Enhanced π−π stacks of aromatic ring-rich polymer adsorbent for the rapid adsorption of organic dyes

Adsorption technique has been proven its promising advantages in the adsorptive removal of contaminants from dyeing wastewater. However, a rapid adsorption is still difficult for adsorbents due to the limitations of the common driving forces. Aromatic ring structure of organic dyes gives us inspirations to develop π-π stacking interactions to trap adsorbates. Herein, a new kind of organic polymer adsorbent with rich aromatic ring was designed to remove organic dyes. As-obtained aromatic ring-rich polymer adsorbent can capture dye molecules mainly via the enhanced π-π stacking interactions. Thus, a rapid adsorption can be achieved even the adsorption experiments were performed in a wide pH range. After contacting for 3 min, removal efficiency for methylene blue dye reached high up to 94%. Furthermore, the difficulty for regenerating dyes-adsorbed adsorbents by using NaOH or HCl also confirmed the little effect of solution pH values on π-πstacking interactions. This work provides new insight into the design of adsorbents with rich aromatic ring to improve the adsorption rate.