Grafting of cyclodextrins onto polypropylene nonwoven fabrics for the manufacture of reactive filters. III. Study of the sorption properties

Abstract

AbstractPolypropylene nonwoven supports carrying α‐, β‐, and γ‐cyclodextrins (CDs) were synthezised. The synthesis consisted of grafting glycidyl methacrylate (GMA) onto the fibers and reacting CDs with epoxide groups in the second step. This article concerns the sorption capacity of these supports toward organic pollutant models of 2‐naphtol, 4‐nitrophenol, pentachlorophenol, and (2,4‐dichlorophenoxy) acetic acid in static (batch) or dynamic (filtration) conditions. The results confirmed that the grafting of CDs onto the supports gave them their specific sorption properties. Besides, it was observed that the best performances were attained when the GMA add‐on was in the range of 76–113 % wt and the CD content was 87–118 μmol/g. We also evidenced that the interactions between the organic substrates and the filter occurred through specific interactions with CDs (host–guest inclusion compounds) and that to a lesser extent, nonspecific sorption phenomena also occurred. The data showed that the affinity between the pollutants with three different grafted CDs was not in agreement with the complex formation constants measured in homogeneous systems. Furthermore, the slow kinetics of exchange between the liquid and solid phases was a limiting factor that should prevent the use of the filters at elevated flow rates. At last, the great advantage of these filters is that they could undergo several cycles of use, thanks to intermediate regeneration steps with water–organic solvent mixtures. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1771–1778, 2002