Structure-effect Relationship Of Wetting Agent Structure And Foam Performance

In the process of pesticide preparation and auxiliary agent,Foam is easy to appear,and the foam performance is affected by many factors,such as surface tension,liquid membrane charge,Surfactant concentration,electrolyte,etc..Wetting agents are a large class of pesticide additives,but their foam properties are rich and affect the efficiency of pesticide application.Therefore,it is of great reference value to explore the foam properties of different Surfactant from the molecular structure.The influence of the molecular structure of wetting agent(Surfactant)on the properties of the foam was investigated.The surface tension and the potential were measured to analyze the adsorption property of the system and the aggregation ability of the molecules in the solution,high potential,good foam performance.Different molecular structures of wetting agents result in different adsorption properties on the surface and different diffusion rates of monomer molecules in solution,which affect the foam properties of Surfactant agents.In this paper,the foaming properties of four kinds of sulfonates,such as Sodium Sodium Dodecyl sulfonate,sodium dodecyl benzene sulfonate(LAS),Sodium Secondary alkylsulfonate(SAS)and sodium alkenesulfonate(AOS),in pure water were studied.It was found that the same hydrophilic group of Surfactant was formed in pure water,the foam properties of LAS are better when the chain length is larger than that of SDS,and the space steric resistance of the branched chain sulfonates SAS is larger because the hydrophilic group is located in the vertical direction of the alkyl chain,compared with the straight chain structure,the foam has poor performance,so it is suitable for pesticide application.For Hydrophilic wetting agents with different chain lengths(C10,C12,C16),the foam properties of sulfonates and sulfates are affected by the molecular diffusion rate,the Foam Properties are C12> C16 > C10;carboxylate systems are affected by the surface activity,and the foam properties are: C16 >C12 > C10.Foam properties of three different hydrophilic Surfactant in deionized water: Sulfate > Sulfonate > carboxylate.This study is an innovative application of Surfactant in pesticide saturated solution to investigate the effect of molecular structure on the properties of pesticides.In acetamiprid saturated solution,the longer AOS chain and the branched-chain structure of SAS foam have better performance,the presence of counter-ions increases the surface adsorption amount,reduces the steric hindrance,and the foam has better performance.For Las and SDS,Surfactant precipitation occurs easily,which makes the performance of the wetting agent foam worse than that in pure water.For the application of sulfates,sulfates and carboxylates with different chain length in pesticide saturation,it is found that the foam performance is worse than that in water.The order of foam properties is: Sulfate >sulfonate>carboxylate due to the different binding stability between hydrophilic group and counter-ion.