Evaluation of adsorption and biological activities of polyaniline-grafted-pectin as conductive nanogels

Nanogel composites based on hydrolyzed pectin-grafted-polyaniline (HPEc-g-PANi) (GCP) were synthesized via chemical polymerization method and characterized via different analyses including FTIR, 1HNMR, UV-Vis, Raman, XRD, SEM, AFM, TGA, DSC and DMTA. Swelling, electrical conductivity and zeta potential studies were performed to evaluate physicochemical properties. The adsorption studies on GCP for different metal ions of Pb+2, Cu+2, Ni+2 and Cd+2 showed selectivity of GCP toward Pb+2 and high removal efficiency up to 90% by 0.03 g adsorbent for 2 h at pH:5. For determination of hydrophilicity, contact angle measurements were done on PANi and copolymers. HPEc-g-PANi (2:1) copolymer showed more hydrophobicity feature due to lower polar PANi sites which reduces water absorption. Antibacterial analyses demonstrated a desirable inhibition zone of the copolymers and specially PANi. Among copolymers, HPEc-g-PANi (2:1) due to more hydrophobicity represented better antibacterial activity than others. This conclusion support influence of hydrophobicity on antibacterial activity. HPEc macromolecules help to the entrance of PANi chains into bacteria cell wall and destruction of cell cytoplasm. Anticancer experiments indicated an efficient toxicity effect on cancer cells up to 56% reduction in cell viability percentage. Antioxidant test indicated an efficiency inhibition of GCP to free radicals up to a maximum absorption of 80%.