Easy fabrication of aromatic-rich cellulose-urethane polymer for preferential adsorption of acetophenone over 1-phenylethanol

A novel aromatic-rich cellulose-urethane polymer (ACUP) was easily fabricated by crosslinking cellulose with 4,4',4-triphenylmethane triisocyanate for preferential adsorption of acetophenone (AP) over 1-phenyethanol (PE). The successful synthesis of ACUP was confirmed by the instrumental analyses, e.g., FTIR, TG, XPS, FE-SEM, C-13 CP/MAS NMR and XRD. For single-solute adsorption of AP or PE onto ACUP, the effects of adsorbent dosage, agitation speed, time, solute concentration and temperature were systematically investigated. The overall adsorption process was exothermal and spontaneous in nature, and followed the pseudo-second-order kinetic rate equation and Freundlich isotherm model. Competitive adsorption studies concerning the effects of phenyl content in ACUP adsorbent, pH and ionic strength were also presented, in which ACUP showed much higher affinity for AP over PE. In addition, ACUP was examined as a column packing material for adsorptive separation of the equimolar mixture of AP-PE, showing excellent separation capability. The easily-regenerated and recyclable features of ACUP were demonstrated by adsorption-desorption cycles in both batch and continuous modes. Furthermore, a possible mechanism for the preferential adsorption of AP over PE, which may be associated with pi-pi and hydrogen bonding interactions was suggested on the basis of experimental and theoretical results.