics properties were controlled by matching concentration of CMC-g-RA and Rot,and loading efficiency could be regulated effectively,which the balance between fast effect and controlled release of the pesticide formulation can be tailored consequently.