Efficient iodine capture by a sesbania gum-based polymeric adsorbent for reutilization in bacterial decontamination

The past several decades have witnessed great achievements in the development of advanced materials for disposing of iodine that poses a risk to public health. However, little attention has been paid to the reutilization of the captured iodine. Herein, we report on the modification of sesbania gum (SG) with polyvinylpyrrolidone (PVP) via a radical polymerization strategy, and we investigate the modified SG (mSG) as an adsorbent for iodine capture, as well as the use of the captured iodine for antibacterial purposes. The PVP loading and hydrophilic-hydrophobic balance of mSG were controlled facilely by tuning the feed ratio of SG to N-vinyl-2-pyrrolidone. The as-obtained mSG served as an efficient adsorbent for iodine capture from solution, by undergoing a complexation reaction of pyrrolidone groups with I-2 and polyiodide (i.e., I-3(-)). More significantly, after a series of in vitro antibacterial tests against Escherichia coli (10(8) CFU.mL(-1)) and column filtration assays, the as-captured iodine on mSG could be reutilized as an antibacterial agent to combat pathogens. We believe that this proposed strategy based on the synergism of iodine adsorption and reuse should have great potential for environmental remediation and public healthcare.