Phenolic Pollutant Uptake Properties of Molecular Templated Polymers Containing β-Cyclodextrin

Abstract

Templated (T) and nontemplated (NT) cross-linked materials containing β-cyclodextrin (β-CD) and epichlorohydrin (EPH) were prepared at variable β-CD-EPH ratios (1:15, 1:20, and 1:25) in the presence and absence of a molecular template (toluene). The structural characterization of the materials was carried out using spectroscopy (Fourier transform infrared, solids C NMR, and scanning electron microscopy) and thermogravimetric analysis. The adsorption properties were studied with phenol-based adsorbates (2,4,6-trinitrophenol (TNP) and p-nitrophenol (PNP)) at equilibrium and dynamic conditions. The monolayer adsorption capacity ( Q) varied for the T-polymer/TNP systems ( Q = 0.10-0.95 mmol/g) and NT-polymer/TNP systems ( Q = 0.23-0.83 mmol/g). The range of Q values for the T-polymer/PNP systems (0.26-0.62 mmol/g) exceeded that of the NT-polymer/PNP systems (0.23-0.40 mmol/g). The kinetic uptake profiles for the polymers and phenolphthalein were reliably described by the pseudo-first-order model. The β-CD inclusion site accessibility for the polymers varied from 15 to 20%, according to the level of cross-linking, where the accessibility of the T-polymers exceeded that of the NT-polymers. The structural characterization and phenol adsorption properties provide complementary support for the role of tunable polymer morphology in adsorption processes. The role of two-site binding was demonstrated for linear and globular polymer materials according to their unique adsorption properties with phenols of variable size and hydrophile-lipophile character.

Study on Preparation and Separation and Adsorption Performance of Knitted Tube Composite β-Cyclodextrin/Chitosan Porous Membrane

“…The Double constant equation is a dynamic empirical formula suitable for characterizing the complex reaction process. The Elovich equation is also an empirical formula to explain the adsorption process of adsorbents on irregular surfaces with a large number of active adsorption sites, and to illuminate non-ideal adsorption state [38,39,40,41]. The experimental data were fitted to the Pseudo-first-order kinetic model (Equation (9)), the Pseudo-second-order kinetic model (Equation (10)), the Double constant kinetic model (Equation (11)), and the Elovich kinetic model (Equation (12)).…”

A porous β-cyclodextrin-based terpolymer fluorescence sensor for in situ trinitrophenol detection

“…A recent study has shown that nitrophenols with variable hydrophile-lipophile balance (HLB) can be adsorbed at inclusion versus interstitial domains of epichlorohydrin cross-linked materials that contain b-CD. 51 This can be understood since the interstitial domains that contain epichlorohydrin may possess greater hydrophile character over urethane linkages that contain lipophile cross-linker units such as TPE. As well, polysaccharide materials undergo solvent swelling in water, where judicious selection of adsorbate such as nitroarenes 42 with variable electron deciency can provide insight on the structural characterization and the uorescence quenching mechanism, as described below.…”

Surface-Modified Chitosan: An Adsorption Study of a “Tweezer-Like” Biopolymer with Fluorescein

“…The kinetic uptake profile of FL against time with CS-Ac-An was obtained using a one-pot kinetic method [78]. The results of the kinetic study at 23 • C are shown in Figure 7, where the adsorption capacity (Q t ) increased in the first 60 min and remained constant thereafter.…”