Synthesis of poly(ionic liquid)s with high specific surface areas for m-cresol adsorption.

Developing ideal adsorbents for moving phenolic compounds from aqueous solutions remains a challenge. Herein, novel poly(ionic liquid)s (PILs) of PIL-Ba-x and PIL-An-5 were prepared via Friedel–Crafts alkylation using benzyl alcohol and aniline auxiliary cross-linking agents, respectively, for the adsorption of m -cresol in the aqueous phase. The specific surface areas and pore volumes of the synthesized PILs can be adjusted by pre-polymerization time, thereby realizing the regulation of the adsorption property of m -cresol. Results showed that the adsorption kinetics of PILs conformed to pseudo-second-order kinetics and reached adsorption equilibrium within 6 min. Their adsorption thermodynamics conformed to the Langmuir models. Based on the fitting data of the Langmuir model, the maximum adsorption capacity of m -cresol by PIL-Ba-5 can reach 228 mg/g. Moreover, the mechanism analysis showed that hydrogen bonding, electrostatic interaction, and π–π interaction promoted the adsorption of m -cresol by PIL-Ba. After the adsorption of m -cresol was separated by anhydrous ethanol, the adsorbent was recovered at least five times, and the removal efficiency was stable. [Display omitted] • Novel PILs with high specific surface areas were synthesized for adsorbing m -cresol. • The adsorption performance of PILs can be regulated by the pre-polymerization time. • The maximum adsorption capacity of the prepared PIL is 228 mg/g. • The prepared PIL-Ba-5 can quickly reach adsorption equilibrium within 6 min. • The adsorption effect of PIL remains at a high level after five cycles. [ABSTRACT FROM AUTHOR]