Adsorption studies of Cu²⁺ onto poly (vinyl alcohol)/poly (acrylamide-co-N-isopropylacrylamide) core–shell nanogels synthesized through surfactant-free emulsion polymerization

ABSTRACT

Poly (vinyl alcohol) (PVA) nanoparticle core and poly (acrylamide-co-N-isopropylacrylamide) P(AAm-co-NIPAm) hydrogel shell were fabricated to produce well-defined PVA/P(AAm-co-NIPAm) core–shell nanogels using Surfactant Free Emulsion Polymerization (SFEP). The nanogel was characterized by the FTIR, TEM TGA thermogram and SEM techniques. The adsorbent was utilized for Cu²⁺ removal from aqueous solution. Batch adsorption process indicated that 0.9 mol% PAAm nanogel exhibited higher adsorption affinity toward Cu²⁺. The kinetics parameters were investigated according to the pseudo-first-order, pseudo-second-order and intraparticle diffusion rate models. The adsorption equilibrium match with Langmuir adsorption isotherm rather than Freundlich isotherm. The Cu²⁺ loaded nanogels were effectively desorbed using 0.1 mol/l from HCl as stripping agent.

KEYWORDS:

• Acrylamide
• Cu²⁺
• nanogels adsorbent
• poly (vinyl alcohol)