Abstract:
OA-AP, DTAB-AP, DDBAB-AP complexes were synthesized by introducing surfactants of OA, DTAB and DDBAB into attapulgite (AP). The complexes were systematically characterized. The appearance of new diffraction peaks at low angle indicated a new lamellar structure of OA (DTAB, DDBAB)-AP complexes. Then, the pesticide avermectin (AV) composites of AV/DTAB-OA-AP, AV/DDBAB-OA-AP, sodium alginate (SA) @AV/DTAB-OA-AP and SA@AV/DDBAB-OA-AP were prepared and investigated detailedly. The basal spacings of AV/DTAB-OA-AP and AV/DDBAB-OA-AP were bigger than those of OA-AP and DTAB(DDBAB)-AP. The existences of AV, surfactants and SA molecules of the composites were further confirmed. Furthermore the effect of SA on AV release behaviors of SA@AV/DTAB (DDBAB)-OA-AP microspheres was investigated and compared. Compared to AV/DTAB (DDBAB)-OA-AP, the released rate of the microspheres decreased remarkably. The AV release behaviors of AV/DTAB (DDBAB)-OA-AP could be fitted with pseudo second-order model, while the first-order model was better to describe those of the microspheres. Finally, the bioassay of the microspheres were studied and analyzed. The microspheres had a longer duration and control effect on Mythimna separata. This study could be helpful to provide a pesticide delivery system to improve the utilization efficiency of pesticides.
摘要:
OA-AP,DTAB-AP,通过引入OA表面活性剂合成了DDBAB-AP配合物,DTAB和DDBAB成凹凸棒石(AP)。对配合物进行了系统表征。在低角度出现新的衍射峰表明OA的新层状结构(DTAB,DDBAB)-AP复合物。然后,农药阿维菌素(AV)/DTAB-OA-AP复合材料,AV/DDBAB-OA-AP,制备并详细研究了海藻酸钠(SA)@AV/DTAB-OA-AP和SA@AV/DDBAB-OA-AP。AV/DTAB-OA-AP和AV/DDBAB-OA-AP的基础间距大于OA-AP和DTAB(DDBAB)-AP的基础间距。AV的存在,进一步证实了复合材料的表面活性剂和SA分子。此外,研究并比较了SA对SA@AV/DTAB(DDBAB)-OA-AP微球的AV释放行为的影响。与AV/DTAB(DDBAB)-OA-AP相比,微球的释放率显著下降。AV/DTAB(DDBAB)-OA-AP的AV释放行为可以用伪二阶模型拟合,而一阶模型更好地描述了微球的那些。最后,对微球的生物测定进行了研究和分析。微球具有较长的持续时间和对Mythimna分离的控制作用。本研究有助于提供一种提高农药利用效率的农药投放系统。