Silica From Rice Husk
Mostrando 1-12 de 29 artigos, teses e dissertações.
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1. Biogenic synthesis of silver nanoparticles from thyme extract for functionalization of a bioactive glass produced from rice husk ash
Abstract The rice husk, agro-industrial residue, stands out for having silica, the main oxide former of the bioactive glass. To avoid contamination in this biomaterial, substances with bactericidal properties, like silver can be incorporated. Thus, the objective of this work is the synthesis of silver nanoparticles to functionalize a bioactive glass synthesi
Cerâmica. Publicado em: 2022
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2. Weathering Resistance of Waterborne Polyurethane Coatings Reinforced with Silica from Rice Husk Ash
Abstract: Waterborne polyurethanes (WPUs) are interesting materials for coatings when compared to solvent-based polyurethanes, once that reducing the concentration of volatile organic compounds that are harmful for human health and the environment. However, the WPU has low weathering resistance. In order to improve this behavior among others properties, ino
An. Acad. Bras. Ciênc.. Publicado em: 25/11/2019
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3. Análise da redução da alcalinidade de compósitos cimento-madeira em função da substituição parcial do cimento Portland por pozolanas
RESUMO O objetivo desta pesquisa foi avaliar a redução da alcalinidade de compósitos cimento-madeira, produzido com cimento Portland e partículas residuais de Pinus spp., em função da substituição gradual do cimento Portland pelas pozolanas sílica ativa (SA) metacaulim (MK), cinza volante (CV), escória de alto-forno (EAF), cinza de casca de arroz (
Matéria (Rio J.). Publicado em: 25/11/2019
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4. Synthesis and characterization of asphalt composite precursors using amorphous rice husk silica
Resumo Nesta pesquisa, compósitos asfálticos foram produzidos misturando asfalto com sílica extraída da casca de arroz, com relação asfalto:sílica de 1:0, 1:1,7 e 1:2, e calcinados a 150 ºC. O desenvolvimento das estruturas foi caracterizado por espectroscopia no infravermelho com transformada de Fourier (FTIR), difração de raios X (XRD), microscop
Cerâmica. Publicado em: 06/06/2019
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5. Fracture Properties of Geopolymer Concrete Based on Metakaolin, Fly Ash and Rice Rusk Ash
Geopolymers are exclusively mineral nature and are considered an alternative to materials based on Portland clinker, whose production accounts for about 5% of anthropogenic CO2 emissions in the world. The geopolymer cement concrete (GCC) may be prepared from natural oxide-aluminosilicates such as metakaolin (MK), or synthetic, such as fly ash (FA) together w
Mat. Res.. Publicado em: 17/11/2017
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6. Rice Husk Ash as Raw Material for the Synthesis of Silicon and Potassium Slow-Release Fertilizer
Rice husk ash (RHA) is a waste material produced in large quantities in many regions worldwide, and its disposal can be problematic. This work describes a method for using RHA to synthesize silicon and potassium slow-release fertilizer. The extraction of silica from RHA was accomplished by alkaline leaching with KOH. Different KOH concentrations and reaction
J. Braz. Chem. Soc.. Publicado em: 2017-11
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7. Characterization of Silica Produced from Rice Husk Ash: Comparison of Purification and Processing Methods
As a byproduct of the combustion of rice husk to generate energy, rice husk ash (RHA) is formed by silica and carbon, apart from small amounts of other constituents. Several treatments can be used to increase the purity of the silica obtained, or even produce pure silica. The present study tested the efficiency of different techniques to obtain silica, chara
Mat. Res.. Publicado em: 30/10/2017
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8. Mixing process influence on thermal and rheological properties of NBR/SiO2 from rice husk ash
Abstract Silica was extracted from rice husk ash (RHA) by a sequence of reactions to produce nanosilica. Two laboratory routes, co-coagulation and spray drying, were used to incorporate the nanosilica into the rubber matrix. Samples were characterized regarding filler incorporation efficiency, thermal stability, rheological behavior and morphology. Thermogra
Polímeros. Publicado em: 29/06/2017
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9. Rice husk ash as filler in tread compounds to improve rolling resistance
Abstract In the tire industry carbon black is being replaced by silica as a filler in recent due to the development of “green tires”. Amorphous precipitated silica in combination with a silane coupling agent as a filler in tread compounds can result in fuel savings of 3% to 4% compared to a tire having treads made from compounds with carbon black. This m
Polímeros. Publicado em: 2017-03
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10. Rice Husk Reuse in the Preparation of SnO2/SiO2Nanocomposite
In this study, biogenic SiO2 of high purity and high surface area obtained from rice husk was used for prepare a nanostructured SnO2/SiO2composite. The predominantly amorphous silica was extracted in an acidic route and then the nanocomposite was done via sol-gel route using ethylene glycol and citric acid followed by heat treatment. SiO2 content of the rice
Mat. Res.. Publicado em: 2015-06
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11. Comparison of Kinetic Study of CTMA+ Removal of Molecular Sieve Ti-MCM-41 Synthesized with Natural and Commercial Silica
This work aimed to determine and compare the apparent activation energy, involved in thermal decomposition of CTMA+ from the pores of Ti-MCM-41 synthesized by two different source of silica in order to evaluate their influence in the template removal. The molecular sieves Ti-MCM-41 were synthesized using rice husk ash (RHA), as alternative low cost source of
Mat. Res.. Publicado em: 2015-06
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12. ACIDITY OF MODIFIED MORDENITES SYNTHESIZED FROM RICE HUSK SILICA AND CATALYTIC TRANSFORMATION OF METHYLBUTYNOL
Mordenite (MOR) was synthesized using rice husk silica and modified by base (B), acid (A) or acid-base (AB) and converted to H-form. The modification did not destroy the MOR structure but increased surface area and generated mesopores. Lewis acidity of the parent and modified MOR samples investigated by aluminum NMR and NH3-TPD showed a decrease in the follo
Quím. Nova. Publicado em: 2015-02