Preparation of dithiocarbamate polymer brush grafted nanocomposites for rapid and enhanced capture of heavy metal ions

High-density and narrow-distribution dithiocarbamate (DTC) functionalized polymer brush grafted SiO2 nanocomposites (DTC-PGMA@ SiO2) were synthesized via surface initiated atom transfer radical polymerization (SI-ATRP) and subsequent DTC functionalization, which could serve as an efficient nanostructured adsorbent material. Systematic characterization was performed to identify the sea anemone like core-brush structure. More importantly, the DTC-PGMA@ SiO2 adsorbent exhibited remarkable performance in capturing heavy metal ions from water. The adsorption behaviour, including the effect of pH, adsorption kinetics, adsorption isotherms, adsorption thermodynamics and adsorption mechanism, was investigated in detail. Interestingly, the adsorbent complexes show different color changes depending upon the species of adsorbed ions, indicating that the DTC-PGMA@ SiO2 can be potentially used as a sensor for metallic contaminants in water bodies. The regeneration experiments showed that the adsorbent is both cost-effective and sustainable. The high-capacity and rapid adsorption of metallic ions, which are due to the well-defined core-brush structure, large specific surface area and strong binding ability of DTC groups, make this adsorbent material promising in the capture of heavy metal ions from contaminated water.