Search results for "NANOCOMPOSITE"
showing 10 items of 641 documents
Exploring corrosion protection properties of alkyd@lanthanide bis-phthalocyanine nanocomposite coatings
2017
Organic coatings have been widely used to protect carbon steel pipelines from external corrosion; however, they often suffer from permeability and weak adhesion. Here we show that synthetic lanthanide bis-phthalocyanine complexes, LnPc2 (Ln = lanthanide metal, Pc = C32H16N8 denotes the phthalocyanine ligand) can be used to form new nanocomposite coatings to provide corrosion protection to the underlying carbon steel pipelines. Electrochemical studies (EIS and potentiodynamic polarization) showed that the incorporation of LnPc2 compound (PrPc2, SmPc2 and HoPc2) additives with alkyd coating, leads to a significant increase in the corrosion resistance of carbon steel in 0.5 M HCl solution. The…
Optimal degradation of Ciprofloxacin in a heterogeneous Fenton-like process using (δ-FeOOH)/MWCNTs nanocomposite
2021
Abstract This study was aimed at the synthesis and characterization of ( δ -FeOOH)/MWCNTs nanocomposite as the catalyst for Ciprofloxacin (CIP) removal through a heterogeneous Fenton-like process. The proposed experimental design applies the central composite design (CCD) as a response surface methodology (RSM). The effect of influential parameters, including initial CIP concentration, catalyst dose, H 2 O2 concentration, initial pH, and reaction time on removal, were investigated. ( δ -FeOOH)/MWCNTs nanocomposite was synthesized using a single-step co-precipitation technique. Besides, nano-feroxyhyte and nanocomposite properties were characterized by transmission electron microscopy (TEM),…
Direction-dependent elastic properties and phononic behavior of PMMA/BaTiO 3 nanocomposite thin films
2017
Determination of the anisotropic mechanical properties of nanostructured hybrid films is of great importance to improve fabrication and to enable reliable utility. Here, we employ spontaneous Brillouin light spectroscopy to record the phononic dispersion relation along the two symmetry directions in a supported PMMA (poly(methylmethacrylate))-BaTiO3 hybrid superlattice (SL) with a lattice constant of about 140 nm. Several dispersive elastic modes are resolved for in-plane wave propagation, whereas along the periodicity direction the SL opens a wide propagation stop band for hypersonic phonons and near UV photons both centered at about 280 nm. A thorough theoretical analysis based on the fin…
Electric strength, space charge and surface discharge characterization of nanostructured epoxy-silicate insulating materials
2005
A set of surface discharge ageing procedures, space charge observations and dielectric strength measurements has been implemented on a type of insulating nanofilled epoxy-resin (nanostructured by compatibilised synthetic layered silicates) and on its non-filled base resin. Promising improvements in the electrical behaviour of the nanofilled epoxy, particularly as concerns surface discharge endurance, were detected. Regarding space charge, it was found that its accumulation rate as a function of ageing time is lower for the nanostructured resin. Finally, the nanofilled material evidenced a highly homogeneous behaviour of the dielectric strength data distribution.
Enhanced lithium storage and chemical diffusion in metal-LiF nanocomposites: Experimental and theoretical results
2007
An extra storage of Li has been observed experimentally at low potential in Me/LiF nanocomposites where Me refers to transition metals such as Cu, Co, etc., with a pseudocapacitive behavior characterized by a high rate performance. To understand the mechanistic details of the lithium storage anomaly, we have performed comparative ab initio calculations on the atomic and electronic structure of the nonpolar Cu/ LiF001 and model Li/ LiF001 interfaces. For this aim, we inserted extra Li atoms at several possible sites of the periodic two-dimensional Me/LiF Me= Cu, Li interfaces. The energetically most favorable site for extra Li atom is
Multifunctional superparamagnetic MnO@SiO2 core/shell nanoparticles and their application for optical and magnetic resonance imaging
2012
Highly biocompatible multifunctional nanocomposites consisting of monodisperse manganese oxide nanoparticles with luminescent silica shells were synthesized by a combination of w/o-microemulsion techniques and common sol–gel procedures. The nanoparticles were characterized by TEM analysis, powder XRD, SQUID magnetometry, FT-IR, UV/vis and fluorescence spectroscopy and dynamic light scattering. Due to the presence of hydrophilic poly(ethylene glycol) (PEG) chains on the SiO2 surface, the nanocomposites are highly soluble and stable in various aqueous solutions, including physiological saline, buffer solutions and human blood serum. The average number of surface amino groups available for lig…
Hybrid Nanocomposite Coatings for Application in Construction Materials: Tribological Study
2009
The Nanocomposite group of AIDICO and the Nanomaterials Group of University of Valencia collaborate in the research of new organic-inorganic hybrid materials with application in construction products. Tribological properties and good thermal stability are some of the required specifications for such applications. Some hybrid coatings based on simultaneous formation of epoxy and silica networks are introduced in this work. Elastic modulus and hardness obtained from TDMA analyses and indentation techniques, together with thermal stability by TGA, are the main properties analysed in order to fulfil the requirements for construction coating applications. New routes for obtaining these coatings …
Noble metal nanoparticles in organic matrix
2020
Abstract The purpose of this work is the synthesis and study of the properties of nanocomposite structures created by noble metal (silver) nanoparticles (NP's), an exciting class of materials with unique properties differ from both bulk and atomic behavior, which are self-organize in a thin organic film of copper phthalocyanine (CuPc). The structure and morphology of this material, depending on the amount of deposited silver, was studied in ultrahigh vacuum using transmission electron microscopy (TEM) and photoelectron spectroscopy (PES). Metallic atoms deposited on the surface of an organic substrate diffuse into the substrate, forming NPs with a narrow size distribution, which correlates …
Selective functionalization of halloysite cavity by click reaction: structured filler for enhancing mechanical properties of bionanocomposite films
2014
Selective modification of the inner surface of halloysite nanotubes (HNTs) by the cycloaddition of azides and alkynes (click reaction) was successfully achieved. Fourier transform infrared spectroscopy and thermogravimetry confirmed that the modification involved only the HNT cavity. Morphological investigations evidenced that the functionalized nanotubes formed microfibers and clusters in the micrometer range. By means of the casting method, these nanomaterials were dispersed into biopolymeric matrixes (chitosan and hydroxypropyl cellulose) with the aim of obtaining nanocomposite films with tunable properties from the physicochemical viewpoint. For comparison purposes, we also characterize…
Highly Dispersed Palladium-Polypyrrole Nanocomposites: In-Water Synthesis and Application for Catalytic Arylation of Heteroaromatics by Direct C-H Bo…
2011
Pd@PPy hybrid catalytic materials are synthesized in water via redox polymerization reaction of pyrrole with [Pd(NH 3 ) 4 Cl 2 ]. The nanocomposites formed are composed of highly dispersed palladium particles which are either zerovalent or easily reducible, and are embedded in spherical polypyrrole globules. A unique combination of high palladium dispersion (NP size: 2.4 nm) and elevated palladium content (35 wt%) is obtained. The components of these novel nanocomposites are characterized by means of FTIR, XPS, XRD, SEM, and TEM microscopy techniques. The process of formation in solution is also monitored using UV-visible and DLS techniques. The application of these novel hybrid nanomateria…