FTIR,XPS和SEM研究聚羧酸盐分散剂在吡唑醚菌酯颗粒表面的吸附性能

A Study of the Adsorption Property of Dispersant of Polycarboxylate onto Pyraclostrobin Particle Surfaces by Using FT-IR,XPS and SEM

采用傅里叶变换红外光谱、X射线光电子能谱和扫描电子显微镜相结合的方式,从微观角度研究梳状聚羧酸盐分散剂在吡唑醚菌酯颗粒表面的吸附性能,为聚羧酸盐分散剂在吡唑醚菌酯悬浮剂中的应用提供理论依据。研究结果表明:吡唑醚菌酯吸附聚羧酸盐分散剂后,红外谱图未出现新的吸收峰,聚羧酸盐分散剂与吡唑醚菌酯之间主要是物理吸附,范德华力是聚羧酸盐分散剂与吡唑醚菌酯颗粒表面结合的主要作用力。吡唑醚菌酯颗粒吸附聚羧酸盐分散剂后,吡唑醚菌酯颗粒界面的N和Cl电子峰强度减弱,C和O电子峰强度明显增强,还出现了Na的电子峰,这主要是聚羧酸盐分散剂中C,O和Na的贡献,说明聚羧酸盐分散剂在吡唑醚菌酯颗粒表面形成了良好的吸附。并以Cl元素为特征元素,计算出聚羧酸盐分散剂在吡唑醚菌酯颗粒表面的吸附层厚度约为1.22nm。用扫描电子显微镜研究了样品的形貌,吸附聚羧酸盐分散剂后,原本光滑的吡唑醚菌酯颗粒表面吸附了很多细小的颗粒,且有序分布,这是由于分散剂疏水集团对吡唑醚菌酯颗粒形成了包覆,亲水基团充分外露,从而有效阻止吡唑醚菌酯颗粒间的团聚,提高了吡唑醚菌酯悬浮剂的物理稳定性。

The main methods in performing the study of the adsorption properties of polycarboxylate onto pyraclostrobin particle surfaces were FTIR,XPS and SEM from the microscopic view,and the study results provided the theory basis for the application of dispersant polycarboxylate in pyraclostrobin suspension concentrate.The results showed:Infrared spectra is not a new adsorption peak after pyraclostrobin adsorbed polycarboxylate dispersant;the results suggested that physical adsorption is mainly between pyraclostrobin and polycarboxylate dispersant;van der Waals force is the main force.After adsorption of polycarboxylate dispersant by pyraclostrobin particles,the peak intensity of N and Cl of the interface of pyraclostrobin particle decreased sharply,while the adsorption of C and O of the interface of pyraclostrobin particle increased,the Na peak appeared also after pyraclostrobin adsorbed the dispersant.This is mainly the polycarboxylate dispersant C,O and Na contribution,which indicates that polycarboxylate dispersant was adsorbed on the surface of pyraclostrobin.The calculating thickness of the adsorption was 1.22 nm by the characterized element Cl.The morphology of the sample was investigated by scanning electron microscopy.After the polycarboxylate dispersant was adsorbed,many fine particles were adsorbed on the surface of the original smooth pyraclostrobin particles,which were distributed in an orderly manner.This was attributed to the fact that dispersant hydrophobic group formed a coating for pyraclostrobin particles,then hydrophilic groups were fully exposed,thus effectively blocking the pyraclostrobin agglomeration between particles and thereby enhancing the physical stability of pyraclostrobin suspension.