Quantum Dots Nanocrystals
Mostrando 1-12 de 20 artigos, teses e dissertações.
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1. Improving Photoluminescence Quantum Yield of CdTe Quantum Dots Using a Binary Solvent (Water + Glycerin) in the One-Pot Approach Synthesis
The present work describes the comparison of the optical and structural properties between CdTe quantum dots (QD) synthesized in water and in the binary solvent (water + glycerin) via one-pot approach synthesis. The optical properties of the nanocrystals obtained with different synthesis parameters were characterized by UV-visible and photoluminescence spect
J. Braz. Chem. Soc.. Publicado em: 2021-04
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2. NANOCRISTAIS DE PEROVSKITAS COLOIDAIS: HISTÓRICO, PROPRIEDADES E APLICAÇÕES
Recently, a new class of materials, the Perovskite Nanocrystals, also known as perovskite quantum dots (PQDs) has emerged. Perovskite nanocrystals are promising in optoelectronics due to their quantum confinement properties, narrow photoluminescence bands with short decay times, optically tunable bandgaps, easy surface passivation and high photoluminescent q
Quím. Nova. Publicado em: 2020-09
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3. (Bio)conjugation Strategies Applied to Fluorescent Semiconductor Quantum Dots
Quantum dots (QDs) are semiconductor nanocrystals, which present unique photophysical properties, enabling their application as new fluorescent platforms for biomedical sciences. Colloidal QDs are end-capped with organic or inorganic compounds, not only to prevent their agglomeration but also to provide reaction sites for the attachment of targeting (bio)mol
J. Braz. Chem. Soc.. Publicado em: 24/10/2019
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4. 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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5. 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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6. 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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7. NANOCOMPÓSITOS BASEADOS EM QUANTUM DOTS DE CdS E CdS:Cu SUPORTADOS EM MERCAPTOPROPILSÍLICA:síntese, caracterização e aplicação em fotocatálise. / NANOCOMPOSITES BASED ON CdS AND CdS:Cu QUANTUM DOTS SUPPORTED ON MERCAPTOPROPYL-SILICA: synthesis, characterization and application in photocatalysis.
Textile dyes and other commercial dyestuffs have become a focus of environmental remediation efforts in the last few years. Considerable attention has been expended recently on the photocatalytic oxidative degradation of colored contaminants in waste water over semiconductor surfaces. In this work, we evaluated the photocatalytic activities of nanocomposites
Publicado em: 2011
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8. SÍNTESE, CARACTERIZAÇÃO E APLICAÇÃO EM FOTOCATÁLISE DE NANOCRISTAIS SEMICONDUTORES DE SULFETO DE CÁDMIO SUPORTADOS EM ARGILA TIOLADA. / SYNTHESIS, CHARACTERIZATION AND APPLICATION IN PHOTOCATALYS OF SEMICONDUCTOR CADMIUM SULFIDE NANOCRYSTALS SUPPORTED ONTO THIOLATED CLAY.
O desafio da nanotecnologia, ciência que estuda os fenômenos e manipulação de materiais em escala nanométrica (1-100 nm), é o controle de composição, forma e tamanho de nanomateriais, parâmetros que influenciam as propriedades físicas, químicas, óticas e eletrônicas. Dentro desse contexto, os quantum dots (QDs) são nanopartículas semicondutora
Publicado em: 2011
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9. O estado da arte da síntese de semicondutores nanocristalinos coloidais
Colloidal semiconductor nanocrystals, also known as quantum dots, have attracted great attention since they have interesting size-dependent properties due to the quantum confinement effect. These nanoparticles are highly luminescent and have potential applications in different technological areas, including biological labeling, light-emitting diodes and phot
Química Nova. Publicado em: 2010
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10. Sistemas de análises químicas em fluxo explorando mecanismos de re-alimentação, calibração multivariada e outras abordagens para melhoria em desempenho / Flow systems exploiting feed-back mechanisms, multivariate calibration and other strategies for improving the analytical performance
Studies focusing on performance of intelligent analytical flow systems, association with multivariate calibration or use of nanocrystals as sensitizers were carried out. Moreover, improvements related to modifications in flow pattern were evaluated with emphasis to in-line dialysis. To this end, a strategy for implementing simultaneous determinations of iron
Publicado em: 2010
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11. Sínteses, caracterizações e estudo de pontos quânticos de calcogenetos de cádmio
CdS, CdSe, CdSxSe1-x and Cd1-xMnxS quantum dots were successfully grown in the glass matrix SNAB [40SiO2.30Na2CO3.1Al2O3.29B2O3 (mol%)] synthesized by the Fusion Method, when subjected to certain thermal treatment. The glass transition temperature (Tg) of the glass matrix SNAB was found by Differential Scanning Calorimetry (DSC) in order to set the temperatu
Publicado em: 2009
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12. Síntese e estudo das propriedades ópticas e magnéticas de pontos quânticos de Pb1-xMnxS crescidos em matrizes vítreas
In this Thesis PbS and Pb1-xMnxS quantum dots (nanocrystals), hosted in glass matrix, were synthesized and characterized. Optical absorption (OA), Electron Paramagnetic Resonance (EPR) and Magnetization curves (SQUID) were used to characterize the as-prepared nanocrystals. Within the range of 0.41 eV (gap of bulk PbS) to 3.5 eV (gap of bulk MnS) the OA bands
Publicado em: 2008