Porous multifunctional phenylcarbamoylated-β-cyclodextrin polymers for rapid removal of aromatic organic pollutants

In this work, polymers containing a large number of benzene rings and multiple functional groups were designed to remove aromatic organic pollutants. Using tetrafluoroterephthalonitrile (TFTPN) as a rigid crosslinking agent to crosslink different functionalized phenylcarbamoylated-beta-cyclodextrin derivatives to prepare a series of porous multifunctional cyclodextrin (CD) polymerizations, including three preliminary polymerized adsorption materials and a mix beta-cyclodextrin polymer (X-CDP) prepared via a secondary crosslinking procedure of the above three materials. The X-CDP preparation process connects the pre-formed nanoparticles and increases the presence of linkers inside the particles. At the same time, X-CDP exhibited porous structure with various functional groups such as nitro, chlorine, fluorine, and hydroxyl. Those special characteristics render this material with good adsorption ability towards various aromatic organic pollutants in water, including tetracycline, ibuprofen, dichlorophenol, noffloxacin, bisphenol A, and naphthol. Especially, the maximum adsorption capacity for tetracycline at equilibrium reached 110.56 mg-g(-1), which is competitive with the adsorption capacities of other polysaccharide adsorbents. X-CDP removed organic contaminants much more quickly than other adsorbents, reaching almost similar to 95% of its equilibrium in only 30 s, and the rate constant reaches 2.32 g.mg(-1).min(-1). The main adsorption process of the pollutants by X-CDP fitted the pseudosecond-order kinetic and Langmuir isotherm well, indicating that the adsorption process is monolayer adsorption. Moreover, X-CDP possessed the good reusability where the pollutant removal rate was only reduced 8.3% after five cycles. Such advantages render the polymer great potential in the rapid treatment of organic pollutants in water bodies.

Automated summary

This study designed polymers with numerous benzene rings and multiple functional groups for the removal of aromatic organic pollutants in water. Through a special crosslinking method, porous multifunctional cyclodextrin polymers were prepared and exhibited excellent performance in adsorbing various organic pollutants in water, with a maximum adsorption capacity of 110.56 mg/g(-1) for tetracycline and a rapid adsorption rate reaching 95% equilibrium in just 30 seconds. Additionally, the polymer showed good reusability, maintaining a high removal rate after multiple cycles.