Surface functionalized cryogels – Characterization methods, recent progress in preparation and application

Abstract

Cryogels are polymeric materials possessing a sponge-like microstructure and have attracted significant attention within the last decades. A variety of publications are comprising their composition, fabrication techniques, characterization methods as well as potential or existing fields of applications. The use of e.g. functional precursors or functionalizing ligands enables the preparation of cryogels with desired properties such as biocompatibility or responsivity. They can also possess adsorptive properties or can be used for catalytical purposes. Although several functional (macro-)monomers and functionalizing ligands have been reported in previous reviews for certain cryogel applications, so far there was no particular focus on the evaluation of the functionalization success and the used characterization methods. This review will provide a comprehensive overview about different characterization methods most recently used for the evaluation of cryogel functionalization. Furthermore, new functional (macro-)monomers and subsequent cryogel functionalization strategies are discussed, based on synthetic polymers, biopolymers and a combination of both. This review highlights the importance of the functionalization aspect in cryogel research in order to produce materials with tailored properties for certain applications.