From normal crosslinking to core–shell structure: Improved performance of β-cyclodextrin based adsorbent toward efficient separation of acetophenone and 1-phenylethanol

•CD@PTTI-3 exhibits higher AP/PE selectivity than normal crosslinked polymers.•The cage-type stacking of β-CD in the core favors preferential uptake of AP.•β-CD crystal and PTTI shell synergistically separate AP and PE.•The selective adsorption was verified by DFT calculations.