Nanomaterials
Mostrando 1-12 de 122 artigos, teses e dissertações.
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1. Efficient Encapsulation and Controlled Release of N,N-Diethyl-3-methylbenzamide (DEET) from Oil-in-Water Emulsions Stabilized by Cationic Nanocellulose and Silica Nanoparticles
Oil-in-water emulsions containing N,N-diethyl-3-methylbenzamide (DEET) were developed aiming to extend the sustained release of the active compound, by using two oppositely charged nanomaterials, namely silica nanoparticles (SiNP) and cationic cellulose nanofibrils (CCNF), as stabilizers, and a mixture of food-grade nonionic surfactants to avoid precipitatio
Journal of the Brazilian Chemical Society. Publicado em: 2023
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2. Iron Cobaltite (FeCo2O4) Nanocatalysts for Water-Oxidation: Effects of Annealing Temperature on Catalytic Properties
The development of efficient, stable, and non-precious metal water oxidation catalysts (WOCs) is a matter of importance for sustainable energy research. In this work, iron cobaltite (FeCo2O4) nanoparticles were prepared by the coprecipitation method, and we present the effect of heat treatment (250, 350, 450, 650 and 900 °C) on the catalytic properties. Cat
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. Atomic Absorption Spectrometry as an Alternative to Determine the Presence of Gold Nanoparticles on or in Silica Matrix
Two different gold-silica-based nanomaterials were prepared: (i) silica-supported gold nanoparticles (AuNP/SiO2); and (ii) gold-silica core-shell nanoparticles (AuNP@SiO2). Three strategies for sample treatment (S), consisting in acid treatments, were employed: (S1) HNO3; (S2) HNO3 + HCl; and (S3) HF + HNO3 + HCl, applying microwave oven digestion for S2 and
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. GRAPHEN-PHENYL-NH2 AS NANOCARRIER: A DENSITY FUNCTIONAL THEORY STUDY
Recently, graphene and modified graphene as one of the most suitable and the most important carbon nanomaterials have been introduced for drug delivery. In this paper, we have studied the binding characteristics of the EDC-NHS cross-linking process of graphene-phenyl-NH2 and 5-aminolevulinic acid (ALA) drug in both gas and solvent phases by density functiona
Química Nova. Publicado em: 2022
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5. Desenvolvimento de software e interface para o controle por retroalimentação atrasada em sistemas eletroquímicos
In this paper, we show the development of a LabVIEW algorithm able to apply the delayed feedback control on oscillatory electrochemical reactions. The coupling of the control and the experiments was carried out by a real-time apparatus, measuring the faradaic current and, in sequence, applying a calculated circuit voltage as an analog output. The setup was u
Quím. Nova. Publicado em: 2021-06
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6. Nanofibras eletrofiadas e suas aplicações: avanços na última década
In recent years there has been an increasing interest in the development of nanomaterials with improved properties compared to their counterparts at the micro- and macroscopic scale. In this context, nanofibers obtained by electrospinning technique are highly attractive due to the unique combination of high surface area/volume ratio, porosity, flexibility, m
Quím. Nova. Publicado em: 2021-06
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7. IMIDAZOL E CATÁLISE: UM PAR PERFEITO
The imidazole (IMZ) ring presents several chemical properties that turns it into a versatile acid-basic/nucleophilic catalyst. The discovery of the biological properties of histidine (amino acid with IMZ ring) instigates the study of this class of compounds. It is found in nature in several enzymes such as chymotrypsin and RNAses due to these properties. Thi
Quím. Nova. Publicado em: 2021-03
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8. NANOMATERIAIS PLASMÔNICOS: PARTE II. QUÍMICA DE COORDENAÇÃO DE SUPERFÍCIE E SUA APLICAÇÃO EM SENSORES E CATALISADORES
In this second part we will discuss how surface chemistry properties of plasmonic nanomaterials can be tailored by applying coordination chemistry, supramolecular and materials chemistry approaches, in which nanoparticles with well-controlled features conjugated with properly chosen molecules are the basis of functional organized structures that can be appli
Quím. Nova. Publicado em: 2020-12
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9. NANOMATERIAIS PLASMÔNICOS: PARTE I. FUNDAMENTOS DA ESPECTROSCOPIA DE NANOPARTÍCULAS E SUA RELAÇÃO COM O EFEITO SERS
We perform an analysis of plasmonic nanomaterials in a two part review, the first of which constitutes the present work. Here, attention is given to the fundamentals of metal nanoparticle optical properties. It is discussed the principles regarding the excitation of localized surface plasmon modes in nanostructures of different sizes, shapes and surrounding
Quím. Nova. Publicado em: 2020-12
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10. Gold Nanoparticle/Tetrapyridylporphyrin Hybrid Material: Spectroscopic and Electrocatalytic Properties and Sensor Application
An electrocatalytic active hybrid material prepared by successive stepwise coordinative deposition of 20 nm diameter gold nanoparticles (AuNP) with 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine (TPyP) on fluorine-doped tin oxide (FTO) substrates previously modified with 3-mercaptopropylsilane is described. Their interaction and assembly were studied by UV-Vis
J. Braz. Chem. Soc.. Publicado em: 2020-11
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11. Ações contra a Covid-19 na População com Síndrome de Down
An electrocatalytic active hybrid material prepared by successive stepwise coordinative deposition of 20 nm diameter gold nanoparticles (AuNP) with 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine (TPyP) on fluorine-doped tin oxide (FTO) substrates previously modified with 3-mercaptopropylsilane is described. Their interaction and assembly were studied by UV-Vis
Arq. Bras. Cardiol.. Publicado em: 2020-11
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12. SÍNTESE E CARACTERIZAÇÃO DE PONTOS QUÂNTICOS AMBIENTALMENTE AMIGÁVEIS, UM MEIO SIMPLES DE EXEMPLIFICAR E EXPLORAR ASPECTOS DA NANOCIÊNCIA E NANOTECNOLOGIA EM CURSOS DE GRADUAÇÃO
Nanotechnologies and nanomaterials are very current and interesting topics and can be used as interdisciplinary tools in education. They can be used to work in a practical and interesting way with lots of subjects. In chemistry teaching it can be particularly important to consolidate the nanomaterials, nanotechnology and characterization teaching. Among the
Quím. Nova. Publicado em: 2020-06