A Green Route to Copper Loaded Silica Nanoparticles Using Hyperbranched Poly(Ethylene Imine) as a Biomimetic Template: Application in Heterogeneous Catalysis

Abstract

Abstract:Copper containing silica nanostructures are easily produced through a low cost versatile approach by means of hyperbranched polyethyleneimine (PEI), a water soluble dendritic polymer. This dendritic molecule enables the formation of hybrid organic/inorganic silica nanoparticles in buffered aqueous media, at room temperature and neutral pH, through a biomimetic silicification process. Furthermore, the derived hybrid organic/inorganic materials dispersed in water can be easily loaded with various copper amounts, due to the presence of PEI, which, despite having been integrated in the silica network, retains its strong copper chelating ability. Following calcination, the obtained copper loaded nanopowders are characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), N 2 adsorption, Temperature programmed reduction (TPR) and UV-Vis diffuse reflectance (UV-Vis-DR) techniques and evaluated for automotive exhaust purification under simulated conditions at the stoichiometric point. Effective control over final materials' pore structural and morphological characteristics is provided by employing different buffer solutions, i.e., tris(hydroxymethyl)aminomethane (Tris) or phosphate buffer. It was found that the enhancement of the nanopowders textural features, obtained in the presence of Tris buffer, had a great impact on the material's catalytic behavior, improving significantly its activity towards pollutants oxidation.

Comparative Study of the U(VI) Adsorption by Hybrid Silica-Hyperbranched Poly(ethylene imine) Nanoparticles and Xerogels

“…In some of the most important implementations, the hyperbranched polymers are combined with inorganic substrates [85]. Examples of this category include (photo)catalysts [86][87][88], implants [89], and most notably, water purification [90][91][92]. In this context, our group has developed biomimetic silica-hyperbranched poly(ethylene imine) (PEI) nanospheres that proved capable of adsorbing a variety of pollutants [93].…”

Preparation and Study of the Antibacterial Applications and Oxidative Stress Induction of Copper Maleamate-Functionalized Mesoporous Silica Nanoparticles

“…Finally, bearing in mind that some of the current studies in biomedicine are focused on the potential use of the catalytic properties of some made-to-measure catalytic metallodrugs, which are able to improve the therapeutic effects in different diseases through their catalytic reactivity [44,45,46,47,48]; and that some copper species have already been supported onto MSNs showing interesting biological and/or catalytic properties [49,50,51,52], we have evaluated the potential influence of the catalytic selective oxidation properties of the studied materials in the induction of oxidative stress in bacteria. We have tested the synthesized nanomaterials as oxidation catalysts in “solvent free” oxidation reactions, to try to determine if there is a potential correlation between the catalytic oxidation capacity of the materials in regular organic reactions and the observed oxidative stress in bacteria.…”

Dendritic Polymers as Promising Additives for the Manufacturing of Hybrid Organoceramic Nanocomposites with Ameliorated Properties Suitable for an Extensive Diversity of Applications

“…Moreover, these metal organoceramic nanocomposites are noteworthy candidates for catalysis reactions [ 171 , 172 , 173 ] ( Table 2 ). They are particularly useful when gas phases are involved in reactions such as low molecular hydrocarbon hydrogenation and epoxidation.…”