An efficient, template-free solution-chemical route to nanostructured ZnO sponges is presented: A mixture of Zn(NO)·6HO, Zn(OAc)·2HO, and triethanolamine in methanol was evaporated to a highly viscous liquid and rapidly heated to >200 °C for 1-3 min to achieve highly porous, nanocrystalline sponges of ZnO. The viscous precursor concentrate obtained on evaporation in air was characterized by TG, DSC, and IR spectroscopy, and the product ZnO sponges by XRD, SEM, TEM, and IR spectroscopy. The fast reaction forming ZnO started at 140 °C and finished within a few seconds.
View Article and Find Full Text PDFThe influence of ZnO nanoparticles on the thermal degradation behavior of poly(methyl methacrylate) (PMMA) was tested using thermoanalytical techniques. The studied materials were investigated using TG, DTA, EGA, XRD, SEM and TEM. The ZnO nanoparticles were synthesized via precipitation by adding LiOH into Zn2+ water/ethylene glycol solutions.
View Article and Find Full Text PDFMater Sci Eng C Mater Biol Appl
February 2016
ZnO nanoparticles are utilized in an ever growing number of products and can, therefore, be readily encountered in our everyday life. Human beings' outermost tissues consist of different epithelia and are, therefore, the most exposed to materials from the environment. In this paper, Caco-2 and Calu-3 cell lines were used, having been previously broadly applied for in vitro modelling of intestinal and respiratory epithelia, respectively.
View Article and Find Full Text PDFThe synthesis of highly antimicrobial nanocrystalline zinc oxide and its covalent modifications are presented. In order to achieve further improvement of antimicrobial activity, the surface of ZnO was effectively modified with selected silanes comprising amino- and ionic liquid-functionalities. We demonstrate for the first time ionic liquid surface immobilization on ZnO and the application of this hybrid material for antimicrobial purposes.
View Article and Find Full Text PDFWe investigated the efficiency of poly(methyl methacrylate)-b-poly(methacrylic acid) (PMMA-b-PMAA) diblock copolymers as reactive polymeric surfactants for the functionalization of ZnO nanoparticles (NPs) of diameters ranging from 20 to 80 nm. PMMA-b-PMAA with molar masses in the range of 20.000 and 30.
View Article and Find Full Text PDFZnO nanoparticles were prepared in a typical single-step experimental procedure, in different water-to-ethylene glycol volume ratios at a moderate temperature. Morphological studies performed by SEM and TEM have revealed two different types of nanosized particles: hexagonal facetted nanoparticles and spherical ones. The obtained ZnO nanoparticles were further coated with the coupling reagent tetraethyl orthosilicate (TEOS), in situ and ex situ.
View Article and Find Full Text PDFA rapid, microwave-assisted hydrothermal method has been developed to access ultrafine ZnO hexagonal microrods of about 3-4 μm in length and 200-300 nm in width by using a 1:5 zinc nitrate/urea precursor system. The size and morphology of these ZnO materials can be influenced by subtle changes in precursor concentration, solvent system, and reaction temperature. Optimized conditions involve the use of a 1:3 water/ethylene glycol solvent system and 10 min microwave heating at 150 °C in a dedicated single-mode microwave reactor with internal temperature control.
View Article and Find Full Text PDFThe title compound has been synthesized under solvothermal conditions by reacting vanadium(V) oxytriisopropoxide with terephthalic acid in N,N-dimethylformamide. A combination of synchrotron powder diffraction, infrared spectroscopy, scanning and transmission electron microscopy, and thermal and chemical analysis elucidated the chemical, structural and microstructural features of a new 2D layered inorganic-organic framework. Due to the low-crystallinity of the final material, its crystal structure has been solved from synchrotron X-ray powder diffraction data using a direct space global optimization technique and subsequent constraint Rietveld refinement.
View Article and Find Full Text PDFJ Colloid Interface Sci
August 2011
We present a simple, low-temperature synthesis of pure ZnO nanoparticles and polymer-ZnO hybrid materials formed by the NaOH-mediated conversion of poly(zinc dimethacrylate) in 1-butanol. The polymer poly(zinc dimethacrylate) was used as a precursor to prepare neat ZnO particles. It has a double role in the ZnO formation process, acting as a template and simultaneously controlling the crystal growth.
View Article and Find Full Text PDFLayered ZnO microspheric particles were prepared by the thermal decomposition of layered hydrozincite (LZnHC), which was synthesized from zinc nitrate and urea in a water/PEG400 mixture. The influence of the starting reagents, their concentrations, and the amount of PEG in the water/PEG400 mixture on the particle growth was observed. The chemical aspect of the particle growth was proposed in the frame of the partial charge model (PCM), and the formation of [Zn(OH)(2)(OH(2))(4)](0) and [Zn(OH)(HCO(3))(OH(2))(3)](0) was predicted for the solid phase.
View Article and Find Full Text PDFZnO nanoparticles of different sizes, from 20 to 200 nm in length, and morphologies, nanorods and coral-like structures, were synthesized via a simple one-pot synthesis by refluxing an oversaturated solution of zinc acetylacetonate hydrate in 1-butanol and isobutanol. On the basis of (1)H and (13)C NMR experiments, the reactions in both alcohols were found to proceed via the alcoholytic C-C cleavage of the acetylacetonate ligand, followed by the hydrolytic formation of the reactive Zn-OH intermediate from the water molecules present in the precursor hydrate species and/or those released during the condensation cycle. The zinc acetylacetonate conversion into ZnO in isobutanol is significantly slower than in the case when 1-butanol was used as both the medium and the reagent.
View Article and Find Full Text PDFJ Nanosci Nanotechnol
July 2008
Cu nanoparticles were prepared in di(ethylene glycol) by a reduction reaction of Cu (II) acetate precursor to metallic Cu. The size and morphology of the synthesized particles were studied in dependence of the concentration of the starting compound and the temperature conditions of reaction were varied to determine the correlation with the size and morphology of the synthesized particles. The morphology and size of the resulting copper (I) oxide as an intermediate product and metallic Cu particles as a final product are strongly dependent on the concentration of the starting compound, thus indicating differences in the mechanism of the reduction reaction and, consequently, the mechanism of particle formation.
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