Free radical synthesis of nanosilver/gelatin-poly (acrylic acid) nanocomposite hydrogels employed for antibacterial activity and removal of Cu(II) metal ions

Abstract

The present work involves the synthesis of porous gelatin/AcA (PGE-AcA) hydrogel and novel porous gelatin-silver/AcA (NPGESNC-AcA) nanocomposite hydrogel, and their ability as effective biosorbents for the removal of Cu²⁺ ions from contaminated water. The formation of the samples was confirmed by UV-Vis, TEM, SEM, EDX, DLS, AFM, XRD, TGA/DTG and FTIR techniques. The adsorption studies results showed that maximum monolayer adsorption capacity of copper ions for PGE-AcA was achieved about 130.50 mg g^-1 in pH 6.0 for 50 min, and adsorption capacity for the NPGESNC-AcA was nearly 147.10 mg g^-1 in pH 5.5 for 40 min by atomic absorption spectroscopy technique. The Cu²⁺ ions loaded on the PGE-AcA and NPGESNC-AcA could be recovered by HCl above 65.8% and 78.7% after five consecutive cycles of adsorption/desorption, respectively. The results showed that the both of biosorbents loaded by Cu²⁺ ions could be easily regenerated and reusable. On the other hand, the results of adsorption kinetics and equilibrium isotherms were indicated high correlation coefficient (closer to a unit) for the pseudo-second-order and excellent fitted the adsorption data with the Langmuir isotherm model. Furthermore, the antimicrobial efficiency of the synthesized samples were tested on the Staphylococcus aureus and the Escherichia coli.

Keywords: AgNPs; Antibacterial activity; Biosorbent; Cu(2+) Ions; Gelatin.