Search results for "Ag Nanoparticle"

Incorporation of dynamic boronate links and Ag nanoparticles into PVA hydrogels for pH-Regulated and prolonged release of methotrexate

2021

Abstract In this study, pH-responsive hydrogels based on PVA-boronate crosslinks were prepared via a simple route and used for controlled and targeted delivery of anticancer drug methotrexate. A double network (DN) hydrogel composed of didiol-boronate/PVA complex as the first network and PVA crystallites generated by a freeze-thaw process as the second one was developed. The swelling of PVA-boronate DN hydrogels demonstrated high sensitivity to multiple stimuli including the pH, temperature, and ionic strength of the media thanks to the dynamic boronate links in the first network. Moreover, unlike previously reported hydrogels based on the boronate linkages, the new DN hydrogels preserved t…

Synthesis of yttrium aluminum garnet nanoparticles in confined environment III: Cerium doping effect

2018

Abstract Cerium yttrium aluminum garnet (Ce:YAG, CexY3-xAl5O12) nanoparticles doped with different cerium amount were obtained by calcining the precursors synthesized via co-precipitation in w/o microemulsion for 1 h at 900 °C. The structural and morphological properties were investigated by using X-ray Diffraction (XRD), Infrared Spectroscopy (IR) and Transmission Electron Microscopy (TEM) coupled with Energy Dispersive X-ray Spectroscopy (EDS) in order to investigate the effect of doping level on formation and microstructure of obtained nanoparticles. It was found that the composition of the final products strongly depends on the concentration of cerium. The formation of single YAG phase …

Fabrication of silver nanoparticles by a diethylene triamine-hyaluronic acid derivative and use as antibacterial coating

2022

In this work a synthetic protocol for the functionalization of hyaluronic acid with diethylenetriamine (DETA) was standardized. HA-DETA derivatives were characterized by NMR and proton carbon correlation analysis HSQC and HMBC to confirm chemical structure. A selected derivative was used to set up a green fabrication procedure for HA-DETA capped silver nanoparticles with the aim to achieve a polymeric based coating with potential application in the treatment of medical devices associated infections. Data from UV-visible spectroscopy, electron scanning and transmission microscope (STEM), photoelectric spectroscopy (XPS) and rheological characterization were combined to characterize the HA-DE…

System Design Rules for Intensifying the Electrochemical Reduction of CO 2 to CO on Ag Nanoparticles

2020

Electroreduction of CO2 (eCO2RR) is a potentially sustainable approach for carbon-based chemical production. Despite significant progress, performing eCO2RR economically at scale is challenging. Here we report meeting key technoeconomic benchmarks simultaneously through electrolyte engineering and process optimization. A systematic flow electrolysis study - performing eCO2RR to CO on Ag nanoparticles as a function of electrolyte composition (cations, anions), electrolyte concentration, electrolyte flow rate, cathode catalyst loading, and CO2 flow rate - resulted in partial current densities of 417 and 866 mA/cm2 with faradaic efficiencies of 100 and 98 % at cell potentials of −2.5 and −3.0 …

One pot light assisted green synthesis, storage and antimicrobial activity of dextran stabilized silver nanoparticles.

2014

Background Green synthesis of nanomaterials finds the edge over chemical methods due to its environmental compatibility. Herein, we report green synthesis of silver nanoparticles (Ag NPs) mediated with dextran. Dextran was used as a stabilizer and capping agent to synthesize Ag NPs using silver nitrate (AgNO3) under diffused sunlight conditions. Results UV–vis spectra of as synthesized Ag nanoparticles showed characteristic surface plasmon band in the range from ~405-452 nm. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies showed spherical Ag NPs in the size regime of ~50-70 nm. Face centered cubic lattice of Ag NPs was confirmed by powder X-ray diffraction (PXRD…

Cover Feature: System Design Rules for Intensifying the Electrochemical Reduction of CO 2 to CO on Ag Nanoparticles (ChemElectroChem 9/2020)

2020

Synthesis of yttrium aluminum garnet nanoparticles in confined environment II: Role of the thermal treatment on the composition and microstructural e…

2017

Abstract Nanoparticles of yttrium aluminum garnet (YAG, Y 3 Al 5 O 12 ) have been obtained by thermal treatments, at several temperature in the range 400–950 °C, of the precursors synthetized via co-precipitation in water in oil microemulsion. The obtained nanoparticles have been characterized by means of X-ray Diffraction and Transmission Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy (EDS) and Select Area Electron Diffraction (SAED). Results show the phase evolution occurring to obtain not aggregated nanoparticles of YAG phase. A possible growth mechanism of YAG nanoparticles is discussed on the basis of observed particle microstructure and morphology. The results i…

Composite Coatings of Chitosan and Silver Nanoparticles Obtained by Galvanic Deposition for Orthopedic Implants

2022

In this work, composite coatings of chitosan and silver nanoparticles were presented as an antibacterial coating for orthopedic implants. Coatings were deposited on AISI 304L using the galvanic deposition method. In galvanic deposition, the difference of the electrochemical redox potential between two metals (the substrate and a sacrificial anode) has the pivotal role in the process. In the coupling of these two metals a spontaneous redox reaction occurs and thus no external power supply is necessary. Using this process, a uniform deposition on the exposed area and a good adherence of the composite coating on the metallic substrate were achieved. Physical-chemical characterizations were car…

Impact of Ag and Co engineered nanoparticles on soil microbial community structure in a soil perturbed by Lumbricus rubellus

2014

Knowledge on the impact of engineered nanomaterials (ENMs) on both human and environment health is scarce. Several studies sustain that soil is the environmental compartment designed to be the major recipient of engineered nanoparticles (NPs). With the aim of investigating the impact of commercially relevant NPs on soil functioning, we compared the effect of Ag and Co NPs, as well as cobalt and silver ions, on soil microbial community in the presence of Lumbricus rubellus. Earthworms specimens were placed in a rich‐C soil and fed with horse manure spiked with Ag‐NPs, Co‐NPs, Ag+ and Co2+ for a total amount of 10 mg of single pollutant kg‐1 soil. At the end of acute exposure (4 weeks) to pol…