不同乳化过程对高效氯氰菊酯纳米乳液物理稳定性的影响

The effect of different emulsifying process on the physical stability of deta-cypermethrin nanoemulsions

通过分析Turbiscan Lab分散稳定性分析仪扫描图谱,测定液滴平均粒径的变化情况,考察纳米乳液热力学性能,并结合光学显微观察及热贮后外观观察,综合比较4种不同乳化过程制备的高效氯氰菊酯纳米乳液的稳定性。结果表明:纳米乳液A(乳化剂添加在油相中的反相乳化法制备)的背散射光强度发生轻微变化,液滴初始平均粒径最小(168nm),且贮存后变化不大,显微镜观察液滴细微且分布均匀,结晶温度低,热贮后外观均一,稳定性最好;纳米乳液C(乳化剂添加在油相中的直接乳化法制备)的稳定性次之;纳米乳液B(乳化剂添加在水相中的直接乳化法制备)和纳米乳液D(乳化剂添加在水相中的反相乳化法制备)的背散射光强度变化明显,液滴初始平均粒径均较大(大于1 000nm),且贮存后仍有增大趋势,显微镜观察液滴粗大,分布密集,结晶温度较高,热贮后外观不均一,产生乳析,纳米乳液D稳定性最差,接近破乳。

The stability of nanoemulsions prepared by different emulsifying processes was comprehensively compared by analyzing Turbiscan Lab scanning spectrum, measuring variation in average droplets size, examining the thermody- namic performance, the optical micrograph of nanoemulsions and the appearance of nanoemulsions after accelerated test [（54±2）℃, 14 d]. For nanoemulsion A, which was prepared by inversed phase emulsification with adding emulsifier in the oil phase, displayed slight change in backscattered light intensity, smallest initial average droplets size （168 nm） with minor change after the storage, fine droplet distribution by microscopic observation, low crystallization temperature, uni- form appearance after accelerated test, and the best stability. The stability of nanoemulsion C prepared by direction emul- sification with adding emulsifier in the oil phase was followed. For nanoemulsion B （prepared by direction emulsification with adding emulsifier in the aqueous phase） and D （prepared by inversed phase emulsification with adding emulsifier in the aqueous phase）, exhibited more obvious change in the backscattered light intensity, larger initial average droplets size （〉1 000 nm） with an increasing trend after the storage, bulky droplets as well as nonuniform and intensive droplets dis- tribution by microscopic observation, higher crystallization temperature, extremely uneven appearance and displayed crea- ming after accelerated test. Nanoemulsion D had the worst stability, which was closed to the demulsification.