Synthesis of a Composite Based on Humic Acid Tuned to Sorbed Copper Ion

Abstract

We obtained modified humic acid-based cross-linked composite pre-tuned to the sorbed copper ion. The composite synthesis had three stages. At first, we obtained prepolymerization complex using humic acids isolated from Shubarkol deposit oxidized coals and multi-walled carbon nanotubes (MWCNTs) with template (CuSO4). We used ultrasonic activation for uniform dispersion of multi-walled carbon nanotubes. Second stage comprised copolymerization in the presence of amine and cross-linker; here the prepolymerization composite complex with the template was fixed in certain nodes of polymer network. At the third stage, acid hydrolysis destroyed the bonds of the template with the composite macromolecules, the template was removed, and imprints complementary to the template in shape, size, and functionality were formed and retained “molecular memory”. Such tuning forms adsorption centers in the polymer network of the composite, which can repeatedly and highly specifically interact with the template, and highly selectively extract target molecules from solution, leading to significant increase in sorbent capacity. The reaction was controlled by direct and back titration, and added amine, which was determined using Elementar Unicube elemental analyzer. The crosslinked composite can be used as a selective sorbent tuned to a specific metal ion.