Zinc Schiff base modified MCM-41 (Zn-MCM-41) was prepared by co-condensation method

uses 3-aminopropyl triethoxysilane (APTES)

salicylaldehyde and zinc ions as modifying agent. The chlorpyrifos/Zn-MCM-41 (CH-Zn-MCM-41) system was prepared by impregnation method

employing chlorpyrifos as a model drug. The structures and distribution form of chlorpyrifos of MCM-41

amino functionalized MCM-41 (NH2-MCM-41)

salicylaldehyde Schiff base functionalized MCM-41 (SA-MCM-41) and Zn-MCM-41 were systematically characterized by X-ray diffraction assay(XRD)

N2 adsorption-desorption

Fourier transform infrared spectroscopy(FTIR)

differential scanning calorimeter(DSC) and X-ray photoelectron spectroscopy(XPS). The adsorption capacity of MCM-41 for chlorpyrifos before and after modification was discussed. The adsorption kinetics

adsorption thermodynamics and sustained release performance of as-synthesized system were also investigated. The results showed that the order structure of NH2-MCM-41 and SA-MCM-41 was still maintained by co-condensation method. After modification of MCM-41

the adsorption capacity of chlorpyrifos increased from 54 mg·g-1 to 186 mg·g-1

an increase of 244% due to the coordination effect between Zn-MCM-41 and chlorpyrifos. The adsorption kinetics and adsorption thermodynamics of MCM-41 on chlorpyrifos before and after modification were in accordance with pseudo-first-order kinetic model and Freundlich model

respectively. The releasing behavior of CH-Zn-MCM-41 could be described by Riger-Peppas equation which indicates that the chlorpyrifos release was controlled by Fick diffusion.