Metal Nanocrystals Embedded within Polymeric Nanostructures: Effect of Polymer-Metal Compound Interactions

Abstract

pH-responsive PDEAEMA-b-PHEGMA amphiphilic block copolymers and random polymer networks have been used as matrices for the incorporation of metal species and the nucleation and growth of metal nanoparticles with sizes in the range of a few nanometers. The polymer characteristics and polymer-metal interactions upon metal incorporation and after metal reduction were investigated. Two different synthetic procedures were followed for the preparation of Pt nanoparticles within the block copolymers; addition of the metal precursor in a molecular copolymer solution at low pH led to a polymermetal charge neutralization process and the formation of micelles with compact non-hydrated cores, while the incorporation of H 2 PtCl 6 in a micellar copolymer solution at high pH led to polymer aggregation. The impregnation of K 2 PtCl 6 in a micellar copolymer solution at high pH was unsuccessful suggesting the lack of coordination of the neutral amine groups to the metal precursor. The effect of the metal precursor impregnation and the metal nanoparticle formation on the degree of swelling of random networks carrying different functionalities was also examined and the metal content of the hybrid materials was assessed. The equilibrium degrees of swelling of the networks were determined by two opposing effects: the degree of ionization, which caused the network to swell, and the polymer-metal complexation, which increased the effective cross-link density and caused the network to shrink. The metal content of the network was dictated by the polymermetal interactions and the degree of swelling of the network in the solvent medium. These hybrid materials are proposed for use as advanced catalysts in the synthesis of high-value cosmetics and pharmaceuticals.

Green synthesis of metal and metal oxide nanoparticles from plant leaf extracts and their applications: A review

“…Block copolymers are even stronger nanoparticle separation and show individual properties such as surface reactivity, flexibility, selectivity, and impedance [130]. MNPs stabilization can be fulfilled by metals in a polymer gel simple enclosure, free radical polymerization with a radical initiator [131], thiol-supported polymer adsorption [132], or in situ MNPs formation during polymerization [132][133][134].…”

pH‐sensitive polymers: Classification and some fine potential applications

“…Nanoparticle synthesis within amphiphilic block copolymer micelle cores has been explored. Indeed, these block copolymer cores used as stabilizers may act as nanoreactors for metal (especially catalytic) particle nucleation and growth with the advantages of enhancing the control of particle size and stability 267‐270 . Moreover, pH‐responsive microgel pores may also be used as templates or nanosized reactors for the synthesis of inorganic nanoparticles 271 .…”

Novel in situ electrochemical deposition of platinum nanoparticles by sinusoidal voltages on conducting polymer films

“…Noble metal nanoparticles (NP) have been incorporated in conducting polymers (CPs) using various preparation procedures [7][8][9][10]. Usually the NPs are prepared via a chemical route [11][12][13] and are then incorporated into CP layers by electrochemical polymerization of the appropriate monomer [7] or using the layer-by-layer deposition technique [14,15]. Recently, a great deal of interest has been devoted to innovative synthesis route of Pt nanoparticles, for example by the help of ultrasound [16].…”