Abstract:
Bio-based hydrogels (denoted as PC-PAAc/GA) comprised of Pectin (PC) and polyacrylic acid (PAAc) reinforced with dif-
ferent ratios of gallic acid (GA) were prepared by gamma radiation at irradiation dose 20 kGy. The prepared hydrogels were
investigated by diferent analytical tools. The swelling performance was studied versus time, pH of the medium and gallic
acid content. The experimental data depicted that the swelling increases with pH of medium until the equilibrium of swelling
after 350 min. The maximum swelling was attained at pH10 for both PC-PAAc and PC-PAA/GA1.5. Also, the data reveal
that the incorporation of GA in the hydrogel matrix enhanced the swelling performance of the hydrogel up to an optimum
value of GA, i.e. PC-PAA/GA1.5. Further increase in GA concentration leads to formation of a highly crosslinked structure
with reduced swelling. The results demonstrated that the prepared hydrogels displayed excellent antibacterial activity against
gram+ve bacteria (E.coli) and gram-ve bacteria (S.aureus). This potent antimicrobial activity is mainly originated from GA
which was proved as a strong antibacterial agent. Moreover, the removal performance of the investigated hydrogels was veri-
fed towards Pb+2 cation as one of the most poisonous heavy metals. The data revealed that the maximum removal percent-
age of Pb (II) was attained by PC-PAAc/GA1.5 hydrogel (90 mg g−1). The correlation coefcients of the Langmuir model
are too higher than that of the Freundlich model that assumed the adsorption of lead cations is mainly a chemical process.
