A phenyl-rich β-cyclodextrin porous crosslinked polymer (PCD-PCP) with high phenyl content and consistent pore structure was used to remove the aromatic pollutants from water. The PCD-PCP was obtained through the efficient Friedel-Crafts alkylation of benzylated β-cyclodextrin with the crosslinker 4,4′-bis(chloromethyl)-1,1′-biphenyl.
Impressively, PCD-PCP(H) with high crosslinking density exhibited a notable sorption ability and good recyclability for removal of organics from contaminated water. Batch adsorption assays were carried out using 10 mg of adsorbents added into 20 mL of solution at 25 °C with initial solute concentration of 50-200 mg‧L‒1. (Figure 1) The sorbent with higher degree of crosslinking (higher phenyl content and higher specific surface area) performed better than that with lower degree of crosslinking.
The comprehensive analysis of experimental and theoretical calculations results suggested that the π–π interactions and host-guest interactions may jointly promote the uptake process, providing new insights into the development of advanced β-cyclodextrin based adsorbents for aromatic molecule adsorption.
Figure 1 Removal efficiency for aromatic pollutants with PCD-PCP of low (green) and high (brown) degree of crosslinking at 50 mg‧L‒1 polutant concentration measured from solutions containing the individual pollutants. Pollutants: nitrobenzene (NB), 2-nitroaniline (2-NA), 4-nitroaniline (4-NA), 2-chloroaniline (2-CA), 2-nitrophenol (2-NP), 2,4-dichlorophenol (2,4-DCP), 2,6-dichlorophenol (2,6-DCP), 2,4,6-TCP, BPA, bisphenol F (BPF), bisphenol S (BPS) and bisphenol AF (BPAF)
Huang, Q., Chai, K., Zhou, L., Ji, H. (2020) A phenyl-rich β-cyclodextrin porous crosslinked polymer for efficient removal of aromatic pollutants: Insight into adsorption performance and mechanism. Chemical Engineering Journal 387, 124020. doi: https://doi.org/10.1016/j.cej.2020.124020