松香基氨基化聚合物微球对胭脂红的吸附热力学及动力学

Thermodynamics and kinetics of carmine adsorption on rosin-based aminated polymer microspheres

研究了松香基氨基化聚合物微球[P(RAG/St/NH2)]在不同pH值和吸附时间对胭脂红的吸附,以及吸附动力学、热力学特性,初步探讨了吸附反应机理。采用FT-IR、 XPS、 SEM和热重等对微球进行了表征。结果表明:pH=2时, P(RAG/St/NH2)微球对胭脂红的吸附效果最好,并且吸附前后微球球形无变化;微球对胭脂红的吸附符合伪二级吸附动力学和Langmuir等温吸附模型,说明吸附过程是以化学吸附为主;探究了温度为303、308、313和318 K的吸附过程,发现ΔH> 0、ΔG<0、ΔS> 0,表明吸附属于自发吸热熵增的过程,升高温度有利于微球对胭脂红的吸附。

The effect of solution pH and time on the adsorption of carmine by rosin-based aminated polymer microspheres(P(RAG/St/NH2)) was studied. The thermodynamic and kinetic behavior of carmine adsorption on [P(RAG/St/NH2)]were investigated. The microspheres were characterized by FT-IR, XPS, SEM and TGA before and after the adsorption. The results showed that P(RAG/St/NH2) had the best adsorption of carmine at pH=2, and there was no change in the sphere shape of the microspheres before and after adsorption. The adsorption behavior agreed with the pseudo-second-order adsorption kinetics and the Langmuir isotherm model, indicating that the adsorption process belonged to the monolayer chemisorption. At different temperatures, the adsorption process will be ΔH>0,ΔG<0,ΔS>0;indicating that adsorption belonged to the process of spontaneous endothermic and entropy increase. The increase of temperature favored the adsorption of carmine.