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

Hydrophilic β-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 0.5 m 2 g –1 ) yields a hierarchical 3-level porous architecture comprising β-cyclodextrin nanopores (0.78 nm), gradient polyHIPE macroporosity (3 – 5 μm), and nonwoven fibres (250 μm 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.