Synthesis and swelling behavior of sodium alginate / poly (vinyl alcohol) hydrogels

INTRODUCTION: Hydrogels are macromolecular networks able to absorb and release water/biological fluids in a reverse phase manner, in response to specific environmental stimuli. Such stimuli –sensitive behavior makes hydrogels interesting for the design of smart devices applicable to a variety of technological fields. They are able to absorb and retain 10-20% and upto 1000 times of water or biological fluids than their dry weight.
METHODS: The authors are synthesized sodium alginate/poly (vinyl alcohol) hydrogels. These hydrogels are characterized by FTIR, SEM, swelling properties of hydrogels in different pH, in salts, different temperature, different acids and bases.

RESULTS: The authors studied and reported that the swelling effects or variations such as effect of salts, acids, bases, temperature and pH. The effect of cross-linking agent glutaraldehyde shows that the 8 mL glutaraldehyde has the highest swelling rate as compare to that of 10 mL and 12 mL.
DISCUSSION AND CONCLUSION: In this work authors studied the swelling degree in different acids and bases. We are concluded that the degree of swelling is decreased with increase in the concentration of the glutaraldehyde and also depending on the concentration of the acids. The swelling degree of PVA/SA hydrogels are gradually increased with increase in concentration of acids (low p H). The swelling of hydrogels decreases with increase of pH ( > 7) or at high alkaline. In the effect of salt solutions the swelling behavior is found to be in the order: K+ > Na + > Ca2+ > Mg2+.