Synthesis of novel collagen-based aerogel with slit-shaped pore structure: Study on its adsorption mechanism on copper ions

In this study, (SA/BHC)@TE aerogel is successfully prepared based on hydrogen bonding between three components, covalent cross-linking between bovine hide collagen (BHC) and tannin extract (TE), and the gelation of sodium alginate (SA). The adsorption properties of (SA/BHC)@TE on Cu(II) are systematically analyzed through a combination of simulations and specific experiments. Firstly, DFT simulations are performed to rapidly predict the possibility of interactions among BHC, SA and TE. Then, experiments are performed to indicate that the (SA/ BHC)@TE aerogel is endowed with a core-shell structure, a slit-shaped pore structure, and abundant active centers (-OH, -COOH, -NH2 and -CONH-). (SA/BHC)@TE has a maximum removal efficiency of 90.3 % for Cu (II). Consequently, (SA/BHC)@TE successfully achieves selective adsorption of specific ions Cu(II) from the mixture with a distribution coefficient of 11.12 L/g. It suggests that the adsorption is mainly multilayer adsorption and chemisorption. Furthermore, the FTIR and XPS studies reveal that the adsorption of Cu(II) onto (SA/BHC)@TE is the result of the synergistic effect of coordination, ion exchange and electrostatic interaction. In addition, the (SA/BHC)@TE aerogel is easy to separate and recycle. Therefore, this paper has important implications for the development of selective adsorbents for Cu(II) as well as for the resource utilization of collagen.