Synthesis of gum acacia-silver nanoparticles based hydrogel composites and their comparative anti-bacterial activity

An interpenetrating polymer network (IPN) containing gum acacia (GA), poly(methacrylic acid) (MAA), and poly(acrylic acid) (AA) was developed using a two-step aqueous polymerization method. Firstly, semi-IPNs were produced by radical polymerization of MAA chains onto GA in the presence of ammonium persulfate as a free radical initiator and N, N '-methylene-bisacrylamide (MBA) as a cross-linking agent using a microwave heating. To obtain a semi-IPN with a higher swelling percentage, several reaction parameters such as initiator, monomer, and crosslinker concentrations were varied. The percentage swelling (%S) was highly dependent upon the reaction conditions. The optimal reaction conditions for maximal %S were 2.55 x 10(-2) mol/L initiator concentration, 12 mL solvent, 0.424 x 10(-3) mol/L of monomer, and 2.16 x 10(-2) mol/L cross-linker concentration, according to the findings. GA-g-poly(MAA) was the name to given to the semi-IPN. Second, IPN was created by grafting AA chains onto a GA-g-poly(MAA) matrix that had been optimized. The IPN was named as a GA-g-poly(MAA-IPN-AA). The reduction of silver ions to silver nanoparticles (AgNPs) was carried out by heating the mixture of flower extract of Koelreuteria apiculate under microwave radiation. Finally, the as-prepared semi-IPN and IPN samples were used as templates for the loading of AgNPs. XRD, FTIR, SEM, and TGA were used to characterize the synthesized semi-IPN, IPN, and their composites with AgNPs. GA, GA-g-poly(MAA), GA-g-poly(MAA-IPN-AA), and their composites with AgNPs are tested for antibacterial activity against five common bacteria strains: Escherichia coli, Micrococcus luteus, Pseudomonas aeruginosa, Rhizobium species, and Staphylococcus aureus. All of the bacteria strains were shown to have a noticeable zone of inhibition when IPN and their composite with AgNPs were used. When compared to other bacteria strains, Pseudomonas aeruginosa was observed to be more vulnerable to the tested samples. The obtained results demonstrate that the synthesized systems are suitable for application as antibacterial agents.