Solid State Ionics Research Papers (original) (raw)

Ionic groups incorporated into a polymer have a decided effect on its physical properties. A number of ionomers and polyelectrolytes have been widely applied. In particular, sulfonated bisphenol-A polysulfone (SPSF) has been used as a... more

Ionic groups incorporated into a polymer have a decided effect on its physical properties. A number of ionomers and polyelectrolytes have been widely applied. In particular, sulfonated bisphenol-A polysulfone (SPSF) has been used as a composite or single-component membrane for the desalination of water. In this article, the synthesis and physical characteristics of sulfonated polysulfone are addressed. A detailed synthesis route is provided and methods that yield determinable levels of sulfonation are described. These ion-containing polymers retain an excessive amount of residual salts, which, of course, are impurities to the system. Therefore, before any analyses were made the polymers were subjected to a thorough soxhlet extraction process with boiling water, which appeared to be quite effective. The degree of sulfonation was assessed by several methods such as 1H NMR and FT-IR. A new 1H NMR method was derived because the method cited in the literature proved to be too inconsistent for our work. The new 1H NMR method used a quaternary ammonium counterion [N(CH3)4]. These methyl protons are easily measured and may be ratioed against the isopropylidene protons in the polymer backbone that act as an internal standard. Characterization of the physical properties of SPSF consisted of water uptake, differential scanning calorimetry (DSC), thermomechanical analysis (TMA), and solubility studies. Its physical appearance and mechanical behavior were improved by the solution procedure. Also addressed were the effects of different counterions (Na+ & Mg++) with SPSFs of low levels of sulfonation. The variation in physical properties between the divalent and monovalent counterions is dramatic, especially when observed by TMA in the rubber plateau above the apparent glass temperature.

A conductivity relaxation experiment has been conducted on an SrFeCo0.5Ox sample by abruptly changing the oxygen partial pressure in the atmosphere and monitoring the change of conductivity as a function of time. The re-equilibrium... more

A conductivity relaxation experiment has been conducted on an SrFeCo0.5Ox sample by abruptly changing the oxygen partial pressure in the atmosphere and monitoring the change of conductivity as a function of time. The re-equilibrium process obeys Fick's second law. By fitting the relaxation data to the solution of the diffusion equation with appropriate boundary conditions, we could determine the oxygen chemical diffusion coefficient and the activation energy. The oxygen diffusion coefficient is 8.9 × 10−7 cm2/s at 900 °C and it increases with increase in temperature. Measured activation energy is 0.92 eV, which is slightly lower than that of other oxides in the system SrFe1 − xCoxOy.

The synthesis, structure, and physical properties of five R-type Ru ferrites with chemical formula BaMRu5O11 (M=Li and Cu) and BaM‧2Ru4O11 (M‧=Mn, Fe and Co) are reported. All the ferrites crystallize in space group P63/mmc and consist of... more

The synthesis, structure, and physical properties of five R-type Ru ferrites with chemical formula BaMRu5O11 (M=Li and Cu) and BaM‧2Ru4O11 (M‧=Mn, Fe and Co) are reported. All the ferrites crystallize in space group P63/mmc and consist of layers of edge sharing octahedra interconnected by pairs of face sharing octahedra and isolated trigonal bipyramids. For M=Li and Cu, the ferrites are paramagnetic metals with the M atoms found on the trigonal bipyramid sites exclusively. For M‧=Mn, Fe and Co, the ferrites are soft ferromagnetic metals. For M‧=Mn, the Mn atoms are mixed randomly with Ru atoms on different sites. The magnetic structure for BaMn2Ru4O11 is reported.

An effective, dense and well adherent coating was produced on 430SS that has the result of significantly reducing the oxidation rate of this alloy at elevated temperatures. The coating is essentially a Mn–Co–O spinel, applied in powder... more

An effective, dense and well adherent coating was produced on 430SS that has the result of significantly reducing the oxidation rate of this alloy at elevated temperatures. The coating is essentially a Mn–Co–O spinel, applied in powder form, and compacted to improve its ...