Nanostructured polymer composites for selective heavy metal ion sorption

The modification of silica microparticles surface with a high number of amino/carboxylic groups of polymer chains represent an interesting route to obtain nanostructured composite materials aiming different applications. Herein, four weak polycations (PC) [polyethyleneimine (PEI), polylysine (PLL), polyvinylamine (PVAm), poly-allylamine hydrochloride (PAH)] and one weak polyanion [polyacrylic acid (PAA)] were layer-by-layer de-posited onto spherical silica to form composite microparticles. A strategy where each deposited polycation layer was chemically cross-linked with glutaraldehyde (GA) prior to the deposition of PAA layer was used, forming at the end silica//(PCeGA/PAA)n composite microparticles. Finally, we investigated the particles towards their adsorption properties on metal ions (Cu2+, Pb2+, Ni2+, and Fe2+) from simulated and real surface water, as a potential application for the composite particles.