啶虫脒/席夫碱改性凹凸棒土缓释体系的制备与性能

Preparation and Properties of Slow-released System of Acetamiprid/Schiff Base Modified Attapulgite

采用后接枝法制备了席夫碱铜离子配合物改性凹凸棒土(Cu2+-Sal-ATP),通过浸渍法制备了啶虫脒/凹凸棒土(ATP)缓释体系。利用FTIR、XRD、N2吸附-脱附、SEM和DSC对改性凹凸棒土的结构和性质进行了表征,考察了改性凹凸棒土对农药啶虫脒的吸附行为和缓释体系的释药行为。结果表明:啶虫脒是以非晶相存在于改性凹凸棒土中,药物装载未改变载体的结构。有机改性提高了凹凸棒土对药物的吸附量,经席夫碱铜离子配位改性体系的吸附量最高,为34.17 mg/g,且吸附行为符合准二级动力学模型。Cu2+-Sal-ATP载药体系的缓释效果优于相应的席夫碱改性凹凸棒土(Sal-ATP)体系,其药物在168 h的累积释放率由23.41%降低至19.42%,且其释药行为可用Korsmeyer-Pappas动力学模型来描述。

Attapulgite（ ATP） modified by a Schiff base copper ion complex was prepared by postgrafting method. Subsequently,slow-released system of acetamiprid / attapulgite was constructed by immersion method. The modified attapulgite（ Cu^2 ＋-Sal-ATP） were characterized by FTIR,N2 adsorption-desorption isotherm,SEM,XRD and DSC. The adsorption behavior of ATP to acetamiprid and drug release behavior of slow release system were also systematically studied. The results showed that the loaded acetamiprid exists in the amorphous phase in the modified attapulgite,and the loading process does not change the structure of the carrier. The organic modification of attapulgite improves the drug loaded. The Cu^ ＋-Sal-ATP had the highest acetamiprid loaded（ 34. 17 mg / g）. The adsorption process for acetamiprid follows the pseudo-second-order kinetic model. The Cu^2 ＋-Sal-ATP / acetamiprid system exhibits better slow-release properties than schiff base modified ATP（ Sal-ATP） / acetamiprid system. The cumulative drug release rate decreased from 23. 41% to 19. 42%. Besides,their releasing curves could be described by Korsmeyer-Peppas equation.