Effect of the Addition of Phosphotungstic Acid on the Thermal Stability of Zirconium Oxide

Hernández-Enríquez, Juan Manuel; García-Alamilla, Ricardo; Sandoval-Robles, G.; Melo-Banda, J.A.; Serrano, Luz Arcelia García

doi:10.15446/dyna.v81n183.32929

Cited by 6 publications

(7 citation statements)

References 20 publications

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“…The phosphotungstic acid grafted ZrO 2 nanoparticles were analyzed with FTIR and the spectra of PWA, ZrO 2 , and PWA/ZrO 2 are shown in the Supporting Information Figure S3; all the relevant peaks are marked in the figure and are denoted appropriately . The PWA/ZrO 2 peaks usually appear in the wave number range of 500 to 1050 cm −1 , but due to its very low concentration (2 and 5%) in the membranes, the peaks are either not apparent or are masked by the high intensity polymer peaks.…”

Section: Resultsmentioning

confidence: 99%

“…With filler nanoparticles, two additional peaks appear at 2 θ values of 27.5 and 32°, and they are attributed to the PWA/ZrO 2 . With PA‐doped sample, the XRD patterns change drastically [Figure (c,d)].…”

Section: Resultsmentioning

confidence: 99%

“…Phosphotungstic acid‐grafted zirconium dioxide (PWA/ZrO 2 ) particles were synthesized following the procedure reported elsewhere . Two grams of ZrO 2 nanoparticles were added to 400 mg of phosphotungstic acid dissolved in 50 mL DI water and the solution was stirred for 24 h on a magnetic stirrer.…”

Section: Methodsmentioning

confidence: 99%

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Dielectric relaxations in phosphoric acid‐doped poly(2,5‐benzimidazole) and its composite membranes

Saleha

Rahul

Nalajala

et al. 2017

J of Applied Polymer Sci

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Poly(2,5‐benzimidazole) (ABPBI)—a promising high‐temperature polymer electrolyte membrane—is characterized over a wide range of temperature (−50 to 220 °C) using broadband dielectric spectroscopy (BDS) to understand the various relaxation processes. The undoped ABPBI membrane shows two major secondary relaxations and a primary α relaxation. The effect of phosphoric acid (PA) and phosphotungstic acid grafted zirconium dioxide (PWA/ZrO2) nanoparticles on the chain relaxation and the proton conductivity is investigated. The phosphoric acid alters the relaxation trends, increases the number of free ions in the polymer matrix, and therefore the conductivity. The shift in the peak frequencies of different chain relaxation processes in the presence of PA and PWA/ZrO2 is attributed to the increase in free volume and the consequent easy motion of the polymer chains. The Fourier transform infra‐red (FTIR) spectroscopy of ABPBI and the acid‐doped composites show all the relevant peaks corresponding to CC, CN stretching, and phosphoric acid/phosphates, confirming the formation of ABPBI and doping with PA. The proton conductivity of the membranes is estimated from electrochemical impedance spectroscopy (EIS). To establish the effect of change in crystallinity on relaxations and proton conductivity, the undoped and PA‐doped membranes are characterized using thermogravimetric analysis and in situ XRD at high temperatures. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44867.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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Dielectric relaxations in phosphoric acid‐doped poly(2,5‐benzimidazole) and its composite membranes

Saleha

Rahul

Nalajala

et al. 2017

J of Applied Polymer Sci

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“…Heteropoly acids contain tungsten, molybdenum or vanadium can be made as treatment solution directly on zirconium, nickel, cerium and titanium alloys [29]. Addition of tungsto-phosphoric acid to zirconia produced strong acidic Lewis sites and is the strongest super acid among all known heteropolyacids [27,28,30].…”

Section: Introductionmentioning

confidence: 99%

Effect of phosphotungstic acid on surface properties and bond strength of resin cement to zirconia

Metwaly

Al-Zordk

El-Dafrawy

et al. 2022

Preprint

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Background The purpose of this in vitro study was to evaluate the effect of phosphotungstic acid pre-treatment on the surface properties of zirconium oxide ceramics and the microtensile bond strength (µTBS) between zirconium oxide ceramics and resin cement. Methods A total of 26 sintered zirconia blocks were randomly divided according to surface pre-treatment into four groups; group C (n = 6): no treatment (control), group S (n = 6): air-borne particle abrasion followed by Silano Pen treatment, group P1 (n = 7): Phosphotungstic acid 1gm/ 50 mL, and group P2 (n = 7): Phosphotungstic acid 2gm/50 mL. From each group, one zirconia block was examined using X-Ray Diffraction and scanning electron microscope. Also, one zirconia block from groups P1 and P2 was examined using Fourier-transform infrared spectroscopy. A total of 20 zirconia blocks were bonded to corresponding pre-constructed composite blocks using adhesive resin cement. Each zirconia-composite assembly was sectioned to obtain microbars of 1 mm2. A 20 microbars from each group were selected and aged (3500 thermocycles between 5°C and 55°C), then the µTBS test was performed using a universal testing machine (0.5 mm/min). The µTBS results was analyzed using one-way ANOVA test. Results Group P2 recorded the highest µTBS (23.824 ± 5.9 MPa) between all studied groups, while Group C recorded the lowest µTBS (12.19 ± 4.67 MPa). One-way ANOVA revealed a significant difference (P < 0.05) between all groups. The mode of failure was predominantly adhesive in Groups C, P1, and S, while group P2 showed cohesive and adhesive failures. Conclusions The phosphotungstic acid (2gm/50 mL) improved the bond strength of zirconia ceramics without phase transformation and composition changes.

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“…30 The addition of tungsto-phosphoric acid to zirconia created strong acidic Lewis sites and is the strongest super acid among all known heteropolyacids. 29,31,32 Micro-tensile tests have a superior featured strength than macro-tensile tests and this advantage makes micro-tensile test more popular and most used. 28,[33][34][35] The aim of this study was to assess the impact of acid pre-treatments (piranha solution, hot acid solution, and heteropolyacid solution) on the microtensile bond strength of monolithic zirconia restorations.…”

Section: Introductionmentioning

confidence: 99%

Influence of chemical etching on bond strength of translucent zirconia to resin cement

Al-Zordk

Dawood

2021

Egyptian Dental Journal

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Purpose: To assess the effect of chemical pre-treatments (piranha, hot acid, and heteropolyacid) on the bond strength (μTBS) to zirconia. Materials and Methods:A total of 8 sintered zirconia blocks were randomly assigned into 4 groups; Group I: Air abrasion, Group II: Air abrasion and etching using piranha solution (3H 2 SO 4 : 1H 2 O 2 ), Group III: Air abrasion and etching using hot acid solution (1HNO 3 : 1HF), and Group IV: Air abrasion and etching using heteropolyacid solution (2gm/50 mL). Zirconia blocks were bonded to their corresponding pre-constructed composite blocks using adhesive resin cement. For each group, each assembly was sectioned to obtain 20 microbars. All microbars were thermocyled (10,000), then the μTBS test was done with the aid of a Universal Testing machine. To determine the mode of failure, each specimen was examined under stereomicroscope (x40). One-way ANOVA and Post Hoc Tukey tests were used. Results:The piranha pre-treatment displayed the lowest bond strength (16.82 ±5.97 MPa), while heteropolyacid pre-treatment had higher bond strength (26.22 ±4.05 MPa). One-way ANOVA test indicated statistical significant difference between the studied groups (P<.001). No significant difference was observed between control and piranha groups, also between hot acid and heteropolyacid groups. However, there were statistical significant differences between the control and heteropolyacid groups, and between piranha and heteropolyacid groups.Conclusions: According to the current findings; The novel surface pre-treatment with heteropolyacid (2gm/50 mL) performed well to improve bonding to air-abraded zirconia-based ceramics. The hot acids etching pre-treatment enhanced the bonding to zirconia.

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Effect of the Addition of Phosphotungstic Acid on the Thermal Stability of Zirconium Oxide

Cited by 6 publications

References 20 publications

Dielectric relaxations in phosphoric acid‐doped poly(2,5‐benzimidazole) and its composite membranes

Dielectric relaxations in phosphoric acid‐doped poly(2,5‐benzimidazole) and its composite membranes

Effect of phosphotungstic acid on surface properties and bond strength of resin cement to zirconia

Influence of chemical etching on bond strength of translucent zirconia to resin cement

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