2种聚羧酸盐类分散剂在氟吡菌酰胺颗粒表面的吸附性能

The Adsorption Properties of Two Polycarboxylate Dispersants on the Surface of Fluopyram Particles

[目的]通过研究聚羧酸盐类分散剂在氟吡菌酰胺颗粒表面的吸附性能,为氟吡菌酰胺悬浮剂的开发提供理论依据。[方法]利用傅里叶红外光谱仪(FTIR)和紫外-可见分光光度计(UV)分析了氟吡菌酰胺与2种聚羧酸盐类分散剂Atlox Metasperse 550S (550S)和Agrilan 700(A700)之间的吸附作用力以及吸附量的影响因素。[结果]2种分散剂与氟吡菌酰胺颗粒间的吸附为物理吸附,主要的吸附作用力为范德华力;在298、308、318 K的试验温度下,达到饱和吸附量90%(或95%、99%)时分散剂550S和A700的质量浓度分别约为20 000、25 000 mg/L,吸附量随着温度的升高而降低;吸附等温线模型均符合Langmuir模型;在298 K的试验温度下,分散剂550S和A700在氟吡菌酰胺颗粒表面饱和吸附量达到90%(或95%、99%)时的时间分别为30、70 min左右,吸附动力学均符合准一级动力学模型(R2>0.94),拟合饱和吸附量与试验值相近;在试验质量浓度范围内随着NaCl质量浓度的增加,分散剂在氟吡菌酰胺颗粒表面的吸附量增加,当NaCl的质量浓度为10 g/L时吸附量达到限值;随着pH值的增加,吸附量表现出下降的趋势,当pH值小于6时,2种分散剂在氟吡菌酰胺颗粒表面的吸附量较大。[结论]分散剂550S和A700加工氟吡菌酰胺悬浮剂时为充分发挥分散剂效果,体系酸碱度要保持中性或弱碱性,适当添加NaCl保持低温提高悬浮剂的稳定性。推荐20%氟吡菌酰胺悬浮液添加分散剂550S和A700的量分别为2%和2.5%。

[Aims]This paper aims to study the adsorption of two kinds of polycarboxylate dispersants on the surface of fluopyram particles to provide theoretical basis for development of fluopyram suspension.[Methods]The FTIR and UV were used to analyze the adsorption forces between fluopyram particles and the polycarboxylate dispersants Atlox Metasperse 550S(550S)and Agrilan 700(A700),respectively.[Results]The results showed that the adsorption between the two dispersants and fluopyram particles was physical adsorption,and the main adsorption force was van der Waals force.At 298,308 and 318 K,the mass concentrations of 550S and A700 are about 20000 and 25000 mg/L respectively when the saturated adsorption capacity reaches 90%(or 95,99%),and the adsorption capacity decreases with the increase of temperature.The adsorption isotherm model was consistent with Langmuir model.At 298 K,the dispersants 550S and A700 reached a saturation adsorption amount of 90%(or 95,99%)on the surface of fluopyram particles for 30 and 70 minutes,respectively,and fit quasi-first-order kinetic model(R2>0.94).The fitting saturation adsorption amount was close to the test value.With the increase of NaCl concentration in the test concentration range,the adsorption capacity of dispersant on the surface of fluopyram particles increased.When the concentration of sodium ion is 10 g/L,the adsorption capacity of dispersants 550S and A700 on the surface of fluopyram particles reaches the limit;with the increase of pH,the adsorption capacity shows a downward trend;when the pH is higher than 6,the adsorption capacity of dispersants 550S and A700 on the surface of fluopyram particles becomes stable.[Conclusions]When the dispersants 550S and A700 are used to process fluopyram suspension,the system should maintain neutral or weak alkalinity and appropriate addition of NaCl to maintain low temperature will improve the stability of suspending agent.It is recommended that fluopyram 20%suspensions be added with dispersants 550S and A700 at 2 and 2.5%,respectively.