The study of factors affecting the swelling of ultrasound-prepared hydrogel

Gel is a porous continuous 3D network that contains a liquid phase. In most sol–gel systems, the formation of gel is accompanied by the creation of covalent bonds and this formation is irreversible. This study has been done to use a new, fast and bioenvironmental method for synthesis of acrylic hydrogels in the presence of ultrasound and to investigate the effect of different initial conditions of synthesis on swelling and on the structure of the resulting hydrogels. This method does not require any heat and initiator, the reaction is fast, and the gel polymer has a uniform structure with a high swelling capacity. SEM images of samples showed uniform nanostructures with high fine pores. The factors affecting the gel formation were changed during the gel synthesis process to determine its impact on the reaction time and the swelling of the obtained gel. As the power of ultrasound increased, the reaction time shortened and gel swelling and its porosity increased. This happened because of more sonic cavitation and consequently more radical production. The solvent viscosity had similar effects on reaction time and gel swelling. The results of this research can be used in various industries such as pharmaceutics, cosmetics, health, medicine, agriculture and biotechnology in which the swelling properties of superabsorbent hydrogels are used. Also, due to pH-sensitivity and biodegradability, the present hydrogels can be used as a carrier for oral drugs.