Effect of sol-gel processing parameters on structure of zirconia

Silva, D. G. da; Vasconcelos, Wander L.

doi:10.1590/0366-6913201965s12606

Cited by 13 publications

(10 citation statements)

References 34 publications

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“…Zirconia and titania are other popular materials for ceramic membranes. In sol-gel method, zirconium alkoxides are often used as precursors to prepare zirconia sols [109,110]. However, some zirconium alkoxides such as zirconium propoxide is water-reactive, which could produce agglomerates rather than stable nanoparticles.…”

Section: Reverse Osmosis and Nanofiltration Membranesmentioning

confidence: 99%

A Review on Reverse Osmosis and Nanofiltration Membranes for Water Purification

et al. 2019

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Sustainable and affordable supply of clean, safe, and adequate water is one of the most challenging issues facing the world. Membrane separation technology is one of the most cost-effective and widely applied technologies for water purification. Polymeric membranes such as cellulose-based (CA) membranes and thin-film composite (TFC) membranes have dominated the industry since 1980. Although further development of polymeric membranes for better performance is laborious, the research findings and sustained progress in inorganic membrane development have grown fast and solve some remaining problems. In addition to conventional ceramic metal oxide membranes, membranes prepared by graphene oxide (GO), carbon nanotubes (CNTs), and mixed matrix materials (MMMs) have attracted enormous attention due to their desirable properties such as tunable pore structure, excellent chemical, mechanical, and thermal tolerance, good salt rejection and/or high water permeability. This review provides insight into synthesis approaches and structural properties of recent reverse osmosis (RO) and nanofiltration (NF) membranes which are used to retain dissolved species such as heavy metals, electrolytes, and inorganic salts in various aqueous solutions. A specific focus has been placed on introducing and comparing water purification performance of different classes of polymeric and ceramic membranes in related water treatment industries. Furthermore, the development challenges and research opportunities of organic and inorganic membranes are discussed and the further perspectives are analyzed.

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Section: Reverse Osmosis and Nanofiltration Membranesmentioning

confidence: 99%

A Review on Reverse Osmosis and Nanofiltration Membranes for Water Purification

et al. 2019

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“…Table 2 presents comparison of ZrO 2 performance with other reported ZrO 2 membranes. Silva and Vasconcelos [27] developed zirconia using sol-gel technique, while studying the influence of molar ratios of water on zirconia structure. According to [27], higher molar ratio of water favored the increase of pore diameter and surface area.…”

Section: Gas Separation Performance Of Zirconia Membranementioning

confidence: 99%

“…Silva and Vasconcelos [27] developed zirconia using hydrolysis and condensation process. They studied the effects of molar ratios of concentrations of H 2 O on zirconia structure.…”

Section: Introductionmentioning

confidence: 99%

Nano-Porous Zirconia Membranes for Separation of Hydrogen from Carbon Dioxide

Shah¹,

Mirza²,

Butt³

et al. 2021

Pol. J. Environ. Stud.

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A defect free nano-porous zirconia membrane was fabricated using sol-gel method for the separation of H 2 gas from a mixture of H 2 and CO 2 . Agglomeration of sol was controlled by releasing hydrolyzing water slowly by the reaction of solvent such as alcohol and acetic acid unlike conventional technique. FE-SEM image of ten times coated membrane showed a uniform zirconia layer of 885 nm thickness, coated on α-Al 2 O 3 support. The membrane had pore size of 6 nm. Membrane was fired at 400, 450, and 500ºC to remove organic content, to estimate the final calcination temperature. XRD study confirmed that the zirconia was transformed into tetragonal phase. The crystallite size (D) was 5.0, 10.13, and 16.28 nm for dried and calcined zirconia powder respectively, at 25, 400 and 500ºC. Scherrer's equation was used to estimate crystallite size. TGA showed that there was no significant loss of mass above 600ºC. Gas permeance of the supported ZrO 2 layers was studied by the development of laboratory scale gas permeation setup. The permeance for H 2 and CO 2 as single component at 300ºC, respectively, was 15.21 × 10 −6 and 2.0 × 10 −6 mol/(m 2 sPa). Permeance of membrane in 75:25 H 2 :CO 2 binary feed mixture was 9.96×10 −6 and 1.21×10 −6 mol/(m 2 sPa), respectively, at 300 °C. The selectivity of hydrogen over CO 2 in ZrO 2 membrane for 75:25 H 2 /CO 2 binary feed mixture was 8.23. These results demonstrated that the membranes offer high potential for purification of hydrogen and carbon dioxide in a mixture at an elevated temperature.

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“…No entanto cabe ressaltar a questão do custo de obtenção de substâncias fontes do elemento praseodímio e outros terras-raras que é relativamente alta [26], além disso a cor amarela obtida pelo zircão ((Zn, Pr)SiO₄) pelo método cerâmico tradicional é de obtenção demorada e para usos que necessitam de material fino (menor que 1 µm) a remoagem ocasiona perda da intensidade do tom amarelo [12,32]. Além disso, uma sucinta revisão sobre alguns dos principais métodos de síntese, sumarizado na Tabela III, permite relembrar alguns detalhes de cada método com exemplos de vantagens e algumas desvantagens no sentido de propriedades, mas também levando em conta aspectos ambientais que mereceriam um olhar caso as rotas que ainda não são amplamente utilizadas em escala industrial venham a ser no futuro [8,19,20,21,33,56,57].…”

Section: Pbunclassified

“…O método sol-gel tem sido referido como alternativa ambientalmente amigável quando os reagentes utilizados favorecem a geração de subprodutos de reação com baixo caráter poluidor, como o álcool etílico, embora os alcóxidos precursores e outros reagentes possam ter um custo elevado. As temperaturas de calcinação são geralmente mais baixas [57,58].…”

Section: Método Pechiniunclassified