Polymer-stabilized palladium nanoparticles for catalytic membranes: ad hoc polymer fabrication

Metal nanoparticles are known as highly effective catalysts although their immobilization on solid supports is frequently required to prevent aggregation and to facilitate the catalyst application, recovery, and reuse. This paper reports the intermatrix synthesis of Pd0 nanoparticles in sulfonated polyethersulfone with Cardo group membranes and their use as nanocomposite catalytic membrane reactors. The synthesized polymer and the corresponding nanocomposite were characterized by spectroscopic and microscopic techniques. The catalytic efficiency of catalytic membranes was evaluated by following the reduction of p-nitrophenol in the presence of NaBH4

Morphological changes of gel-type functional polymers after intermatrix synthesis of polymer stabilized silver nanoparticles

This paper reports the results of intermatrix synthesis (IMS) of silver metal nanoparticles (Ag-MNPs) in Purolite C100E sulfonic ion exchange polymer of the gel-type structure. It has been shown that the surface morphology of the initial MNP-free polymer is absolutely smooth, but it dramatically changes after the kinetic loading of Ag on the polymer and then IMS of Ag-MNPs. These morphological changes can be explained by the interaction of Ag-NPs with the polymer chains, leading to a sort of additional cross-linking of the polymer. As a result, the modification of the gel-type matrix with Ag-MNPs leads to the increase of the matrix cross-linking, which results in the increase of its surface area and the appearance of nanoporosity in the polymer gel. Ag-MNPs are located near the polymer surface and do not form any visible agglomerations. All these features of the nanocomposites obtained are important for their practical applications in catalysis, sensor applications, and bactericide water treatme

Bifunctional Polymer-Metal Nanocomposite Ion Exchange Materials

Peer ReviewedPostprint (published version

Development of novel catalytically active polymer-metal-nanocomposites based on activated foams and textile fibers

In this paper, we report the intermatrix synthesis of Ag nanoparticles in different polymeric matrices such as polyurethane foams and polyacrylonitrile or polyamide fibers. To apply this technique, the polymer must bear functional groups able to bind and retain the nanoparticle ion precursors while ions should diffuse through the matrix. Taking into account the nature of some of the chosen matrices, it was essential to try to activate the support material to obtain an acceptable value of ion exchange capacity. To evaluate the catalytic activity of the developed nanocomposites, a model catalytic reaction was carried out in batch experiments: the reduction of pnitrophenol by sodium borohydridePostprint (published version

Intermatrix synthesis: easy technique permitting preparation of polymer-stabilized nanoparticles with desired composition and structure

The synthesis of polymer-stabilized nanoparticles (PSNPs) can be successfully carried out using intermatrix synthesis (IMS) technique, which consists in sequential loading of the functional groups of a polymer with the desired metal ions followed by nanoparticles (NPs) formation stage. After each metal-loading-NPs-formation cycle, the functional groups of the polymer appear to be regenerated. This allows for repeating the cycles to increase the NPs content or to obtain NPs with different structures and compositions (e.g. core-shell or core-sandwich). This article reports the results on the further development of the IMS technique. The formation of NPs has been shown to proceed by not only the metal reduction reaction (e.g. Cu0-NPs) but also by the precipitation reaction resulting in the IMS of PSNPs of metal salts (e.g. CuS-NPs)

Ecologically Friendly Polymer-Metal and Polymer-Metal Oxide Nanocomposites for Complex Water Treatment

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Polyurethane foams doped with stable silver nanoparticles as bactericidal and catalytic materials for the effective treatment of water

The development of reusable dual-purpose nanocomposite foams for catalytic and bactericidal water treatment is reported. Small non-aggregated silver nanoparticles were made using Intermatrix Synthesis inside a polyurethane foam, which was chosen as a suitable polymeric matrix due to its high chemical and mechanical stability and industrial applicability. The antibacterial activity of the obtained nanocomposites was evaluated against suspensions of Gram-negative bacteria (E. coli), showing ideal bactericidal features for being applied to water disinfection. The catalytic activity of nanocomposites was also evaluated through a model reaction carried out under flow conditions. The possibility of reusing the catalytic material was evaluated in 3 consecutive cycles and, for all of them, no significant loss of efficiency was found. Moreover, the leakage of the active species to the media was evaluated under accelerated ageing conditions (3 h in an ultrasonic bath) and a negligible amount of silver was found outside the matrix. The chemical stability of the as-prepared nanoparticles was also evaluated by XANES and any modification in the chemical structure of silver nanoparticles was detected, even after storing the samples for two years under dry conditionsPostprint (published version

Novel routes for inter-matrix synthesis and characterization of polymer stabilized metal nanoparticles for molecular recognition devices

10 pages, 7 figures, 1 table.-- Printed version published Oct 25, 2006.-- Issue title: "Eurosensors XIX - The 19th European Conference on Solid-State Transducers"This paper reports the results obtained by development of novel approaches for inter-matrix synthesis and characterization of polymer stabilized metal nanoparticle (PSMNP), which can be applied in molecular recognition devices (MRD) such as, sensors and biosensors. The proposed approaches are based on the use of functionalized polymeric membranes as a nanoreactor for both synthesis and characterization of PSMNP. The desired functionalization is achieved by either chemical grafting of functional groups to the polymeric matrix or by using physical immobilization of the metal-selective extractants inside the polymer by using solid-phase-incorporated-reagents (SPHINER) technique. In both cases the functional groups of either extractant or functional polymer are able to chemically fix metal ions or complexes inside the parent polymeric matrix prior to their reduction and formation of PSMNP. The results obtained by the inter-matrix synthesis and characterization of Pt- and Cu-PSMNP in polymeric membranes and on the use of these polymer-metal nanocomposite membranes as sensing elements in modified graphite-epoxy composite electrodes are reported and discussed.This work was supported by research grant BIO2003-06087 from the Ministry of Science and Technology of Spain, which is also acknowledge for the financial support of Dmitri N. Muraviev within the Program Ramon y Cajal. The Microscopy Service of the Autonomous University of Barcelona is acknowledged for their assistance.Peer reviewe

Experimental investigation of the effect of annular flow on the lateral vibration of a flexible rotor

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