Adsorption behavior of amino functionalized MCM-41 on chlorogenic acid from Eucommia ulmoides leaves

In this study, an amino-functionalized MCM-41 mesoporous material was prepared via hydrothermal method for the adsorption of chlorogenic acid from Eucommia ulmoides leaf extracts. The as prepared NH2-MCM-41 was characterized by X-ray diffraction, FT-IR spectroscopy and N2 adsorption–desorption isotherms. The results show that have good mesoporous structure. The batch experiments showed that adsorption process was more in line with the pseudo-second order kinetic model, which indicated the chemisorption played an important role in the adsorption process; Isothermal adsorption results showed that the adsorption of chlorogenic acid by NH2-MCM-41 was more consistent with Langmuir model, indicating that multilayer adsorption process occurred. Thermodynamic analyses demonstrated that the chlorogenic acid adsorption on NH2-MCM-41 abided by a spontaneous and exothermic procedure with entropy decreased. The purity of chlorogenic acid could be increased from 17.36 to 85.60% under the optimal conditions t = 9 h, temperature = 333 K, pH 6. These results indicated that NH2-MCM-41 is a promising adsorbent for the separation and purification of chlorogenic acid from Eucommia ulmoides leaf extracts.