萘磺酸盐分散剂在不同晶型吡唑醚菌酯颗粒表面吸附性能

Adsorption properties of naphthalenesulfonate dispersant onto different crystal pyraclostrobin particle surfaces

通过X射线衍射仪(XRD)、差示扫描量热仪(DSC)、紫外光谱(UV)、傅里叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)和扫描电子显微镜(SEM)测试,研究了萘磺酸盐分散剂在两种晶型吡唑醚菌酯颗粒表面的吸附性能。两种晶型吡唑醚菌酯吸附萘磺酸盐分散剂后,晶型未发生改变;两种晶型吡唑醚菌酯吸附动力学均符合伪二级动力学方程,晶型ⅡEa=16.04 k J·mol^(-1),晶型ⅣEa=12.42 k J·mol^(-1),均为物理吸附;吡唑醚菌酯晶型Ⅱ、晶型Ⅳ吸附等温线均符合Langmuir模型,晶型Ⅱ的吸附焓变?Had为20.64 k J·mol^(-1),吸附过程为吸热过程,温度升高有利于萘磺酸盐甲醛缩合物(D425)在晶型Ⅱ颗粒表面的吸附;晶型Ⅳ的吸附焓变?Had为-15.26k J·mol^(-1),吸附过程为放热过程,温度升高不利于D425在晶型Ⅳ颗粒表面的吸附。

The adsorption properties of naphthalenesulfonate dispersant onto different crystal pyraclostrobin particle surfaces were characterized by XRD, DSC, UV, FTIR, XPS, and SEM. The results suggested that adsorption of naphthalenesulfonate dispersant didn＇t change pyraclostrobin crystal. The adsorption kinetics shows that the adsorption dispersant D425 onto different crystal pyraclostrobin particle surfaces corresponds with pseudo-second-order adsorption rate equation. The adsorption process of different crystal pyraclostrobin is physical adsorption with Ea（crystal Ⅱ）=16.04 k J·mol（-1） and Ea（crystal Ⅳ）=12.42 k J·mol（-1）.The adsorption process of different crystal pyraclostrobin is fitted with Langmuir isotherm equation. The values of crystal Ⅱ △Had = 20.64 k J·mol（-1） indicated that the adsorption process of crystal Ⅱ is endothermic process, and higher temperature is beneficial to the D425 adsorbed onto crystal Ⅱ particle surfaces. The values of crystal Ⅳ△Had=-15.26 k J·mol（-1） indicated that the adsorption process of crystal Ⅳ is exothermic process, and higher temperature is not beneficial to the D425 adsorbed onto crystal Ⅳ particle surfaces.