Oil-in-water nanoemulsions for pesticide formulations.
A two-step process for formation of nanoemulsions in the system water/poly(oxyethylene) nonionic surfactant/methyl decanoate at 25 degrees C is described. First, all the components were mixed at a certain composition to prepare a microemulsion concentrate, which was rapidly subjected into a large dilution into water to generate an emulsion. Bluish transparent oil-in-water (O/W) nanoemulsions were formed only when the concentrate was located in the bicontinuous microemulsion (BC) or oil-in-water microemulsion (Wm) region. The existence of an optimum oil-to-surfactant ratio (R(os)) in the BC or Wm region indicates that both the phase behavior and the composition of the concentrate are important factors in nanoemulsion formation. To demonstrate potential applications of these systems, they were employed to formulate a water-insoluble pesticide, beta-cypermethrin (beta-CP). The nanoemulsion was compared with a commercial beta-CP microemulsion in terms of the stability of sprayed formulations.
Wang
Lijuan
L
College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072, China.
Li
Xuefeng
X
Zhang
Gaoyong
G
Dong
Jinfeng
J
Eastoe
Julian
J
D004655:Emulsions / Q000737:chemistry*; D009821:Oils / Q000737:chemistry*; D010575:Pesticides / Q000138:chemical synthesis / Q000737:chemistry*; D011722:Pyrethrins / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry; D014867:Water / Q000737:chemistry
D004655:Emulsions; D009821:Oils; D010575:Pesticides; D011722:Pyrethrins; D013501:Surface-Active Agents; D014867:Water; C017160:cypermethrin