β-Cyclodextrin-based oil-absorbents: Preparation, high oil absorbency and reusability

This article reports the first oil-absorbents consisting of β-cyclodextrin (β-CD) and showing high oil absorbency. To prepare such oil-absorbents, a β-CD derivative (β-CD-A) was synthesized and then underwent copolymerizations with octadecyl acrylate (ODA) and butyl acrylate (BA) in the presence of AIBN as initiator, yielding a cross-linked oil-absorbent. Herein β-CD-A served simultaneously as a co-monomer, cross-linking agent, and pore-forming agent. The oil-absorbent containing CD moieties showed much higher oil absorbency (CCl4, 79.1 g; CHCl3, 72.8 g; xylene, 43.7 g; and toluene, 45.7 g/g oil-absorbent) when compared with that without CD (CCl4, 11.7 g; CHCl3, 13.6 g; xylene, 16.5 g; and toluene, 19.2 g/g oil-absorbent). The desorption and the reusability of the oil-absorbents were quantitatively investigated, demonstrating the absorbents can be used for at least six times. The present oil-absorbents are expected to find practical applications particularly in the recovery of spilled oils and the treatment of wastewater.