Preparation of atrazine surface-imprinted material MIP-PSSS/SiO2 and study on its molecule recognition character

Abstract

By using a novel molecular surface-imprinting technique, “synchronously graft-polymerizing and imprinting” method established by our group, a pesticide molecule surface-imprinted material was prepared successfully for the removal of pesticide residues from water. The micron-sized silica gel particles were first surface-modified with coupling agent γ-aminopropyltrimethoxysilane (AMPS), obtaining the modified particles AMPS-SiO2, onto whose surfaces primary amino groups were introduced. The anionic monomer sodium p-styrenesulfonate (SSS) was used as functional monomer and N,N′-methylenebisacrylamide (MBA) was used as crosslinker. In aqueous solution, the monomer molecules were arranged around the template molecule, atrazine molecule that is an extensively used herbicide, through electrostatic interaction. By initiating of the redox surface-initiating system of -NH2/S2O82−, the graft/cross-linking polymerization of SSS on SiO2 particles and the surface imprinting of atrazine molecule were simultaneously carried out, forming atrazine molecule surface-imprinted material MIP-PSSS/SiO2. With propoxur and pirimicarb, which are also two pesticides as two contrast substances, the recognition performance of the atrazine molecule surface-imprinted material MIP-PSSS/SiO2 was investigated in depth. The experimental results show that MIP-PSSS/SiO2 particles possess special recognition selectivity and excellent binding affinity for atrazine. The binding capacity of atrazine on MIPPSSS/ SiO2 particles can get up to 61mg/g, and relative to propoxur and pirimicarb, the selectivity coefficients of MIPPSSS/ SiO2 for atrazine are 9.69 and 8.79, respectively.