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.
Biography:
Dr. Lee D. Wilson (PhD) is an Associate professor in the department of chemistry at the University of Saskatchewan with research interests in physical chemistry and macromolecular systems in aqueous media. Wilson’s research is in the area of Physical Chemistry, Materials & Environmental Science where current efforts are being directed at the development of new types of macromolecular materials and their structure-function relationships that relate to adsorption phenomena. Modified biopolymer materials will have a tremendous impact on areas such as green catalysis, aquatic environments, biotechnology, medicine, chemical delivery/separation systems, and sorbent materials for water purification.
