Improving the mechanical stability of proton conducting SPEEK membranes by in situ precipitation of zirconium phosphate phenylphosphonates

RSC Advances ◽  
2016 ◽  
Vol 6 (43) ◽  
pp. 36606-36614 ◽  
Author(s):  
Monica Pica ◽  
Roberto D'Amato ◽  
Anna Donnadio ◽  
Donatella Capitani ◽  
Elisabetta Troni ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Proton Conductivity ◽  
Zirconium Phosphate ◽  
Mechanical Stability ◽  
Proton Conducting ◽  
The Stability

Zirconium phosphate phenylphosphonate nanoparticles improve mechanical properties and the stability of the proton conductivity of composite SPEEK membranes.

An analysis of the transport properties and mechanical stability of rapidly solidified Al-Sb alloy

2015 ◽  
Vol 10 (2) ◽  
pp. 2663-2681
Author(s):  
Rizk El- Sayed ◽  
Mustafa Kamal ◽  
Abu-Bakr El-Bediwi ◽  
Qutaiba Rasheed Solaiman
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Melt Spinning ◽  
Elastic Moduli ◽  
Mechanical Stability ◽  
Microstructural Analysis ◽  
Alloy System ◽  
Antimony Content ◽  
The Stability ◽  
Rapidly Solidified

The structure of a series of AlSb alloys prepared by melt spinning have been studied in the as melt–spun ribbons  as a function of antimony content .The stability  of these structures has  been  related to that of the transport and mechanical properties of the alloy ribbons. Microstructural analysis was performed and it was found that only Al and AlSb phases formed for different composition.  The electrical, thermal and the stability of the mechanical properties are related indirectly through the influence of the antimony content. The results are interpreted in terms of the phase change occurring to alloy system. Electrical resistivity, thermal conductivity, elastic moduli and the values of microhardness are found to be more sensitive than the internal friction to the phase changes. 

scholarly journals Longitudinal Tension and Mechanical Stability of a Pressurized Straw Tube

Instruments ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 27
Author(s):  
Levan Glonti ◽  
Temur Enik ◽  
Vladimir Kekelidze ◽  
Alexander Kolesnikov ◽  
Dmitry Madigozhin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Charged Particle ◽  
Measurement Technique ◽  
Mechanical Stability ◽  
Stability Conditions ◽  
Particle Detectors ◽  
Straw Tube ◽  
Special Measurement ◽  
The Stability ◽  
Tube Study

For the development of charged particle detectors based on straw tubes operating in vacuum, a special measurement technique is required for the evaluation of their mechanical properties. A summary of the known equations that govern straw behavior under internal pressure is provided, and a new experimental method of a strained pressurized straw tube study is presented in this paper. The Poisson’s ratio of the straw wall, which defines the stability conditions of a built-in tube, was measured for the NA62 spectrometer straw, and its minimum pre-tension was estimated.

scholarly journals New crosslinkers for electrospun chitosan fibre mats. I. Chemical analysis

2012 ◽  
Vol 9 (75) ◽  
pp. 2551-2562 ◽  
Author(s):  
Marjorie S. Austero ◽  
Amalie E. Donius ◽  
Ulrike G. K. Wegst ◽  
Caroline L. Schauer
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Mechanical Stability ◽  
Dissolution Tests ◽  
Natural Polysaccharide ◽  
Biomedical Field ◽  
The Stability ◽  
Scanning Electron

Chitosan (CS), the deacetylated form of chitin, the second most abundant, natural polysaccharide, is attractive for applications in the biomedical field because of its biocompatibility and resorption rates, which are higher than chitin. Crosslinking improves chemical and mechanical stability of CS. Here, we report the successful utilization of a new set of crosslinkers for electrospun CS. Genipin, hexamethylene-1,6-diaminocarboxysulphonate (HDACS) and epichlorohydrin (ECH) have not been previously explored for crosslinking of electrospun CS. In this first part of a two-part publication, we report the morphology, determined by field emission scanning electron microscopy (FESEM), and chemical interactions, determined by Fourier transform infrared microscopy, respectively. FESEM revealed that CS could successfully be electrospun from trifluoroacetic acid with genipin, HDACS and ECH added to the solution. Diameters were 267 ± 199 nm, 644 ± 359 nm and 896 ± 435 nm for CS–genipin, CS–HDACS and CS–ECH, respectively. Short- (15 min) and long-term (72 h) dissolution tests (T 600 ) were performed in acidic, neutral and basic pHs (3, 7 and 12). Post-spinning activation by heat and base to enhance crosslinking of CS–HDACS and CS–ECH decreased the fibre diameters and improved the stability. In the second part of this publication, we report the mechanical properties of the fibres.

scholarly journals Effect of Metallic Inclusions on the Compressive Strength of Cement-Based Materials

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Tomáš Ficker
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Mechanical Stability ◽  
Transition Zones ◽  
Metallic Inclusions ◽  
Cement Based Materials ◽  
Concrete Materials ◽  
Materials Used ◽  
The Stability ◽  
Critical Limits

In the concrete foundations, materials come into contact with bedrocks. The surfaces of bedrocks are often covered by sharp protrusions called asperities. Although geotechnical engineers have developed a reliable theory for assessing the mechanical stability of rocky terrains, the stability of transition zones between concrete and sharp asperities remains unsolved. Due to the large pressures that exist in these transition zones, the invasive influence of sharp asperities on the integrity of the concrete raises a question about possible changes of the mechanical properties of concrete materials used in foundations. These circumstances have inspired experiments in which metallic needles of various lengths have been embedded into cement-based materials to assess the influence of the needles on the compressive strength. This influence has been quantified, and the critical limits identifying the changes of material integrity have been determined. It has been conjectured that sharp rock asperities or needle-like rods of steel reinforcement in concrete may cause similar changes of material integrity as the metallic needles used in the experiments performed.

Preparation, Proton Conductivity and Mechanical Properties of Nafion 117-Zirconium Phosphate Sulphophenylphosphonate Composite Membranes

Fuel Cells ◽  
2009 ◽  
Vol 9 (4) ◽  
pp. 381-386 ◽  
Author(s):  
M. Casciola ◽  
D. Capitani ◽  
A. Donnadio ◽  
V. Frittella ◽  
M. Pica ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Proton Conductivity ◽  
Zirconium Phosphate ◽  
Composite Membranes

scholarly journals The Effect of Sulfated Zirconia and Zirconium Phosphate Nanocomposite Membranes on Fuel-Cell Efficiency

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 263
Author(s):  
Rudzani Sigwadi ◽  
Touhami Mokrani ◽  
Phumlani Msomi ◽  
Fulufhelo Nemavhola
Keyword(s):  
Fuel Cell ◽  
Proton Conductivity ◽  
Water Uptake ◽  
Zirconium Phosphate ◽  
Zro2 Nanoparticles ◽  
Gravimetric Analysis ◽  
Nanocomposite Membranes ◽  
Solid Superacids ◽  
Proton Conducting ◽  
Fuel Cell Performance

To investigate the effect of acidic nanoparticles on proton conductivity, permeability, and fuel-cell performance, a commercial Nafion® 117 membrane was impregnated with zirconium phosphates (ZrP) and sulfated zirconium (S-ZrO2) nanoparticles. As they are more stable than other solid superacids, sulfated metal oxides have been the subject of intensive research. Meanwhile, hydrophilic, proton-conducting inorganic acids such as zirconium phosphate (ZrP) have been used to modify the Nafion® membrane due to their hydrophilic nature, proton-conducting material, very low toxicity, low cost, and stability in a hydrogen/oxygen atmosphere. A tensile test, water uptake, methanol crossover, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), and scanning electron microscopy (SEM) were used to assess the capacity of nanocomposite membranes to function in a fuel cell. The modified Nafion® membrane had a higher water uptake and a lower water content angle than the commercial Nafion® 117 membrane, indicating that it has a greater impact on conductivity. Under strain rates of 40, 30, and 20 mm/min, the nanocomposite membranes demonstrated more stable thermal deterioration and higher mechanical strength, which offers tremendous promise for fuel-cell applications. When compared to 0.113 S/cm and 0.013 S/cm, respectively, of commercial Nafion® 117 and Nafion® ZrP membranes, the modified Nafion® membrane with ammonia sulphate acid had the highest proton conductivity of 7.891 S/cm. When tested using a direct single-cell methanol fuel cell, it also had the highest power density of 183 mW cm−2 which is better than commercial Nafion® 117 and Nafion® ZrP membranes.

Microstructures and Mechanical Properties of Annealed Fe-8Mn-6Al-0.4C Duplex Low-Density Steels

2021 ◽  
Vol 1035 ◽  
pp. 337-343
Author(s):  
Rong Chen ◽  
Peng Chen ◽  
Xiao Wu Li
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Mechanical Stability ◽  
Volume Fraction ◽  
Electron Back Scatter Diffraction ◽  
Low Density ◽  
X Ray Diffraction ◽  
Austenite Grain Size ◽  
The Stability

The cold-rolled Fe-8Mn-6Al-0.4C duplex low-density steel was annealed at different conditions to obtain ferrite + austenite duplex microstructure. The excellent mechanical properties (i.e., elongation of 52%, tensile strength of 785 MPa, and a product of tensile strength and elongation of 40.9 GPa·%) have been obtained by adjusting the volume fraction and the stability of austenite. The microstructure of the experimental steels was analyzed by scanning electron microscopy (SEM) and electron back-scatter diffraction (EBSD), and the volume fraction of austenite was estimated by the X-ray diffraction (XRD). The results show that the distribution of austenite grain size is inhomogeneous, and that the mechanical stability of austenite is mainly affected by the alloying partitioning and the variation of grain size during the annealing process. The increase of elongation is attributed to the degradation in mechanical stability of austenite, which can efficiently promote an occurrence of transformation induced plasticity (TRIP) effect.

scholarly journals In Situ Evaluation of the Influence of Interstitial Oxygen on the Elastic Modulus of La2NiO4

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1889
Author(s):  
Yuta Kimura ◽  
Takashi Nakamura ◽  
Koji Amezawa ◽  
Keiji Yashiro ◽  
Tatsuya Kawada
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Oxygen Concentration ◽  
Elastic Moduli ◽  
Mechanical Stability ◽  
Young's Modulus ◽  
Resonance Method ◽  
Lattice Defects ◽  
Interstitial Oxygen

Lattice defects significantly affect the mechanical properties of crystalline metal oxides. The materials for the components of solid oxide fuel cells (SOFCs) are no exception, and hence understanding of the interplay between lattice defects and the mechanical properties of components is important to ensure the mechanical stability of SOFCs. Herein, we performed an in situ evaluation of the temperature and P(O2) dependence of the elastic moduli of La2NiO4 (LN214), a candidate for the cathode material of SOFCs, using the resonance method to understand the influence of interstitial oxygen on its elastic properties. Above 873 K, both the Young’s and shear moduli of LN214 slightly decreased with increasing P(O2), suggesting that these elastic moduli are correlated with interstitial oxygen concentration and decreased with increasing interstitial oxygen. We analyzed the influence of interstitial oxygen on the Young’s modulus of LN214, based on numerically obtained lattice energy. The P(O2) dependence of the Young’s modulus of LN214 was found to be essentially explained by variation in the c-lattice constant, which was triggered by variation in interstitial oxygen concentration. These findings may contribute to a better understanding of the relationship between lattice defects and mechanical properties, and to the improvement of the mechanical stability of SOFCs.

scholarly journals Coordination polymer glass from a protic ionic liquid: proton conductivity and mechanical properties as an electrolyte

2020 ◽  
Vol 11 (20) ◽  
pp. 5175-5181 ◽  
Author(s):  
Tomohiro Ogawa ◽  
Kazuki Takahashi ◽  
Sanjog S. Nagarkar ◽  
Koji Ohara ◽  
You-lee Hong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Ionic Liquid ◽  
Fuel Cell ◽  
Coordination Polymer ◽  
Solid Electrolyte ◽  
Proton Conductivity ◽  
Protic Ionic Liquid ◽  
Proton Conducting ◽  
Polymer Glass

A proton-conducting coordination polymer glass derived from a protic ionic liquid works as a moldable solid electrolyte and the anhydrous fuel cell showed I–V performance of 0.15 W cm−2 at 120 °C.

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