Silica Meets Tannic Acid: Designing Green Nanoplatforms for Environment Preservation
Fabiana Tescione,
Olimpia Tammaro,
Aurelio Bifulco,
Giovanni Del Monaco,
Serena Esposito,
Michele Pansini,
Brigida Silvestri,
Aniello Costantini
Affiliations
Fabiana Tescione
Institute for Polymers, Composites and Biomaterials of National Research Council (IPCB-CNR), P.le Enrico Fermi 1, 80055 Portici, Italy
Olimpia Tammaro
Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
Aurelio Bifulco
Department of Chemical, Materials and Production Engineering (DICMaPI), University of Naples Federico II, P.le Tecchio 80, 80125 Naples, Italy
Giovanni Del Monaco
Provincial Department of Caserta, Regional Agency for Environmental Protection of Campania (ARPAC), Via Arena-Centro Direzionale (San Benedetto), 81100 Caserta, Italy
Serena Esposito
Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
Michele Pansini
Civil and Mechanical Engineering and INSTM Unit, University of Cassino and Southern Lazio, Via G. Di Biasio 43, 03043 Cassino, Italy
Brigida Silvestri
Department of Chemical, Materials and Production Engineering (DICMaPI), University of Naples Federico II, P.le Tecchio 80, 80125 Naples, Italy
Aniello Costantini
Department of Chemical, Materials and Production Engineering (DICMaPI), University of Naples Federico II, P.le Tecchio 80, 80125 Naples, Italy
Hybrid tannic acid-silica-based porous nanoparticles, TA-SiO2 NPs, have been synthesized under mild conditions in the presence of green and renewable tannic acid biopolymer, a glycoside polymer of gallic acid present in a large part of plants. Tannic acid (TA) was exploited as both a structuring directing agent and green chelating site for heavy metal ions recovery from aqueous solutions. Particles morphologies and porosity were easily tuned by varying the TA initial amount. The sample produced with the largest TA amount showed a specific surface area an order of magnitude larger than silica nanoparticles. The adsorption performance was investigated by using TA-SiO2 NPs as adsorbents for copper (II) ions from an aqueous solution. The effects of the initial Cu2+ ions concentration and the pH values on the adsorption capability were also investigated. The resulting TA-SiO2 NPs exhibited a different adsorption behaviour towards Cu2+, which was demonstrated through different tests. The largest adsorption (i.e., ~50 wt% of the initial Cu2+ amount) was obtained with the more porous nanoplatforms bearing a higher final TA content. The TA-nanoplatforms, stable in pH value around neutral conditions, can be easily produced and their use would well comply with a green strategy to reduce wastewater pollution.
