Quantum Dots
Mostrando 13-24 de 166 artigos, teses e dissertações.
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13. Synthesis of Hydrotalcite-Supported CdTe Semiconductor Nanocrystals for Electrochemical Detection of Ciprofloxacin
In this work, CdTe quantum dots (QDs) were controllably grown onto the surface of layered double hydroxide (LDH) aiming to develop a sensitive and selective method for the electrochemical detection of ciprofloxacin (CPX). Emission and absorption spectroscopy results as well as high-resolution transmission electron microscopy (HRTEM) images evidenced the form
J. Braz. Chem. Soc.. Publicado em: 23/05/2019
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14. Fluorescent Sensors Based on Cu-Doped Carbon Quantum Dots for the Detection of Rutin
In this paper, Cu-doped carbon quantum dots (Cu-CQDs) were prepared by carrying out thermolysis of Na2[Cu(EDTA)] and hydroxylamine hydrochloride at 300 ºC for 2 h. The as-prepared Cu-CQDs were characterized by UV-Vis, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray diff
J. Braz. Chem. Soc.. Publicado em: 08/04/2019
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15. Functionalization of P3HT with Various Mono- and Multidentate Anchor Groups
Due to its favorable optoelectronic properties and the accessibility via Grignard metathesis (GRIM) polymerization, poly(3-hexylthiophene) (P3HT) is one of the most applied conjugated polymers. The ‘living' nature of GRIM polymerization enables the modification of the polymer and the installation of desired properties. In the present study, two versatile a
J. Braz. Chem. Soc.. Publicado em: 2018-05
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16. PONTOS QUÂNTICOS AMBIENTALMENTE AMIGÁVEIS: DESTAQUE PARA O ÓXIDO DE ZINCO
Semiconductor nanocrystals with sizes in the quantum confinement regime (2-10 nm) present special physical and chemical properties. Additionally, environment-friendly quantum dots (QDs), as zinc oxide and zinc sulfide, offer many practical usages. Herein the ZnO semiconductor nanocrystals properties will be preferentially explored, such as its luminescence,
Quím. Nova. Publicado em: 2017-10
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17. The Role that Electrolytes Play in the Synthesis of Water-Soluble CdTe Quantum Dots Prepared at Ambient Temperature
In this work, we have synthesized CdTe quantum dots (QDs) dispersed in an aqueous medium at ambient temperature, and investigated their optical properties. Synthesis of CdTe QDs in the presence of simple amines removed the need for an additional energy source and inert atmosphere, in a simple and inexpensive experimental setup. The use of ammonia or hydrazin
J. Braz. Chem. Soc.. Publicado em: 2017-07
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18. CÉLULAS SOLARES SENSIBILIZADAS POR PONTOS QUÂNTICOS
Quantum dot solar cells (QDSC) have been subject of extensive research in recent years. QDSC, as a promising alternative to existing solar cells, are among the candidates for next-generation photovoltaic devices that require low cost, high efficiency, so that quantum dots stand out for their unique features and versatile desirable on photovoltaic systems. Th
Quím. Nova. Publicado em: 2017-05
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19. Synthesis, Optical Characterization, and Size Distribution Determination by Curve Resolution Methods of Water-Soluble CdSe Quantum Dots
In this work a colloidal approach to synthesize water-soluble CdSe quantum dots (QDs) bearing a surface ligand, such as thioglycolic acid (TGA), 3-mercaptopropionic acid (MPA), glutathione (GSH), or thioglycerol (TGH) was applied. The synthesized material was characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), UV-visibl
Mat. Res.. Publicado em: 24/10/2016
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20. Nanobiotechnology Solutions against Aedes aegypti
United Nations Children's Fund (UNICEF)/United Nations Development Programme (UNDP)/World Bank/World Health Organization (WHO) implemented the Training in Tropical Diseases (TDR) program with excellent results; however, due to current challenges, this active program requires new and innovative solutions. Nowadays, Aedes aegyptis-borne diseases can be added a
J. Braz. Chem. Soc.. Publicado em: 2016-06
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21. Down- and Up-Conversion Photoluminescence of Carbon-Dots from Brewing Industry Waste: Application in Live Cell-Imaging Experiments
Simple synthetic procedures have been applied to obtain luminescent carbon quantum dots, also referred as C-dots, from an abundant carbon source, that is, from the brewing industry waste. The synthetic procedures have been conducted aiming to investigate the effects of the oxidation stage on the properties of the nanomaterial. C-dots down- and up-conversion
J. Braz. Chem. Soc.. Publicado em: 2015-12
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22. Caracterización óptica de defectos superficialesen puntos cuánticos coloidales de Seleniuro de Cadmio (CdSe)
ABSTRACTIn this work, non-stoichiometric defects and dangling bond defects were optically characterized for CdSe colloidal quantum dots (QDs), which were prepared by the thermal decomposition method. Particularly, the presence of defects linked to a high QD surface to volume ratio was studied. The photoluminescence (PL) spectra of the samples show two bands,
Matéria (Rio J.). Publicado em: 2015-09
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23. Novel and Fast Microwave-Assisted Synthesis of Carbon Quantum Dots from Raw Cashew Gum
Carbon quantum dots (C-dots) with average size of 9 nm were synthesized from an aqueous solution of raw cashew gum (RCG) using a novel and fast microwave-assisted technique which involves two steps. In the first step (partial depolymerization in solution) some monomer units are formed through the autohydrolysis of CG and a small amount of 5-hydroxymethyl fur
J. Braz. Chem. Soc.. Publicado em: 2015-06
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24. EFEITO DA ESTRUTURA MOLECULAR DE LIGANTES DE SUPERFÍCIE EM PONTOS QUÂNTICOS DE CdTe DISPERSOS EM ÁGUA
Water-soluble CdTe quantum dots are synthesized to investigate how short-chain surface ligands bearing -SH, -COOH, and -NH2 groups interact with CdTe during nucleation/growth processes. Their optical properties and colloidal stability after the ligand exchange are also investigated. We then characterize the resulting CdTe by fluorescence, UV–Vis absorption
Quím. Nova. Publicado em: 2015-01