Preparation and performance study of zeolitic imidazolate frameworks-8 loaded clopyralid nanoparticle drug delivery system
Clopyralid is a hormone-type heterocyclic herbicide that has been widely used to control broad-leaved weeds in crops such as rapeseed,corn,and wheat.However,clopyralid is water soluble and mobile,and it has been recognized as a new type of pollutant in agricultural wastewater.The preparation of sustained-release formulations of clopyralid can effectively reduce its negative impact on the environment.This study prepared a clopyralid loading system using zeolitic imidazolate frameworks-8(ZIF-8)as a carrier and optimized the loading method.The morphology,size distribution,chemical functional groups,crystal structure,thermal stability and other indicators were characterized by transmission electron microscopy,dynamic light scattering,X-ray diffraction,Fourier transform infrared spectroscopy,thermogravimetric analysis,and N2 adsorption desorption.The release mechanism and herbicidal activity were also studied.The results showed that clopyralid could be successfully loaded into the ZIF-8 carrier,with the particle size being approximately 219.3 nm after loading with clopyralid.The drug loading rate reached a maximum of 43.6%,and its release mode was most consistent with the Weibull model(R2=0.9999).Additionally,the results of bioactivity experiment against Echinochloa crus-galli showed that the herbicidal activity of clopyralid was not reduced after loading into ZIF-8,and even at a high concentration,ZIF-8 could play a certain synergistic effect.This study provided a reference for the preparation of herbicide loading systems based on ZIF-8 carrier.
clopyralidzeolitic imidazolate frameworks-8nanoparticle drug delivery systempreparation methodEchinochloa crus-galli