Analysis of swelling kinetics in hydrogels cross-linked by ionizing radiation for an application future in drug delivery
The Hydrogels are cross-linked polymer networks, which are of great interest in biomedical applications such as drug delivery system. To achieve successful results in this kind of application it is essential to understand the diffusion mechanisms that are generated in the hydrogel during the swelling process. For this reason, this work consists in carrying out an analysis of the swelling kinetics in hydrogels elaborate through gamma radiation and the combination of it with thermal cycling processes. We synthesize the hydrogels by irradiating the polymeric solution at different doses. Then, we used the resulting samples to make a swelling test. With the test results we calculated the swelling percentage, the diffusion coefficient and the diffusional exponent. This test showed that the higher dose used to get the gels generated the lowest swelling percentage, as well as the diffusion coefficient of the water molecules in the hydrogel. The results of the kinetic analysis, in general, showed an anomalous diffusion mechanism for the gels obtained at 25 kGy. For those gels of 30 kGy, the diffusion was Fickian. Finally, for those gels of 35 kGy was not possible to classify it according to the diffusion Fick's law. This analysis allowed us to understand the intrinsic behavior of the polymer / solvent mesh system at different doses. This is going to allow us in the future, to predict the diffusion mechanism of others molecules which could be to incorporate into the hydrogels for an application potential in the drugs delivery system.