Preparation and Ion Recognition Characteristics of a Trichloroacetic Acid Surface-Imprinted Material

In this work, a trichloroacetic acid (TCAA) surface-imprinted material with high performance was prepared. In an aqueous solution, the molecules of the cationic monomer acryloyloxyethyl-trimethyl ammonium chloride (DAC) arranged around the template TCAA anion via electrostatic interaction. By initiating of the surface-initiating system of -NH2/S2O8(2-), the graft/cross-linking polymerization of DAC and the crosslinker N,N'-Methylenebisacrylamide and the TCAA surface-imprinting were simultaneously carried out on SiO2 particles, forming TCAA anion surface-imprinted material IIP-PDAC/ SiO2. With monochloroacetic acid (MCAA) and phenylacetic acid (PAA) as two contrast acids, the recognition character of the imprinted material IIP-PDAC/SiO2 was investigated. This imprinted material possesses special recognition selectivity and excellent binding affinity for TCAA anion. The binding amount of IIP-PDAC/SiO2 particles for TCAA reaches 0.93 mmol/g, whereas their binding amounts for MCAA and PAA are only 0.48 mmol/g and 0.15 mmol/g, respectively. The selectivity coefficients of IIP-PDAC/SiO2 for TCAA relative to MCAA and PAA anions are 3.61 and 9.12, respectively.