Isabel Izquierdo‐Barba, Edésia Martins Barros de Sousa, A. Doadrio, Antonio Luis Doadrio, Joaquín Pérez‐Pariente, Africa Martínez, Florence Babonneau, Maria Vallet‐Regí,
Tópico(s): Metal-Organic Frameworks: Synthesis and Applications
2009 - Springer Science+Business Media | Journal of Sol-Gel Science and Technology
Produção Nacional
Revisado por pares
Andreza de Sousa Andrada, Daniel Andrada Maria, Ricardo Geraldo de Sousa, Edésia Martins Barros de Sousa,
Tópico(s): Aerogels and thermal insulation
2009 - Springer Science+Business Media | Journal of Materials Science
Produção Nacional
Revisado por pares
Patrícia A. Robles-Dutenhefner, Kelly A. da Silva Rocha, Edésia Martins Barros de Sousa, Elena V. Gusevskaya,
Cobalt-containing MCM-41 was used as a heterogeneous catalyst for the liquid-phase aerobic oxidation of isolongifolene, one of the most available sesquiterpenes. The material was prepared by direct incorporation of cobalt into the framework through the hydrothermal method, and was characterized by ICP-AES, N2 adsorption–desorption, TEM, XRD, SAXS, XPS, and H2-TPR techniques. Characterizations suggest that cobalt introduced into MCM-41 exists mainly in a single-site Co2+ state, whereas the amounts ...
Tópico(s): Catalytic Processes in Materials Science
2009 - Elsevier BV | Journal of Catalysis
Karynne Cristina de Souza, Nelcy Della Santina Mohallem, Edésia Martins Barros de Sousa,
Tópico(s): Iron oxide chemistry and applications
2009 - Springer Science+Business Media | Journal of Sol-Gel Science and Technology
Produção Nacional
Revisado por pares
Luciana Spíndola Sales, Patrícia A. Robles-Dutenhefner, Diego Luiz Nunes, Nelcy Della Santina Mohallem, Elena V. Gusevskaya, Edésia Martins Barros de Sousa,
Silica embedded with transition metals exhibits adequate properties for applications in catalysis, sensors and optics. Cobalt–silica (Co–SiO2) nanocomposites were prepared by the sol–gel method and thermally treated at 700, 900, 1100 and 1250 °C. Characterization of the samples was performed by XRD and BET nitrogen adsorption. The performance of the nanocomposites was investigated by catalysis reactions of oxidation. These catalysts were found to be recyclable showing a catalytic activity even after ...
Tópico(s): Nanomaterials for catalytic reactions
2003 - Elsevier BV | Materials Characterization
Produção Nacional
Revisado por pares
Karynne Cristina de Souza, Germán Salazar-Álvarez, José D. Ardisson, W. A. A. Macedo, Edésia Martins Barros de Sousa,
Magnetite nanoparticles coated by mesoporous silica were synthesized by an alternative chemical route using a neutral surfactant and without the application of any functionalization method. The magnetite (Fe3O4) nanoparticles were prepared by precipitation from aqueous media, and then coated with mesoporous silica by using nonionic block copolymer surfactants as the structure-directing agents. The mesoporous SiO2-coated Fe3O4 samples were characterized by x-ray diffraction, Fourier-transform infrared ...
Tópico(s): Catalytic Processes in Materials Science
2008 - IOP Publishing | Nanotechnology
Produção Nacional
Revisado por pares
Karynne Cristina de Souza, José D. Ardisson, Edésia Martins Barros de Sousa,
Tópico(s): Nanomaterials for catalytic reactions
2008 - Springer Science+Business Media | Journal of Materials Science Materials in Medicine
Produção Nacional
Revisado por pares
Andreza de Sousa Andrada, Karynne Cristina de Souza, S.C. Reis, Ricardo Geraldo de Sousa, Dario Windmöller, J.C. Machado, Edésia Martins Barros de Sousa,
Ordered mesoporous materials such as SBA-15 possess a network of channels and pores with a well-defined size in the nanoscale range (2–50 nm). This particular pore architecture makes them suitable candidates for a variety of applications. Different techniques have been used to measure pore diameters. PALS (positron annihilation lifetime spectroscopy) nanoprobe has been used to investigate free volume in several materials, including mesoporous silica. PALS can be used to find out if the micropore and ...
Tópico(s): Copper Interconnects and Reliability
2008 - Elsevier BV | Journal of Non-Crystalline Solids
Produção Nacional
Revisado por pares
Tatiana Santos de Araujo, S.O. Souza, Edésia Martins Barros de Sousa,
Biocompatible phosphate materials are used in different applications like bone and dental implants, drug delivery systems and others, but could also be applied in inorganic sunscreens. Using sunscreens is extremely necessary, because long time exposure to sun can cause skin cancer. In this work chemical precipitation method has been used to produce hydroxyapatite. Cr3+, Zn2+ and Fe3+ doped samples were characterized using powder X-Ray Diffraction (XRD) and Optical Absorption techniques. X-ray diffraction ...
Tópico(s): Pigment Synthesis and Properties
2010 - IOP Publishing | Journal of Physics Conference Series
Produção Nacional
Revisado por pares
Tatiana Santos de Araujo, S.O. Souza, Walter Miyakawa, Edésia Martins Barros de Sousa,
The crescent number of skin cancer worldwide gives impulse to the development of sunscreen that can both prevent skin cancer and also permit gradual tanning. In this work, the synthesis of hydroxyapatite and tricalcium phosphate nanocrystalline powders was investigated in order to obtain materials with optical properties and appropriate size for sunscreen. Pure, Zn2+-doped and Mn2+-doped hydroxyapatite (HAP) and tricalcium phosphate (β-TCP) were produced by the wet precipitation process using diammonium ...
Tópico(s): Skin Protection and Aging
2010 - Elsevier BV | Materials Chemistry and Physics
Produção Nacional
Revisado por pares
Andreza de Sousa Andrada, Karynne Cristina de Souza, Edésia Martins Barros de Sousa,
Synthetic hydroxyapatite is widely used in medicine and dentistry due its notable biocompatibility and bioactivity properties. The hydroxyapatite incorporation into silica has demonstrated excellent bioactivity or biodegradability, according to the content of calcium ions. Procedures to obtain ordered mesoporous silicates rely on the micelle-forming properties of a surfactant, whose chemical composition, size and concentration control the structural dimensions of the final material. This paper reports ...
Tópico(s): Nanoparticle-Based Drug Delivery
2007 - Elsevier BV | Acta Biomaterialia
Produção Nacional
Revisado por pares
Daniel Crístian Ferreira Soares, Tiago Hilário Ferreira, Carolina A. Ferreira, Valbert Nascimento Cardoso, Edésia Martins Barros de Sousa,
In the present study, boron nitride nanotubes (BNNTs) were synthesized from an innovative process and functionalized with a glycol chitosan polymer in CDTN (Centro de Desenvolvimento da Tecnologia Nuclear) laboratories. As a means of studying their in vivo biodistribution behavior, these nanotubes were radiolabeled with (99m)Tc and injected in mice. Their size, distribution, and homogeneity were determined by photon correlation spectroscopy (PCS), while their zeta potential was determined by laser Doppler ...
Tópico(s): Boron Compounds in Chemistry
2011 - Elsevier BV | International Journal of Pharmaceutics
Produção Nacional
Revisado por pares
Luciana Maria de Hollanda, G Cury, Rafaella FC Pereira, Gracielle A Ferreira, Andreza de Sousa Andrada, Edesia MB Sousa, Marcelo Lancellotti,
Abstract Background This study aimed the use of mesoporous silica under the naturally transformable Neisseria meningitidis , an important pathogen implicated in the genetic horizontal transfer of DNA causing a escape of the principal vaccination measures worldwide by the capsular switching process. This study verified the effects of mesoporous silica under N. meningitidis transformation specifically under the capsular replacement. Methods we used three different mesoporous silica particles to verify ...
Tópico(s): Parasitic Infections and Diagnostics
2011 - BioMed Central | Journal of Nanobiotechnology
Produção Nacional
Revisado por pares
Andreza de Sousa Andrada, Edésia Martins Barros de Sousa,
The characteristics of mesoporous silica prepared at different temperatures and the behavior of this system relating to the microencapsulation of a model drug were investigated. The preparation of mesoporous materials was initiated with the dissolution of a surfactant in distilled water and strong acid medium. After this, tetraethyl orthosilicate was added under agitation. The mixture was heated for 24 h at the synthesis temperature (60 °C, 80 °C, 100 °C and 130 °C) under static conditions. The surfactant ...
Tópico(s): Zeolite Catalysis and Synthesis
2006 - Elsevier BV | Journal of Non-Crystalline Solids
Produção Nacional
Revisado por pares
L.B. Fagundes, Taiane Sousa, Andreza de Sousa Andrada, V.V. Silva, Edésia Martins Barros de Sousa,
The development of mesoporous materials offers new possibilities for incorporating biological agents into silica structures and controlling the release kinetics from the matrix due to its well-arranged pore architecture. Indeed, the introduction of appropriate organic compounds into these ceramics has presented excellent results regarding drug release control. In this paper, two types of materials were used to evaluate drug delivery: SBA-15 and a hybrid SBA-15-collagen. The samples were charged ...
Tópico(s): Silicone and Siloxane Chemistry
2006 - Elsevier BV | Journal of Non-Crystalline Solids
Produção Nacional
Revisado por pares
Kelly A. da Silva Rocha, Patrícia A. Robles-Dutenhefner, Edésia Martins Barros de Sousa, Elena F. Kozhevnikova, Ivan V. Kozhevnikov, Elena V. Gusevskaya,
Pd–H3PW12O40/SiO2 catalyzes the one-pot transformation of (+)-citronellal to menthol via acid-catalyzed cyclization followed by Pd-catalyzed hydrogenation, with 92% yield of menthol at 100% citronellal conversion and 85% stereoselectivity for the desired (−)-menthol.
Tópico(s): Catalysis for Biomass Conversion
2006 - Elsevier BV | Applied Catalysis A General
Produção Nacional
Revisado por pares
Gracielle Ferreira Andrade, Daniel Crístian Ferreira Soares, Raquel Gouvêa dos Santos, Edésia Martins Barros de Sousa,
In the present work, mesoporous silica SBA-16 nanoparticles with an innovative cubic mesoporous matrix, practically unexplored in terms of functionalization and in vitro studies, has been synthesized and functionalized using two different silanizing agents: 3-amino-propyl-triethoxysilane (APTES) and n-propyltriethoxysilane (PTES). The pure and functionalized silica nanoparticles were physicochemically and morphologically characterized, the results of which presented adequate characteristics for in ...
Tópico(s): Bone Tissue Engineering Materials
2012 - Elsevier BV | Microporous and Mesoporous Materials
Produção Nacional
Revisado por pares
E.A. Périgo, S. C. Silva, Edésia Martins Barros de Sousa, Anderson Santos De Freitas, Renato Cohen, L.C.C.M. Nagamine, Hidetoshi Takiishi, Fernando José Gomes Landgraf,
Nanoparticles were prepared from a NdFeB-based alloy using the hydrogen decrepitation process together with high-energy ball milling and tested as heating agent for magnetic hyperthermia. In the milling time range evaluated (up to 10 h), the magnetic moment per mass at H = 1.59 MA m−1 is superior than 70 A m2 kg−1; however, the intrinsic coercivity might be inferior than 20 kA m−1. The material presents both ferromagnetic and superparamagnetic particles constituted by a mixture of phases due to the ...
Tópico(s): Advanced MRI Techniques and Applications
2012 - IOP Publishing | Nanotechnology
Produção Nacional
Revisado por pares
Gracielle Ferreira Andrade, Daniel Crístian Ferreira Soares, Ramon K.S. Almeida, Edésia Martins Barros de Sousa,
A mesoporous material sphere based on silica, SBA‐16, was chemically modified with alkoxysilane using two different solvents: methanol and toluene. The influence of the chemical modification of the matrix on the release rate of a model drug was also studied. The structural characteristics of the materials were evaluated by small‐angle X‐ray diffraction, N 2 adsorption, and transmission electron microscopy. The functionalization of the matrix was evaluated using thermal analysis, FTIR spectroscopy, ...
Tópico(s): Covalent Organic Framework Applications
2012 - Hindawi Publishing Corporation | Journal of Nanomaterials
Produção Nacional
Revisado por pares
Patrícia A. Robles-Dutenhefner, Marcelo Gomes Speziali, Edésia Martins Barros de Sousa, Eduardo N. dos Santos, Elena V. Gusevskaya,
Sol–gel palladium silica composites are active catalysts for the selective hydrogenation of myrcene. The temperature of the thermal treatment of the catalyst is essential for its selectivity. Catalysts treated at 1100 °C give monohydrogenated products with excellent combined selectivity of 90–95% at almost complete conversion of the substrate. The obtained products arise from the σ-alkyl and/or η3-allyl intermediates formed by the interaction of the palladium catalyst with both terminal CC bonds ...
Tópico(s): Mesoporous Materials and Catalysis
2005 - Elsevier BV | Applied Catalysis A General
A. Doadrio, Edésia Martins Barros de Sousa, Isabel Izquierdo‐Barba, A. Doadrio, Joaquín Pérez‐Pariente, Maria Vallet‐Regí,
Mesoporous silica SBA-15 was prepared to evaluate its effectiveness as a matrix for the controlled delivery of macrolide-type antibiotics. Two types of material were used to evaluate the delivery: calcined samples and samples functionalized with octyltrimethoxysilane and octadecyltrimethoxysilane. The samples were charged with the macrolide antibiotic erythromycin and the release assays were carried out in vitro. It has been observed that the release rate decreases as the population of hydrophobic – ...
Tópico(s): Chemical Synthesis and Characterization
2005 - Royal Society of Chemistry | Journal of Materials Chemistry
A. Doadrio, Edésia Martins Barros de Sousa, A. Doadrio, Joaquín Pérez‐Pariente, Isabel Izquierdo‐Barba, Maria Vallet‐Regí,
Mesoporous silica SBA-15 was prepared to evaluate its application as gentamicin drug delivery system. Two procedures were used to evaluate the delivery: calcined powder and disk conformed. The samples were charged with gentamicin sulphate and the experiments were carried out in vitro. No significant difference between powder and disk was observed in the tests. The release profiles exhibited a pronounced initial burst release effect of 60%, followed by a very slow release pattern. A new HPLC method ...
Tópico(s): Analytical Chemistry and Chromatography
2004 - Elsevier BV | Journal of Controlled Release
Produção Nacional
Revisado por pares
Patrícia A. Robles-Dutenhefner, Márcio José da Silva, Luciana Spíndola Sales, Edésia Martins Barros de Sousa, Elena V. Gusevskaya,
Tópico(s): Oxidative Organic Chemistry Reactions
2004 - Elsevier BV | Journal of Molecular Catalysis A Chemical
Produção Nacional
Revisado por pares
Kelly A. da Silva Rocha, Patrícia A. Robles-Dutenhefner, Edésia Martins Barros de Sousa, Elena F. Kozhevnikova, Ivan V. Kozhevnikov, Elena V. Gusevskaya,
Silica-supported heteropoly acid H3PW12O40 (PW) is a very efficient and environmentally benign solid acid catalyst for the liquid-phase cyclization of (+)-citronellal (1). The reaction has been performed in cyclohexane solutions at 15–40 °C yielding (−)−isopulegol (2) and (+)-neo-isopulegol (3) as main products in almost 100% total selectivity at 95–100% conversion, with an 80% selectivity to more valuable product 2. No PW leaching is observed during the reaction, and the catalysts can be recovered and reused several ...
Tópico(s): Oxidative Organic Chemistry Reactions
2004 - Elsevier BV | Catalysis Communications
Produção Nacional
Revisado por pares
Alysson A.C. Magalhães, Diego Luiz Nunes, Patrícia A. Robles-Dutenhefner, Edésia Martins Barros de Sousa,
The sol–gel process is an efficient method to produce porous solids for catalyst reactions. Titania, in the form of anatase, is a photo-catalyst and the scientific and technological interest in its use in the field of wastewater treatment has grown. In this work, porous TiO2 was prepared by the sol–gel method using solutions of tetraisopropylorthotitanate containing polyethylene glycol (PEG) with different molecular weights. Gel samples were dried at 100 °C and then thermally treated at 520 °C for ...
Tópico(s): Catalytic Processes in Materials Science
2004 - Elsevier BV | Journal of Non-Crystalline Solids
Produção Nacional
Revisado por pares
Edésia Martins Barros de Sousa, A.O. Porto, P. J. Schilling, Maria do Carmo Martins Alves, Nelcy Della Santina Mohallem,
Porous silica gels have been prepared by the sol–gel method using tetraethoxysilane (TEOS), ethanol and water with two dopants, CuCl and CuSO4, with different copper contents (1 and 5 mol%). The samples were prepared as monolithic shapes, dried at 110°C for 24 h and heat treated at 500, 900 and 1100°C. Their structural evolution was studied by gas absorption, X-ray diffraction and X-ray absorption spectroscopy. All samples showed a stable structure of pores up to 900°C and a strong densification process ...
Tópico(s): ZnO doping and properties
2000 - Elsevier BV | Journal of Physics and Chemistry of Solids
Produção Nacional
Revisado por pares
Tiago Hilário Ferreira, Luciana Maria de Hollanda, Marcelo Lancellotti, Edésia Martins Barros de Sousa,
Nanostructured materials have been widely studied concerning their potential biomedical applications, primarily to selectively carry specific drugs or molecules within a tissue or organ. In this context, boron nitride nanotubes (BNNTs) have generated considerable interest in the scientific community because of their unique properties, presenting good chemical inertness and high thermal stability. Among the many applications proposed for BNNTs in the biomedical field in recent years, the most important ...
Tópico(s): Graphene research and applications
2014 - Wiley | Journal of Biomedical Materials Research Part A
Produção Nacional
Karynne Cristina de Souza, Gracielle Ferreira Andrade, Ingrid Vasconcelos, Iara Maíra de Oliveira Viana, Christian Fernandes, Edésia Martins Barros de Sousa,
In the present work, magnetic nanoparticles embedded into mesoporous silica were prepared in two steps: first, magnetite was synthesized by oxidation–precipitation method, and next, the magnetic nanoparticles were coated with mesoporous silica by using nonionic block copolymer surfactants as structure-directing agents. The mesoporous SiO2-coated Fe3O4 samples were functionalized using octadecyltrimethoxysilane as silanizing agent. The pure and functionalized silica nanoparticles were physicochemically ...
Tópico(s): Analytical chemistry methods development
2014 - Elsevier BV | Materials Science and Engineering C
Produção Nacional
Revisado por pares
Raquel C. S. Azevedo, Ricardo Geraldo de Sousa, W. A. A. Macedo, Edésia Martins Barros de Sousa,
Tópico(s): Nanopore and Nanochannel Transport Studies
2014 - Springer Science+Business Media | Journal of Sol-Gel Science and Technology
Produção Nacional
Revisado por pares
Gracielle Ferreira Andrade, Viviane Silva Gomide, Armando Silva‐Cunha, Alfredo Goes, Edésia Martins Barros de Sousa,
Tópico(s): Chemical Synthesis and Characterization
2014 - Springer Science+Business Media | Journal of Materials Science Materials in Medicine