Studies on cloud point of agrochemical microemulsions

As part of our studies on green agrochemical formulations, four o/w agrochemical microemulsions have been prepared using five non-ionic surfactants with various hydrophilities and one co-surfactant. The effects of various formulation conditions, including surfactants, surfactant concentration, mixture of surfactant with various concentrations, pesticides in oil phase and water quality in the continuous medium on the cloud points of microemulsions have been investigated. The results showed that the values of the cloud point of microemulsions were depended on the nature of agrochemical, the surfactants used and the concentration of surfactants. Surfactants with higher HLB value at same concentration produce more stable agrochemical microemulsions, i.e. with higher cloud point. The results showed that the match between surfactant and oil phase or pesticide oil phase was the key to formulate stable microemulsions, However, the water quality was showed almost no effect on the cloud point of the agrochemical microemulsions in the studies. (C) 2000 Elsevier Science B.V. All rights reserved.