Locust bean gum-polyvinyl alcohol hydrogels: Synthesis, characterization, swelling behaviors, and mathematical models

In this study, locust bean gum/polyvinyl alcohol (LBG/PVA) hydrogels were synthesized by the gel casting method without using toxic crosslinking agents. Infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) methods were used for characterization of the synthesized hydrogels. Scanning electron microscopy (SEM) was used for observation surface morphology of the hydrogel and swelled hydrogels. The Swelling behavior of prepared hydrogels was investigated and the data were interpreted by various kinetic models. The prepared hydrogels showed pH and temperature-responsive behavior. The maximum swelling ratio was evaluated as 607.72 at 37 degrees C. The diffusional exponent values (n) were found as 0.5946, 0.5028, and 0.2785 at 4, 25, and 37 degrees C, respectively. According to the n values, it was found that non-Fickian diffusion dominates the swelling process. The obtained diffusion prediction curves were fitted to three different models: Higuchi, Peppas, and Elmas models. Among the results, Elmas model has better fits at 277 K and 298 K while Peppas model is better at 310 K. The results indicated that LBG/PVA hydrogels could be a candidate biomaterial for drug delivery applications.