Mixed Ionic and Electronic Conduction in Li_3PO_4 Electrolyte for a CO_2 Gas Sensor

An electrochemical CO_2 gas sensor using Li_2CO_3 and Li_2TiO_3+TiO_2 as sensing and reference electrodes, respectively, and Li_3PO_4 as the electrolyte is the subject of this paper. The sensor response to CO_2 gas showed a systematic deviation from the prediction of the Nernst equation at low pCO_2. Based on the electromotive force (emf) measurement, the transference numbers of Li_3PO_4, a lithium-ion conductor, were estimated for different pCO_2 values, and the conduction domain boundary for Li_3PO_4 separating n-type electronic conduction from ionic conduction was constructed. The conduction domain predicts that change in the Li activity in the sensing side of the cell drives the Li_3PO_4 electrolyte to a mixed (n-type electronic and ionic) conduction region at low pCO_2. Hebb-Wagner dc polarization measurements also indicate n-type electronic conduction in Li_3PO_4 with a mixture of Li_2CO_3 and gold as a reversible electrode. The transference numbers obtained from both the emf measurement and the Hebb-Wagner polarization measurements demonstrate that the origin of the non-Nernstian behavior of the CO_2 sensor is due to the lithium mass transport from the Li_2CO_3-sensing electrode to the Li_3PO_4 electrolyte, resulting in nonstoichiometry of Li_3PO_4 at temperatures above 500°C

Analysis of physical and thermal properties of chiengora fibers

This paper excogitates the potential of an unconventional animal fiber in textile applications. The chiengora fiber taken from dog hair has been chosen for this current study to analyze their chemical, physical, morphological, and thermal properties to explore their usage in textiles. Hairs from five different breeds of dogs namely Labrador, Golden retriever, German shepherd, Pomeranian, and Lhasa apso have been characterized and tested in this study. The research revealed that the chemical, morphological, and thermal properties of the hairs of five breeds are similar to each other. However, marked difference is observed in the physical properties of the fiber such as denier and diameter. It is also found that chiengora fibers have more tenacity than other animal fibers and are very coarser than wool fibers. The X-ray diffraction results reveal that chiengora fibers are having higher crystallinity compared to other animal fibers. Only hairs of Lhasa apso and Pomeranian breed have spinnability characteristics using spinning machines due to their finer denier and higher slenderness ratio and may be spun into yarn to create textile products

A novel in situ method for simultaneous growth of smart material single crystals and thin films

Development of a novel in situ method for simultaneous growth of single crystals and thin films of a smart material spinel is achieved. Material to be grown as metal-incorporated single crystal and thin film was taken as a precursor and put into a bath containing acid as a reaction speed-up reagent (catalyst) as well as a solvent with a metal foil as cation scavenger. By this novel method, zinc aluminate crystals having hexagonal facets and thin films having single crystalline orientation were prepared from a single optimized bath. Properties of both crystals and thin films were studied using an x-ray diffractometer and EDAX. $ZnAl_2O_4$ is a well-known wide bandgap compound semiconductor ($E_g$ = 3.8 eV), ceramic, opto-mechanical and anti-thermal coating in aerospace vehicles. Thus a space gmr technique was found to be a new low cost and advantageous method for in situ and simultaneous growth of single crystals and thin films of a smart material