Absorption Spectra
Mostrando 25-36 de 728 artigos, teses e dissertações.
-
25. Effect of compatibiliser on the properties of polypropylene/glass fibre/nanoclay composites
Abstract Glass fibre (GF), nanoclay (NC) and hybrid composites compatibilised with maleic anhydride polypropylene (MAPP) were prepared by extrusion and injection moulding. The fourier transform infra-red spectra revealed the characteristic absorption peaks of MAPP in the compatibilised GF and NC composites. A decrement in the peak intensity of X-ray diffrac
Polímeros. Publicado em: 21/05/2018
-
26. Effect of Different Synthesis Methods on the Textural Properties of Calcium Tungstate (CaWO4) and Its Catalytic Properties in the Toluene Oxidation
Calcium tungstate (CaWO4) crystals were prepared by microwave-assisted hydrothermal (MAH) and polymeric precursor methods (PPM). These crystals were structurally characterized by X-ray diffraction (XRD), N2 adsorption, X-ray absorption near edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS) measurements. The morphology and size of
Mat. Res.. Publicado em: 16/04/2018
-
27. Physiochemical and Optical Properties of GdF3:Pr@LaF3@SiO2 Microspheres
The polyol-based co-precipitation process was employed for synthesis of GdF3:Pr (core) and GdF3:Pr@LaF3 (core-shell) microspheres (MSs). Subsequently, an amorphous silica layer was deposited surrounding the core-shell MSs, which was verified from high-resolution transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX) and FTIR results.
Mat. Res.. Publicado em: 12/04/2018
-
28. Degradation of Poly(Ethylene Oxide) Films Using Crystal Violet
The present study aimed to investigate the degradation of poly(ethylene oxide) (PEO) in the presence of cationic dye crystal violet irradiated under visible light. The preparation of the samples was done in the form of films obtained by casting. Degradation tests were carried out by 120 hours at room temperature. The degradation kinetics of the dye and polym
Mat. Res.. Publicado em: 01/02/2018
-
29. OPTOELECTRONIC PROPERTIES OF TRIPHENYLAMINE BASED DYES FOR SOLAR CELL APPLICATIONS. A DFT STUDY
Abstract: Dye-sensitized solar cells (DSSCs) based on triphenylamine (TPA) as a donor group linked with the acceptor cyanoacrylic acid electron acceptor by 2,2’-bithiophene as π-bridged (D-π-A) has been investigated by Density Functional Theory (DFT) at the B3LYP/6-311G(d,p) level of theory, to establish the conformational orientation of cyanoacrylic aci
Quím. Nova. Publicado em: 2018-02
-
30. TRATAMENTO ELETROQUÍMICO DE EFLUENTE DA PRODUÇÃO DE BIODIESEL USANDO UM ELETRODO DO TIPO ADE: Ti/IrO2-Nb2O5
This work presents the electrochemical treatment of wastewater of biodiesel production, using DSA based on IrO2 and Nb2O5. The anode was prepared by modified Pechini method and characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), in order to evaluate structural and morphological properties and by electrochemical impedance spectros
Quím. Nova. Publicado em: 2018-01
-
31. New Organomineral Complex from Humic Substances Extracted from Poultry Wastes: Synthesis, Characterization and Controlled Release Study
The present study reports the synthesis and characterization of complexes formed among humic (HA) and fulvic acids (FA) derived from poultry wastes and ions Cu2+, Fe2+ and Zn2+. The release of such metals in a buffer solution simulating the soil solution was also evaluated. After complexation, the Fourier transform infrared (FTIR) spectra presented alteratio
J. Braz. Chem. Soc.. Publicado em: 2018-01
-
32. Synthesis and Characterization of Hybrid Ni0.5Zn0.5Fe2O4@SiO2/chitosan
In this work we evaluate the use of silane agent 3-aminopropyltrimethoxysilane and biopolymer chitosan to functionalize ferrites Ni0.5Zn0.5Fe2O4 using the solvent evaporation method aiming at obtaining hybrid material Ni0.5Zn0.5Fe2O4@SiO2/chitosan for use as a biosensor. The nanoparticles before and after the functionalization showed the major phase Ni0.5Zn0
Mat. Res.. Publicado em: 24/08/2017
-
33. ELUCIDATION OF THE ELECTRONIC SPECTRUM CHANGES OF KA-Al3+ COMPLEX BY POTENTIOMETRIC TITRATION, FTIR, 13C RMN AND QUANTUM MECHANICS
Kojic acid (KA) is an organic acid widely used in pharmaceutical industry, mainly as a skin lightening agent. Based on the ability of KA to form complexes with ions, we found the most possible kind of complex formed with cation aluminum. KA-Al3+ complex structures were studied using potentiometric and spectrophotometric (UV) titrations, FTIR and 13C NMR. The
Quím. Nova. Publicado em: 2017-08
-
34. Synthesis, Characterization and Dielectric Properties of New 5-(4-Hydroxyphenyl)- 10,15,20-tri-4-[2-(3-pentadecylphenoxy)ethoxy]phenyl porphyrin and Their Ni, Co and Cu Complexes
New asymmetric cardanol-based porphyrins, free-base and coordinated with Ni, Co and Cu, were synthesized and completely characterized as A3B type. Such porphyrins were obtained aiming improved solubility in polar solvents due insertion of an -OH phenolic group. Their thermal and dielectric properties were also evaluated. Changes in the synthetic route reduce
J. Braz. Chem. Soc.. Publicado em: 2017-06
-
35. Continuous wavelet transform methods for the simultaneous determinations and dissolution profiles of valsartan and hydrochlorothiazide in tablets
ABSTRACT Continuous wavelet transform (CWT) was proposed for the simultaneous determination and dissolution profiles of valsartan (VAL) and hydrochlorothiazide (HCT) in tablets, without the use of a chemical separation procedure. The CWT approach was applied to the original UV spectra and their ratio spectra in the optimal wavelength ranges. After testing se
Braz. J. Pharm. Sci.. Publicado em: 20/04/2017
-
36. Effects of radiant exposure values using second and third generation light curing units on the degree of conversion of a lucirin-based resin composite
Abstract Alternative photoinitiators with different absorption wavelengths have been used in resin composites (RCs), so it is crucial to evaluate the effectiveness of light-curing units (LCUs) on these products. Objective Using Fourier transform infrared analysis (FTIR) in vitro, the effects of varying radiant exposure (RE) values generated by second and t
J. Appl. Oral Sci.. Publicado em: 2017-04