Preparation And Stability Study Of Pyridoxone Aqueous Suspension And Atrazine Aqueous Suspension

Pesticide aqueous suspension is a multi-phase dispersion system in which a solid drug is dispersed in an aqueous medium with a certain degree of dispersion.Due to the absence of organic solvents,suspensions are less dangerous to the user and the entire environment and are relatively safe during storage and transportation.In addition,the performance of the suspension is superior,with good dispersion,high suspension rate,good spreading and adhesion ability on the surface of the plant,and significant and long-lasting efficacy.Some pesticide solution suspensions have the disadvantages of poor stability and easy precipitation.This is mainly due to the phenomenon of flocculation and aggregation caused by the interaction of particles in the aqueous suspension system of pesticides and delamination and particle deposition due to gravity.In order to maintain the physical stability of the water suspension agent within a certain period of time,it is necessary to control the suspension aggregation,sedimentation and crystal growth through process and process.In this project,a series of research methods were used to prepare 500g/L atrazine suspension and 25% pymetrozine aqueous suspension with stable performance.The stability issues that occurred during its storage were studied.The content and results of this study are as follows:1.The flow point method was used for the preliminary screening of the dispersants of the atrazine suspension concentrate,and the optimal combination and dosage of the dispersants were determined based on the Zeta potential and the size of the particles.Based on this,combined with the physicochemical properties of the atrazine suspension after hot storage,the good formulation for 500g/L atrazine suspension concentrate and the 25% pymetrozine aqueous suspension was determined.2.The flow behaviors of the two pesticide solution suspensions all conformed to the Herschel-Balkeley rheological model.They have the rheological properties of shear thinning,and their values are in the range of yield values required for stable storage of the pesticide water suspension system.Thus,it was determined that the prepared two pesticide suspensions have long-term storage stability.3.The growth of micro particles from different formulations was studied,and the results showed that the growth mechanism of pesticide particles in different systems was different.In general,particle aggregation and Ostwald ripening existed at the same time,but in different systems,the importance of the effect was different,the growth of granules can not be roughly only due to particle aggregation or Ostwald ripening.