Title : Tuning the Surface Adsorption Properties of Polymer Sorbents via Facile Methods
Abstract:
Cross-linked polymers were prepared by coupling β-cyclodextrin (β-CD) with two different types of diisocyanates, respectively. Materials with diverse structural and textural properties were obtained by varying the rate of diisocyanate addition: rapid (R) or drop-wise (D; 0.1 mL/min). Characterization of the structural and textural properties was investigated by spectroscopic (1H NMR in solution, solid state 13C CP-MAS solids NMR, dynamic light scattering, UV-vis, and IR), thermogravimetric analysis, powder x-ray diffraction, and scanning electron microscopy. The accessibility of the β-CD inclusion sites of the polymers was independently evaluated using an equilibrium dye adsorption method at equilibrium and in parallel with a kinetic dye-based uptake method. The characterization methods strong support that drop-wise additions affords materials with greater cross-linking relative to the rapid addition method. Herein, we report a first example of such cross-linked polymers with tunable structure and physicochemical properties, according to the mode of cross-linker addition (R versus D) to control the reaction conditions. The resulting physicochemical properties of these polymers are shown to play a significant role in catalytic transformations and controlled-release carrier systems.
