Phase tuning of zirconia nanocrystals by varying the surfactant and alkaline mineralizer

Maheswari, Anurag; Mohan, S.; Kumar, Sachin; Sivakumar, M.

doi:10.1016/j.ceramint.2013.11.109

Cited by 25 publications

(5 citation statements)

References 49 publications

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“…The absorption band at 3400 cm -1 for as-synthesized sample is stronger than that of modified one. Only surface modified nanoparticles exhibited absorption bands in the range of 1000 -1200 cm -1 attributed to silane bonding with Zr which confirms the condensation of trialkoxy group of GPTMS with hydroxyl groups of ZrO 2 [18]. This bonding improves the compatibility of zirconia nanoparticles in dispersion media and prevents their agglomeration.…”

Section: Structural Analysis Of As-synthesized and Surface Modified Zmentioning

confidence: 66%

Corrosion Resistance of 304L SS Spray Coated with Zirconia Nanoparticles

Maheswari

Sivakumar

Indhumathi

et al. 2016

IOP Conf. Ser.: Mater. Sci. Eng.

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Grain boundary character modification employing thermo-mechanical processing in type 304L stainless steel S K Pradhan and S Mandal Abstr act. Influence of substrate temperature on corrosion (in 3.5% NaCl) and wear resistance of nanostructured zirconia thin film coated 304L SS substrates are studied by electrochemical and nano-indentation methods. This analysis shows 304L SS substrate spray coated with nanostructured zirconia at substrate temperature closer to the boiling point of the spray solvent ethanol exhibited good corrosion and wear resistance behaviour. This is because of the compressive stress developed during film fabrication at lower substrate temperature (~50 °C) and hence constrains the indentation plasticity, which leads to higher indentation load than the bare 304L SS. Key words: Zirconia nanoparticles, Spray coating, Corrosion resistance Intr oductionCorrosion is one of the most serious problems faced by industries. Metals normally corrode on exposure to environment and lose its useful properties. Consequently, metal components used in industries have to be repaired or replaced constantly. Though corrosion is inevitable, the rate of corrosion of metals can be reduced by proper choice of material combination [1], using corrosion inhibitors [2] or by surface modification [3] and protective coatings [4]. For instance, stainless steel is widely used for making oil field valves, chemical process equipment, aircraft fittings, fasteners, pump shafts, compressor impeller, nuclear reactor components, gears, paper mill equipment etc., because of its excellent mechanical and corrosion resistance properties. However, in chloride environments at elevated temperatures, austenitic stainless steels are prone to intergranular corrosion due to precipitation of chromium as chromium carbide (Cr 23 C 6 ) at grain boundaries. This process of precipitation requires large amount of chromium and hence the chromium from the adjacent region diffuse resulting in the formation of chromium-depleted zone. This zone is anodic to the unaffected grains and consequently becomes a preferential site for corrosion attack or crack propagation under tensile stress.Presently various coating techniques such as oxidation of an evaporated metal film [5,6], reactive and non-reactive sputtering techniques [7], chemical vapor deposition [8], physical vapour deposition [9] and sol-gel coating [10] are employed to fabricate surface protective coatings for ferrous and non-ferrous alloys. Nevertheless, fabrication of nanocomposite coatings with required proportion of nanostructures like nanoparticles and nanorods of other elements by the above

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Section: Structural Analysis Of As-synthesized and Surface Modified Zmentioning

confidence: 66%

Corrosion Resistance of 304L SS Spray Coated with Zirconia Nanoparticles

Maheswari

Sivakumar

Indhumathi

et al. 2016

IOP Conf. Ser.: Mater. Sci. Eng.

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“…2B 1g ? 3E g ) and the Raman spectrum of cubic zirconia only contains a mode (F 2g ) [30,31]. In the Raman spectrum of the zirconia fibers, six Raman bands at 150, 262, 325, 470, 615 and 640 cm -1 are observed and can be ascribed to tetragonal phase [32][33][34][35].…”

Section: Evolution Of the Precursor Fibersmentioning

confidence: 93%

Rheological behavior, molecular structure of precursor and evolution mechanism: zirconia fibers from polyaceticzirconium precursors

Liu

Wang

et al. 2015

J Sol-Gel Sci Technol

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Polycrystalline zirconia fibers with dense surface and good flexibility were achieved from polyaceticzirconium (abbreviated as PEZ) precursor fibers followed by steam pretreatment and post-calcination. PEZ was synthesized via a one-pot solid-liquid reaction between basic zirconium carbonate and glacial acetic acid in methanol. Rheological behavior of the precursor sol with different concentrations was investigated, the power law model was used to describe the rheological behavior more accurately, and the relationship between the rheology and the spinnability of sol was discussed particularly. For the polymeric structure of PEZ, acetic acid was used as chelating agent and the carboxyl group was acted as a bidentate bridging ligand, which was speculated by FT-IR analysis. The effect of the pretreatment atmosphere on the evolution of the precursor fibers and the microstructure of the final fibers was discussed. The acetate group was removed in the form of molecules, and the final fibers preheated under steam atmosphere had better densification and flexibility than those were not. In addition, crystallization process, phase composition and thermal decomposition were investigated by XRD, Raman spectra and TG/DSC. Graphical Abstract The preheated atmosphere exerts an important influence on the densification and flexibility of zirconia fibers. Under steam atmosphere, acetate group in the precursor fibers is removed in the form of molecules and zirconia fibers sintered at 1050°C for 2 h have a dense surface. However, zirconia fibers not subjected to the steam pretreatment have a large number of voids on the surface due to the decomposition of the organics. Furthermore, the fibers preheated under steam atmosphere have better flexibility than those were not. Therefore, pretreatment under steam atmosphere is essential for the preparation of the dense and flexible fibers.

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“…To address these limitations, several efforts have been made to stabilize the tetragonal phase of ZrO2 and improve its photocatalytic efficiency, including altering the catalyst's physicochemical properties through calcination temperature [12,13]. Previously, we have sythezised Si/ZrO2 catalyst with different calcination temperature which are 350, 550 and 850 °C and tested for photodegradation of 2-chlorophenol (2-CP).…”

Section: Introductionmentioning

confidence: 99%

Understanding the effect of the calcination process on the structure of mesoporous silica zirconia photocatalysts for Bisphenol A degradation

Hassan

Jalil²

2023

Malay. J. Catal.

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The mesoporous silica zirconia (m- SiO2/ZrO2) was successfully synthesized in this study using a microwave method, and the effect of the calcination process was studied. In this study, half of the sample was left untreated (labeled "untreated sample"), while the other half was calcined at 850 °C for 3 hours in an air atmosphere in a muffle furnace to remove the surfactant. X-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet-visible differential reflectance spectroscopy, nitrogen adsorption-desorption spectroscopy, and electron spin resonance spectroscopy were utilized in order to analyze the catalysts that were produced. The findings from the characterization showed that the calcination procedure caused the creation of oxygen vacancies and increased the surface area, both of which affected the photocatalytic activity. The photocatalytic activity of the calcined m-SiO2/ZrO2 (80%) catalyst was superior to that of the untreated m-SiO2/ZrO2 (19%) catalyst. Zirconia's greater surface area and its natural occurrence in the tetragonal phase are both to blame for this phenomenon. In addition, there is the possibility that a greater proportion of oxygen vacancy will result in a smaller band gap and a lower electron-hole recombination rate. After five cycles, the photocatalytic activity exhibited by both catalysts remained unchanged.

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Phase tuning of zirconia nanocrystals by varying the surfactant and alkaline mineralizer

Cited by 25 publications

References 49 publications

Corrosion Resistance of 304L SS Spray Coated with Zirconia Nanoparticles

Corrosion Resistance of 304L SS Spray Coated with Zirconia Nanoparticles

Rheological behavior, molecular structure of precursor and evolution mechanism: zirconia fibers from polyaceticzirconium precursors

Understanding the effect of the calcination process on the structure of mesoporous silica zirconia photocatalysts for Bisphenol A degradation

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