Boric acid bridged cyclodextrins-based polymers for selective adsorption of binary dyes

Abstract

Organic aerogel has attracted much attention these days due to its wide applications to multiple daily fields. Except for designing processing procedures, we focused on enhancing the hierarchical porosities by introducing cavities of cyclodextrins (CDs) here in polymeric networks crosslinked by boric acid (BA). As confirmed by a series of instrumental analyses such as FT-IR, XRD, SEM, BET, EDS, XPS and ζ potential, BA was successfully employed as the “bridge-like” moieties to connect independent CDs subunits together for affording CDs-based polymers (BA-CD) via the one-step method in aqueous solutions. Particularly, BA-CD exhibited expected selective capacity during the experiment of competitive adsorption by fully using diverse porosities generated by both polymeric networks and the host cavities. Theoretical calculations were further performed to model the possible monomeric structure in BA-CD, and the diverse behaviors in host-guest inclusion towards targeted organic dyes by using CD and BA-mono-bridged CD dimeric structure, indicating that both molecular recognition of CD cavity and synergistic cooperation among crosslinked CD moieties play significant roles in selectively absorbing binary dyes.