scholarly journals Crystal Structures of Mixed-Conducting Oxides Present in The Sr-Fe-Co-O System

1997 ◽  
Vol 496 ◽  
Author(s):  
J. P. Hodges ◽  
J. D. Jorgensen ◽  
D. J. Miller ◽  
B. Ma ◽  
U. Balachandran ◽  
...  
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Elevated Temperatures ◽  
Ceramic Membranes ◽  
Rechargeable Batteries ◽  
Quantitative Phase Analysis ◽  
Ceramic Oxides ◽  
Conducting Oxides ◽  
Oxidation Of Methane ◽  
Dense Ceramic ◽  
Potential Applications

ABSTRACTThe potential applications of mixed-conducting ceramic oxides include solid-oxide fuel cells, rechargeable batteries, gas sensors and oxygen-permeable membranes. Several perovskite-derived mixed Sr-Fe-Co oxides show not only high electrical-conductivity but also appreciable oxygen-permeability at elevated temperatures. For example, dense ceramic membranes of SrFeCo0.5O3-δ can be used to separate oxygen from air without the need for external electrical circuitry. The separated oxygen can be directly used for the partial oxidation of methane to produce syngas. Quantitative phase analysis of the SrFeCo0.5O3-δ material has revealed that it is predominantly composed of two Sr-Fe-Co-O systems, Sr4Fe6-xCoxO13 and SrFe1−xCoxO3-δ. Here we report preliminary structural findings on the SrFe1−xCoxO3-δ (0 ≤ x ≥ 0.3) system.

scholarly journals Phase Stability of The Mixed-Conducting Sr-Fe-Co-O System

1997 ◽  
Vol 496 ◽  
Author(s):  
B. Ma ◽  
U. Balachandran ◽  
J. P. Hodges ◽  
J. D. Jorgensen ◽  
D. J. Miller ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Elevated Temperatures ◽  
Cobalt Content ◽  
Ceramic Membranes ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Ceramic Oxides ◽  
Partial Pressures ◽  
Dense Ceramic ◽  
Increasing Temperature

ABSTRACTMixed-conducting ceramic oxides have potential uses in high-temperature electrochemical applications such as solid oxide fuel cells, batteries, sensors, and oxygen-permeable membranes. The Sr-Fe-Co-O system combines high electronic/ionic conductivity with appreciable oxygen permeability at elevated temperatures. Dense ceramic membranes made of this material can be used to separate high-purity oxygen from air without the need for external electrical circuitry, or to partially oxidize methane to produce syngas. Samples of Sr2Fe3-xCoxOy (with x = 0,0.6,1.0, and 1.4) were prepared by solid-state reaction method in atmospheres with various oxygen partial pressures (pO2) and were characterized by X-ray diffraction, scanning electron microscopy, and electrical conductivity testing. Phase components of the sample are dependent on cobalt concentration and pO2. Electrical conductivity increases with increasing temperature and cobalt content in the material.

Dense ceramic membranes based on ion conducting oxides

2007 ◽  
Vol 32 (2) ◽  
pp. 197-212 ◽  
Author(s):  
Marie-Laure Fontaine ◽  
Yngve Larring ◽  
Truls Norby ◽  
Tor Grande ◽  
Rune Bredesen
Keyword(s):  
Ceramic Membranes ◽  
Conducting Oxides ◽  
Dense Ceramic ◽  
Ion Conducting

Dense ceramic membranes for partial oxidation of methane to syngas

1995 ◽  
Vol 133 (1) ◽  
pp. 19-29 ◽  
Author(s):  
U. Balachandran ◽  
J.T. Dusek ◽  
R.L. Mieville ◽  
R.B. Poeppel ◽  
M.S. Kleefisch ◽  
...  
Keyword(s):  
Partial Oxidation ◽  
Ceramic Membranes ◽  
Partial Oxidation Of Methane ◽  
Oxidation Of Methane ◽  
Dense Ceramic

Ultra-Thin Flexible Ceramic Membranes for Electronic Applications

2013 ◽  
Vol 2013 (1) ◽  
pp. 000379-000383
Author(s):  
John A. Olenick
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Thermal Shock ◽  
Elevated Temperatures ◽  
Ceramic Membranes ◽  
Oxygen Sensors ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Stabilized Zirconia ◽  
Gas Tight

In 2010, ENrG Incorporated commercialized 40 microns thick, flexible zirconia based ceramic membranes as shown in Figure 1. Even though so thin, the membranes are gas-tight, fully dense, strong, thermal shock tolerant and chemically inert. Historically, zirconia membranes are used mainly for applications such as solid oxide fuel cells and oxygen sensors, making use of the ionic property of partially stabilized zirconia at elevated temperatures.

Development of Mixed-Counducting Ceramics For Gas Separation Applications

1998 ◽  
Vol 548 ◽  
Author(s):  
U. Balachandran ◽  
B. Ma ◽  
P.S. Maiya ◽  
J.T. Dusek ◽  
J.J. Picciolo ◽  
...  
Keyword(s):  
Gas Separation ◽  
Hydrogen Permeation ◽  
Electronic Conductivity ◽  
Ionic Conductivities ◽  
Ceramic Membranes ◽  
Oxygen Flux ◽  
Membrane Thickness ◽  
Conducting Oxides ◽  
Separation Membranes ◽  
Oxidation Of Methane

ABSTRACTMixed-conducting oxides are used in many applications, including fuel cells, gas separation membranes, sesors, and electrocatalysis. This paper describes mixed-conducting ceramic membranes that are being developed to selectively remove oxygen and hydrogen from gas streams in a nongalvanic mode of operation (i.e., with no electrodes or external power supply). Because of its high combined electronic/ionic conductivity and significant oxygen permeability, the mixed-coducting Sr-Fe-Co oxide (SFC) has been developed for high-purity oxygen separation and/or partial oxidation of methane to synthesis gas, i.e., syngas, a mixture of carbon monoxide and hydorgen. The electronic and ionic conductivities of SFC were found to be comparable in magnitude are presented as a function of temperature. The oxygen flux through dense SFC tubes during separation of oxygen from air is compared with the oxygen flux during methane conversion.Unlike SFC, in which the ionic and electronic conductivities are nearly equivalent, BaCe0.80Y0.20O3 (BCY) exhibits protonic conductivity that is significantly higher that its electronic coductivity. To enhance the electronic conductivity and increase hydrogen permeation, metal powder was combined with the BCY to form a cermet membrane. Nongalvanic permeation of hydrogen through the cermet memebrane was demonstrated and characterized as a function of membrane thickness. A sintering aid was developed to avoid interconnected porosity in and improve the mechanical properties of the cermet membrane.

Dense Ceramic Membranes for Separation and Reaction

2007 ◽  
Vol 1 (3) ◽  
pp. 228-237
Author(s):  
Zhentao Wu ◽  
Kang Li
Keyword(s):  
Ceramic Membranes ◽  
Dense Ceramic

scholarly journals Preparation and Properties of Electrospun Phenylethynyl—Terminated Polyimide Nano-Fibrous Membranes with Potential Applications as Solvent-Free and High-Temperature Resistant Adhesives for Harsh Environments

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1525
Author(s):  
Hao-ran Qi ◽  
Deng-xiong Shen ◽  
Yan-jiang Jia ◽  
Yuan-cheng An ◽  
Hao Wu ◽  
...  
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Elevated Temperatures ◽  
Solvent Free ◽  
High Tech ◽  
Molecular Weights ◽  
Lap Shear ◽  
High Adhesion ◽  
Potential Applications ◽  
Fibrous Membranes

High-temperature-resistant polymeric adhesives with high servicing temperatures and high adhesion strengths are highly desired in aerospace, aviation, microelectronic and other high-tech areas. The currently used high-temperature resistant polymeric adhesives, such as polyamic acid (PAA), are usually made from the high contents of solvents in the composition, which might cause adhesion failure due to the undesirable voids caused by the evaporation of the solvents. In the current work, electrospun preimidized polyimide (PI) nano-fibrous membranes (NFMs) were proposed to be used as solvent-free or solvent-less adhesives for stainless steel adhesion. In order to enhance the adhesion reliability of the PI NFMs, thermally crosslinkable phenylethynyl end-cappers were incorporated into the PIs derived from 3,3’,4,4’-oxydiphthalic anhydride (ODPA) and 3,3-bis[4-(4-aminophenoxy)phenyl]phthalide (BAPPT). The derived phenylethynyl-terminated PETI-10K and PETI-20K with the controlled molecular weights of 10,000 g mol−1 and 20,000 g mol−1, respectively, showed good solubility in polar aprotic solvents, such as N-methyl-2-pyrrolidinone (NMP) and N,N-dimethylacetamide (DMAc). The PI NFMs were successfully fabricated by electrospinning with the PETI/DMAc solutions. The ultrafine PETI NFMs showed the average fiber diameters (dav) of 627 nm for PETI-10K 695 nm for PETI-20K, respectively. The PETI NFMs showed good thermal resistance, which is reflected in the glass transition temperatures (Tgs) above 270 °C. The PETI NFMs exhibited excellent thermoplasticity at elevated temperatures. The stainless steel adherends were successfully adhered using the PETI NFMs as the adhesives. The PI NFMs provided good adhesion to the stainless steels with the single lap shear strengths (LSS) higher than 20.0 MPa either at room temperature (25 °C) or at an elevated temperature (200 °C).

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