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1.
Materials (Basel) ; 15(8)2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35454596

RESUMO

The open-layered structure of Vanadium pentoxide (V2O5) has triggered significant interest in exploring its energy-related application as lithium (Li) intercalation cathode material. Various methods are extensively studied to improve the Li diffusion using thin films or nanoarchitecture. In this work, high-quality two-dimensional (2D) inverse opal α-V2O5 films were synthesized via a modified 'dynamic hard template' infiltration strategy using sacrificial polystyrene spheres (PS, a diameter of 530 nm) photonic crystal as a template. The new material exhibited an excellent porous array with featured structural colors in a large area. The electrochromic behavior was explored by combining bandgap and electrochemical characterization. On the one hand, the intercalation/deintercalation of Li+ played an important role in the bandgap (Eg), and thereafter on the visible range transmittance through changing the film's stoichiometry and the valence of vanadium ions. On the other hand, the asymmetry of the lattice due to the disordered distribution of Li+ within the V2O5 interlayer and/or the formation of an irreversible phase explained the change in transmittance with voltage.

2.
RSC Adv ; 11(14): 8065-8072, 2021 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-35423313

RESUMO

Pure anatase two dimensional (2D) TiO2 inverse opal (IO) films, consisting of a highly ordered hexagonal-patterned structure, are synthesized from various sized polystyrene spheres (PS) as colloidal template simply coupled with TiOSO4 aqueous solution as TiO2 precursor using a "dynamic-hard-template infiltration" strategy. Herein, the TiOSO4 solution is directly infiltrated into the interstices of the 2D self-assembled PS opal template at an air/water interface resulting in a TiOSO4/PS opal composite film floating on the surface of water which was further deposited onto ITO or silicon substrates. Calcination of the obtained opal composite films at temperatures ranging from 300 to 550 °C resulted in 2D TiO2 IO films with various pore sizes having an inverse moth's eye structure. Based on EDS measurements, sulfur ions S6+ were detected in the IO films calcined up to 550 °C. In order to eliminate these S6+ ions and obtain pure anatase 2D TiO2 IO, aqueous immersion was performed after calcination without disturbance of the IO ordered structure. Surface morphology, crystal phase and optical transmittance of the TiO2 IO films, were concurrently investigated by SEM, Raman and UV-vis-NIR. Owing to their precisely adjustable structure, the obtained TiO2 2D IO films exhibited structural colors varying from pale purple, to blue, to polychrome as the array period increases. The films obtained on ITO substrates were successfully used as active electrodes in the fabrication of electrochromic (EC) devices.

3.
Mater Sci Eng C Mater Biol Appl ; 110: 110674, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32204103

RESUMO

Composite materials aimed at bone tissue engineering need to have suitable bioactivity in order to promote cell proliferation and adhesion. In this article, we study the potential of boronic acids to improve the bioactivity of chitosan-based composite materials. Samples were prepared using boronic acid functionalised chitosan and Bioglass 45S5. These composite materials, prepared by freeze-drying, exhibit 3D interconnected porosity. The materials were fully characterized using scanning electron microscopy (SEM), FT-IR and x-ray diffraction. Their bioactivity was assessed by immersion in simulated body fluid and cell cytotoxicity assays. Composite materials containing boronic acid show no toxicity for Mouse Sertoli (TM4), Human embryonic kidney 293 (Hek293) and Human bone marrow/stroma (HS-5) cells, as opposed to composites containing non-functionalised chitosan.


Assuntos
Ácidos Borônicos/farmacologia , Cerâmica/farmacologia , Quitosana/farmacologia , Engenharia Tecidual/métodos , Ácidos Borônicos/síntese química , Ácidos Borônicos/química , Morte Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Cerâmica/síntese química , Cerâmica/química , Quitosana/síntese química , Quitosana/química , Humanos , Espectroscopia de Infravermelho com Transformada de Fourier , Alicerces Teciduais/química , Difração de Raios X
4.
Chem Commun (Camb) ; 52(5): 892-5, 2016 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-26576930

RESUMO

A hierarchically porous anatase TiO2 coated-WO3 2D inverse opal (IO) bilayer film was fabricated on ITO glass using a layer by layer route with a hierarchically porous TiO2 top layer and an ordered super-macroporous WO3 2D IO bottom layer. This novel TiO2 coated-WO3 2D IO bilayer film was evaluated for photochromic applications.

5.
Mar Drugs ; 13(6): 3849-76, 2015 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-26096274

RESUMO

Northern shrimp (Pandalus borealis) oil, which is rich in omega-3 fatty acids, was recovered from the cooking water of shrimp processing facilities. The oil contains significant amounts of omega-3 fatty acids in triglyceride form, along with substantial long-chain monounsaturated fatty acids (MUFAs). It also features natural isomeric forms of astaxanthin, a nutritional carotenoid, which gives the oil a brilliant red color. As part of our efforts in developing value added products from waste streams of the seafood processing industry, we present in this paper a comprehensive characterization of the triacylglycerols (TAGs) and astaxanthin esters that predominate in the shrimp oil by using HPLC-HRMS and MS/MS, as well as 13C-NMR. This approach, in combination with FAME analysis, offers direct characterization of fatty acid molecules in their intact forms, including the distribution of regioisomers in TAGs. The information is important for the standardization and quality control, as well as for differentiation of composition features of shrimp oil, which could be sold as an ingredient in health supplements and functional foods.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Óleos/análise , Pandalidae/química , Espectrometria de Massas em Tandem/métodos , Animais , Ácidos Graxos Ômega-3/análise , Ácidos Graxos Ômega-3/isolamento & purificação , Espectroscopia de Ressonância Magnética/métodos , Óleos/química , Óleos/isolamento & purificação , Triglicerídeos/análise , Triglicerídeos/química , Triglicerídeos/isolamento & purificação , Xantofilas/análise , Xantofilas/química , Xantofilas/isolamento & purificação
6.
Chem Commun (Camb) ; 50(17): 2184-6, 2014 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-24429973

RESUMO

A 'dynamic hard-template' infiltration strategy for crack-free large-area synthesis of 2D WO3 inverse opal (IO) films on ITO substrates using a wide range of sizes of sacrificial PS spheres is reported. Thus prepared WO3 IO films were successfully used as an active electrode in the fabrication of an electrochromic device.

7.
J Hazard Mater ; 183(1-3): 554-64, 2010 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-20691534

RESUMO

Porous silica materials S8, S12, S16, and SBA with controllable pore structures and morphology were synthesized by varying the type or alkyl chain length of the surfactant. Diverse amino-functionalized organic-inorganic hybrid porous materials were then prepared by post-grafting. Depending on the relation between the pore diameter of the porous silica materials and the size and content of the moiety to be grafted, the functionalized materials exhibited varying degrees of decline of structure properties, i.e. regular arrangement of pores, specific surface area, pore size, and pore volume. The hybrid silica materials have been employed as heavy metal ions adsorbents from simulated drinking water at room temperature. The results indicated that the diverse pore structures and different amino group densities influence the heavy metal ions adsorption of functionalized silicas significantly. The best adsorbent was found to be monoamino-functionalized silica S16-1N, which could effectively remove heavy metal Cd(II), Pb(II), Fe(III), as well as Mn(II). The good performance can be attributed to the accessibility of effective amino groups in the pores, as well as the suitable pore structure with high specific surface area of 728 m(2)/g and total pore volume of 0.34 cm(3)/g.


Assuntos
Metais Pesados/isolamento & purificação , Dióxido de Silício/síntese química , Poluentes Químicos da Água/isolamento & purificação , Abastecimento de Água/análise , Porosidade , Dióxido de Silício/química
8.
Nanoscale Res Lett ; 4(11): 1335-42, 2009 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-20628456

RESUMO

Tungsten trioxide (WO(3)) nanostructures were synthesized by hydrothermal method using sodium tungstate (Na(2)WO(4).2H(2)O) alone as starting material, and sodium tungstate in presence of ferrous ammonium sulfate [(NH(4))(2)Fe(SO(4))(2).6H(2)O] or cobalt chloride (CoCl(2).6H(2)O) as structure-directing agents. Orthorhombic WO(3) having a rectangular slab-like morphology was obtained when Na(2)WO(4).2H(2)O was used alone. When ferrous ammonium sulfate and cobalt chloride were added to sodium tungstate, hexagonal WO(3) nanowire clusters and hexagonal WO(3) nanorods were obtained, respectively. The crystal structure and orientation of the synthesized products were studied by X-ray diffraction (XRD), micro-Raman spectroscopy, and high-resolution transmission electron microscopy (HRTEM), and their chemical composition was analyzed by X-ray photoelectron spectroscopy (XPS). The optical properties of the synthesized products were verified by UV-Vis and photoluminescence studies. A photodegradation study on Procion Red MX 5B was also carried out, showing that the hexagonal WO(3) nanowire clusters had the highest photodegradation efficiency.

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