Synthesis of amphiphilic polymer networks with guest‐host properties

Abstract

A modular assembly procedure for producing amphiphilic polymer networks containing specific linker lengths between cyclodextrin (CD) cross-link sites is described. The linker type and length can be selected to tune the relative hydrophilicity/hydrophobicity of the network, and the size of the guest-host binding site can be varied by using either a-, b-, or c-CD as the node. The two-step, one-pot reaction sequence produces well-defined networks with stable ether linkages that can be purified by simple washing and filtration steps. Short ethylene glycol versus long polyethylene oxide linkers result in networks that are generally insoluble in common organic solvents, but which swell to varying degrees in polar protic, polar aprotic, and chlorinated solvents such as water, methanol, ethanol, dimethylsulfoxide, dimethylformamide, methylene chloride, and chloroform. All networks swell in water and present a hydrophobic CD cavity that is available for binding nonpolar molecules. The networks should be applicable to the removal of hydrophobic contaminants, for example, pharmaceutical molecules, from water or wastewater streams.

Functional Supramolecular Polymeric Networks: The Marriage of Covalent Polymers and Macrocycle-Based Host–Guest Interactions

“…Polymeric hydrogels are an important class of water-containing soft materials. They have seen use in a variety of biomedical and industrial applications due to their easily varied mechanical properties and generally good biocompatibility. − Supramolecular hydrogels or non-covalently cross-linked hydrophilic polymer networks based on specific non-covalent and dynamic binding motifs are a subset of polymeric hydrogels that have attracted considerable attention in recent years. ,, Liu and co-workers reported a supramolecular cross-linked hydrogel with a three-dimensional network structure ( 149 ) based on an amphiphilic sulfonato­calix[4]­arene, 147 , and a MV 2+ -containing poly­(vinyl alcohol) 148 . As shown in Figure , hydrogel 149 can be considered as being produced as the result of (i) initial self-assembly of 147 followed by (ii) host–guest driven secondary assembly of the resulting micelles with 148 .…”