Reduction In Formation Rate Research Articles

Composite Gel Polymer Electrolyte for Improved Cyclability in Lithium-Oxygen Batteries.

Gel polymer electrolytes (GPE) and composite GPE (cGPE) using one-dimensional glass microfillers have been developed for their use in lithium-oxygen batteries. Using glass microfillers, tetraglyme solvent, UV-curable polymer, and lithium salt at various concentrations, the preparation of cGPE yielded free-standing films. These cGPEs, with 1 wt % of microfillers, demonstrated increased ionic conductivity and lithium transference number over GPEs at various concentrations of lithium salt. Improvements as high as 50% and 28% in lithium transference number were observed for 0.1 and 1.0 mol kg-1 salt concentrations, respectively. Lithium-oxygen batteries containing cGPE similarly showed superior charge/discharge cycling for 500 mAh g-1 cycle capacity with as high as 86% and 400% increase in cycles for cGPE with 1.0 and 0.1 mol kg-1 over GPE. Results using electrochemical impedance spectroscopy, Raman spectroscopy, and scanning electron microscopy revealed that the source of the improvement was the reduction of the rate of lithium carbonates formation on the surface of the cathode. This reduction in formation rate afforded by cGPE-containing batteries was possible due to the reduction of the rate of electrolyte decomposition. The increase in solvated to paired Li+ ratio at the cathode, afforded by increased lithium transference number, helped reduce the probability of superoxide radicals reacting with the tetraglyme solvent. This stabilization during cycling helped prolong the cycling life of the batteries.

Effect of a novel induction food‐processing device in improving frying oil quality

SummaryProducing quality fried snacks involves monitoring the chemical processes that occur during frying to control oil degradation. Our objective was to evaluate the effects of a Novel Induction Food‐Processing Device (NIFPD) on the quality indices of frying oil. Under standard frying conditions, vegetable oil samples (corn and canola) were collected during a standardised frying cycle to test oxidative stability. Fourier transform infrared spectroscopy was used to evaluate and classify samples during the frying time, and standard reference methods used to monitor the oil stability included p‐anisidine value, free fatty acid content and CIELAB colour. The induction technology decreased the rate of free fatty acid and aldehyde formation. Tests also showed a marked effect on total colour difference between control and treatment (NIFPD), reducing colour degradation. Overall, our results showed that a patented induction device slows the rate of lipid degradation, resulting 7–20% reduction in formation rate of key quality parameters and significantly longer utilisation of frying oil.

Silicidation and carburization of the tungsten filament in HWCVD with silacyclobutane precursor gases

Study of the tungsten filament alloying processes with different precursor molecules shows that silicidation occurs when using silacycobutane (SCB) and carburization with 1,1,3,3-tetramethyl-1,3-disilacyclobutane (TMDSCB). The difference in the decomposition chemistry with the two molecules is responsible for the observation. Comparison of the depth profile and temperature distribution of the Si or C content in the alloyed filament illustrates the interplay among the Si or C deposition onto, evaporation from, and diffusion into the filament. Examination of the time distribution of key products from secondary gas-phase reactions at various filament temperatures demonstrates that gas-phase reactions dominate only at low temperatures. Silicidation or carburization is the dominant process at high temperatures, which contributes to a large consumption rate of precursor gas and a reduction in formation rate of the gas-phase reaction products.