Preparation and Characterization of Fe3O4@nSiO2@mSiO2–NH2 Core–Shell Microspheres for Extracting Allura Red from Aqueous Solution
Abstract
Allura red (AR) is a water-soluble synthetic colorant often used as an additive in the food industry, but excess AR can be harmful to human health. In this work, we report the development of a new removal method for AR by using amino-functionalized microspheres with Fe3O4 cores and twolayer shells composed of SiO2 particles and perpendicularly aligned mesoporous SiO2 (designated Fe3O4@nSiO2@mSiO2–NH2). The material exhibits good dispersibility in aqueous solutions and a high saturation magnetization of 45.68emug, and can be magnetically separated efficiently with an external magnet. Importantly, the material has great adsorption capacity of 29.6mgg for AR and the capacity for reuse with a simple treatment. The adsorption process is very fast and the kinetics data are consistent with a pseudo-second order model. Based on these, a rapid and efficient method for extraction and analysis of AR in water and soft drinks has been established.
