Preparation and characterization of carboxymethyl chitosan hydrogel

Purpose The purpose of the study reported in this paper was to investigate the process for the preparation of carboxymethyl chitosan (CMCS) hydrogel and to characterize such a hydrogel via various analytical techniques. Design/methodology/approach The hydrogel in the aqueous solution was prepared by using CMCS as the raw material and glutaraldehyde as the crosslinking agent. The as-prepared CMCS hydrogel was characterized by transmission electron microscopy, scanning electron microscopy, Fourier transform infrared (FTIR) spectra, differential scanning calorimetry, X-ray diffraction (XRD) and ultraviolet-visible (UV-vis) spectra. Findings The CMCS hydrogel possessed a porous structure and the shape of the pore was irregular. Generally, the diameter of the pores ranged from 20 to 70 nm. The results from FTIR, UV-vis and XRD showed that there was no obvious difference between the structures of the CMCS hydrogel and CMCS powder. Research limitations/implications The strength of the hydrogel is not high enough and the degree of swelling is relatively small. So, improving the strength and swelling degree of the hydrogel is necessary. Practical implications The CMCS hydrogel presented obvious hollow structures and its fabrication was processed absolutely in aqueous phase. Besides, it possessed low toxicity, good biocompatibility and biodegradability. So, the hydrogel will have potential applications in drug delivery and release, tissue engineering and other biomedical fields. Originality/value This paper is the first to present the relationship between the structures of the CMCS hydrogel and CMCS micromolecule, and it confirms that there is no fundamental difference between them.