Cyclodextrin-Functionalized Hierarchical Porous Architectures for High-Throughput Capture and Release of Organic Pollutants from Wastewater

Hydrophilic beta-cyclodextrin barrels have been tethered to a hydrophobic pulsed plasma deposited poly(4-vinylbenzyl chloride) linker layer via the Williamson ether synthesis reaction to produce an amphiphilic system that spontaneously undergoes emulsion formation to give rise to a macroporous structure. Utilization of a nonwoven polypropylene scaffold (surface area 0.52 m(2) g(-1)) yields a hierarchical 3-level porous architecture comprising beta-cyclodextrin nanopores (0.78 nm), gradient polyHIPE macroporosity (3-5 mu m), and nonwoven fibres (250 mu m spacing). These high-surface-area functional materials (672 m(2) g(-1)) are shown to readily capture probe molecules via host-guest inclusion complex formation with the surface-tethered cyclodextrin barrels. Subsequent release is accomplished by altering the pH. The repeat cycling of this capture and release behavior has been demonstrated to exceed 90% efficiency in relation to environmentally harmful water pollutant molecules commonly associated with industrial and agricultural effluents.