Modified Silica
Mostrando 1-12 de 150 artigos, teses e dissertações.
-
1. Bioactive SiO2-K2O-CaO-P2O5 glass-ceramic scaffold prepared using polyurethane foam template
Abstract A glass-ceramic in the SiO2-K2O-CaO-P2O5 quaternary system was prepared by substituting the Na2O component with K2O to avoid Na2Ca2Si3O9 formation upon thermal treatment since this phase decreases apatite formation kinetics on glass material. To form the glass-ceramic, a modified sol-gel method involving solution precipitation, followed by reagents
Cerâmica. Publicado em: 2023
-
2. Evaluation of the use of silica-alumina refractory waste as a supplementary cementitious material
Abstract The use of supplementary cementitious materials (SMCs) is one of the three essential factors for the sustainability of the cement industry. To reduce CO2 emissions, several studies have introduced new methods for the utilization of industrial wastes such as the addition into cementitious materials. The objectives of this study were to chemically and
Cerâmica. Publicado em: 2021-06
-
3. A Green Procedure Using Disposable Pipette Extraction to Determine Polycyclic Aromatic Sulfur Heterocycles in Water Samples and Solid Petrochemical Residues
A simple and efficient method using reduced amounts of solvents for the determination of polycyclic aromatic sulfur heterocycles (PASHs) in aqueous matrices from a lagoon and leachate solid waste from a petrochemical industry is proposed. The target analytes were previously concentrated using the disposable pipette extraction (DPX) technique applying gas chr
J. Braz. Chem. Soc.. Publicado em: 2021-02
-
4. Synthesis and Characterization of Hybrid Polymer Based on Functionalized Silica as Efficient Adsorbent for Heavy Metal Ions from Aqueous Solution
An organic-inorganic hybrid material based on a silica matrix and functionalized with imidazole group was successfully synthesized by the sol-gel process. The characterization techniques enabled the confirmation of the proposed structure as well as the effectiveness of the imidazole ring functionality in the structure of the material. It is insoluble in wate
J. Braz. Chem. Soc.. Publicado em: 2020-10
-
5. Sobre reformas y políticas sanitarias en la España de los últimos años del franquismo y la transición democrática
An organic-inorganic hybrid material based on a silica matrix and functionalized with imidazole group was successfully synthesized by the sol-gel process. The characterization techniques enabled the confirmation of the proposed structure as well as the effectiveness of the imidazole ring functionality in the structure of the material. It is insoluble in wate
Hist. cienc. saude-Manguinhos. Publicado em: 2020-10
-
6. Effect of nano-silica on Portland cement matrix
Resumo O uso de nanopartículas é uma tendência recente que pode assumir um papel importante para melhorar o desempenho mecânico do cimento Portland. O objetivo deste estudo é avaliar o efeito da nanossílica na matriz de cimento Portland. A distribuição do tamanho das partículas da matriz de cimento Portland foi modificada pela incorporação de 11,
Rev. IBRACON Estrut. Mater.. Publicado em: 13/12/2019
-
7. Performance eletrocatalítica frente a nitrito de um filme híbrido de fosfomolibdato e sílica organomodificada
RESUMO Materiais híbridos orgânico-inorgânicos nanoestruturados são produzidos com a finalidade de desenvolver e/ou aprimorar uma propriedade de interesse. Uma forma de obtenção de materiais híbridos é através da imobilização de um componente inorgânico em uma rede de sílica organicamente modificada (ormosil). Neste trabalho, um polioxometalato
Matéria (Rio J.). Publicado em: 25/11/2019
-
8. Silica/Titania Graphite Composite Modified with Chitosan and Tyrosinase Employed as a Sensitive Biosensor for Phenolic Compounds
A mesoporous, high surface area and conductive silica/titania graphite composite modified with chitosan and functionalized with tyrosinase was prepared. The composite was obtained by the sol-gel method and the surface of the resultant material was modified with chitosan solutions containing 5, 10 and 15% by mass. The textural characterization showed that eve
J. Braz. Chem. Soc.. Publicado em: 24/10/2019
-
9. Surface Silanization of Graphene Oxide Under Mild Reaction Conditions
The functionalization of graphene oxide with organosilanes is an important strategy to yield graphene-silica composites as well as to create nanomaterials for use as reinforcement in polymer nanocomposites and corrosion-inhibiting coatings for metals, among other uses. However, depending on the reaction conditions used, the organosilanes tend to self-condens
J. Braz. Chem. Soc.. Publicado em: 24/10/2019
-
10. Synthesis of Hybrid Monolithic Columns Using a Click Chemistry Reaction for Application in Capillary Liquid Chromatography
Hybrid monolithic columns present characteristics of both silica and organic monoliths, such as good mechanical properties, wide pH tolerance, high permeability and stability and little swelling or shrinkage. A common way to prepare this type of material is by using alkoxysilanes and organic monomers via the sol-gel process and click chemistry reactions. In
J. Braz. Chem. Soc.. Publicado em: 24/10/2019
-
11. Synthesis of Highly Ordered Mesoporous MCM-41: Selective External Functionalization by Time Control
Sol-gel synthesis is commonly used to modify the surface of mesoporous silica nanoparticles (MSN) with organic groups through the co-condensation method. The template removal, and the site-controlled addition of organic groups and their partial occlusion inside the framework walls are still a challenge in the one-pot synthesis. Here, we optimize the synthesi
J. Braz. Chem. Soc.. Publicado em: 12/08/2019
-
12. Avaliação da atividade antimicrobiana e adsortividade de nanopartículas de sílica dopadas com CuO
RESUMO Nanomateriais exibem propriedades que se aplicam nas mais variadas áreas, entre estas, na área da saúde e agrícola, nas quais as pesquisas vêm aumentando progressivamente. Neste trabalho sintetizamos nanopartículas de sílica não porosas dopadas com óxido de cobre (CuO) usando método de Stöber com pequenas modificações. Em adição, a ativ
Matéria (Rio J.). Publicado em: 20/05/2019