Characterization tools and techniques of hydrogels

Hydrogels are a special class of cross-linked polymeric system consisting of hydrophilic polymer chains which can be terminologically defined as “insoluble swollen solids.” Hydrogels have significantly drawn the attention of the scientific community because of their versatile exploitations in biomedical fields, cosmetic industries, water treatment, catalysis, tissue engineering, etc. However, concern over serviceability of hydrogels is manifested against their characterizations to evaluate performance, failure, and their longevity. In order to mitigate the “how and why” questions, hydrogels have been subjected to several chemical and physicomechanical experiments. As these types of materials are difficult to process either in solvent or melt conditions, it is of utmost importance to discover their morphological and microstructural attributes. In this chapter, a concise details of hydrogel characterizations are documented in order to evaluate hydrogels or gel-like hydrophilic materials.