可分散油悬浮剂作为一种环境友好农药剂型, 近年来得到快速发展。 但由于稳定机理研究相对薄弱以及精准、 量化、 微观的表征手段相对缺乏, 使得可分散油悬浮剂产品在生产和贮存的过程中容易出现析油分层、 絮凝、 膏化、 结块等现象。 X射线光电子能谱作为一种重要的表面分析技术, 具有灵敏度高、 制样简单、 样品破坏性小等特点, 常用于固体表面元素定性定量分析及原子价态分析, 适用于分散剂吸附性能及稳定机理研究。 本研究采用X射线光电子能谱、 傅里叶变换红外光谱和扫描电子显微镜相结合的方式, 在油性介质中, 从微观角度研究含多胺基锚固基团油相分散剂在丙炔噁草酮颗粒表面的吸附性能, 为该分散剂在农药可分散油悬浮剂中的应用提供理论依据。 研究结果表明: 丙炔噁草酮吸附多胺基锚固基团油相分散剂后, 丙炔噁草酮界面的Cl, N和O电子峰强度减弱, C电子峰强度增强, 说明该分散剂在丙炔噁草酮表面形成了良好的吸附。 以Cl元素为特征元素计算出该分散剂在丙炔噁草酮表面的吸附层厚度为6.746 nm。 分散剂吸附后, 红外光谱图中没有出现新的吸收峰, 分散剂与丙炔噁草酮之间的吸附是以范德华力为主要结合作用力的物理吸附。 吸附前后样品微观形貌研究表明, 未吸附分散剂的丙炔噁草酮原药颗粒表面较为粗糙, 有晶面的层状结构, 吸附分散剂后, 原药颗粒表面变得较为光滑, 晶面层状结构消失, 说明分散剂在丙炔噁草酮表面形成了包覆, 并通过非极性溶剂化链提供空间位阻, 提高丙炔噁草酮可分散油悬浮剂体系的物理稳定性。

As an environmentally friendly pesticide formulation, oil-base suspension concentrate has been rapidly developed in recent years. However, due to the relatively weak research on the stability mechanism and the relative lack of precise, quantitative and microscopic characterization methods, the oil-base suspension concentrate products are prone to oil stratification, flocculation, paste and agglomeration during production and storage. As an important surface analysis technology, XPS has the characteristics of high sensitivity, simple sample preparation and small sample destructiveness. It’s often used for qualitative and quantitative analysis of solid surface elements and atomic valence analysis, which is very suitable for dispersant adsorption performance and stability mechanism research. In this research, XPS, FITR and SEM were used to study the adsorption performance of oil phase dispersant containing polyamine anchoring group onto the surface of oxadiargyl particles in oil phase from the microscopic view, which provided a theoretical basis for the application of the dispersant in the oil-based suspension concentrate of pesticide.The results showed: after the dispersant was adsorbed, the Cl, N, O electron peak intensity at the interface of oxadiargyl was weakened, and the C electron peak intensity was enhanced, indicating that the dispersant formed good adsorption on the surface of oxadiargyl. The thickness of the adsorbed layer of the dispersant on the surface of oxadiargyl was calculated to be 6.746 nm using the Cl element as a characteristic element. There was no new absorption peak in the infrared spectrum of oxadiargyl after the adsorption of the oil-base dispersant containing polyamine anchoring group, which indicated that the adsorption between the dispersant and oxadiargyl was physical adsorption with van der Waals force as the main binding force. From the micromorphology of the sample before and after adsorption, it was showed that the surface of the oxadiargyl particles before absorbing the dispersant was rough and had a lamellar structure, while the surface became smooth and the layered structure disappeared after absorbing the dispersant. The difference illustrated that the dispersant containing polyamine anchoring groups formed a coating on the surface of oxadiargyl and improved the physical stability of oxadiargyl oil-base suspension concentrate by providing steric hindrance through the non-polar solvated chains.