Green synthesis of polyol functionalized cotton linter polymer adsorbents by the hydrothermal method: Effects of the structure of the ligands for boron anionic species capture

The complex and diverse forms of boron in aqueous solutions have presented a major challenge for boron separation. Boron can be chemically complexed with polyols to achieve the purpose of separation. It is of great significance to clarify the mechanism of polyol ligand capturing boron anion for optimizing the best ligand. The facile environmentally friendly functionalization of cotton linter polymer with amino-polyol was successfully demonstrated and resulted in essential polyhydroxy ligands containing amines for strong interactions with boron. The adsorption capacity of the boron adsorbents with the most –OH and N is up to 27.88 mg/g. The presence of the N, high vicinal diol content, and the branched structure all have a positive effect on the complexation efficiency. Optimization of the ligand structure is helpful to increase the boron uptake and it is of great significance to design the best adsorbent for boron separation from salt lake brine.