Biomass residue cellulose-based poly(ionic liquid)s: new materials with selective metal ion adsorption

Biomass residue cellulose-based poly-(ionic liquid)s (ILs) were in situ synthesized via activators generated by electron transfer for atom transfer radical polymerization in ionic liquid microemulsions. These biomass residues, including apple residue, citrus residue, and ginkgo leaf, were started with pretreatment and modification in ionic liquid microemulsions, and their structure and thermal stability were significantly altered before and after modification as confirmed by scanning electron microscopy and thermogravimetric analysis. Fourier-transform infrared spectroscopy and 31P nuclear magnetic resonance spectroscopy were used to investigate the molecular structure of the biomass residue cellulose-based poly-ILs. In addition, the adsorption performance of the biomass residue cellulose-based poly-IL adsorbents for heavy metal ions, such as Cd(II), Zn(II), Cr(IV), Cu(II), Mn(II), Ni(II), and Pb(II), in water were investigated. Results show that the prepared adsorbent possesses good thermal stability and certain adsorption capacity for metal ions in water, especially for nickel ions (93.91 mg/g). The prepared adsorbent also exhibits remarkable performance in the field of biomass residue utilization and novel poly-IL adsorbents.