Novel Chemistry for Ethylene and Tin

LifeSciencesWorld: "New work by chemists at UC Davis shows that ethylene, a gas that is important both as a hormone that controls fruit ripening and as a raw material in industrial chemistry, can bind reversibly to tin atoms. The research, published Sept. 25 in the journal Science, could have implications for understanding catalytic processes.

Ethylene has long been known to react with transition metals such as iron or copper, but was not thought to react reversibly with metals such as tin or aluminum, said Philip Power, professor of chemistry at UC Davis and senior author on the paper.

“Reversibility is important, because it shows that it could be involved in catalytic processes,” Power said."

Power did not foresee an immediate application for the discovery, but said that it would contribute in general to understanding ethylene catalysis. Some plants release ethylene to control fruit ripening, although no known biological molecules include a tin atom. There could be implications for industrial catalysis if similar behavior could be shown for a cheap metal like aluminum, he said

Tin Whisker Growth on the Surface of Sn-0.7Cu Lead-Free Solder with a Rare Earth (Nd) Addition

Scopus "The phenomenon of rare earth (RE) additions inducing whisker growth in Sn-0.7Cu-Nd (0.1-5wt.%Nd) solder is reported.

The results showed that Nd exists as Sn3Nd in the microstructure of the solder alloys. A snowflake-like Sn3Nd was observed when Nd≤0.5wt.%. After exposure to ambient conditions, the Nd-bearing alloys have a strong tendency toward whisker growth, with a short incubation time for whisker nucleation (only several hours). All whiskers originated from the Sn-Nd compound, where whiskers grew relatively fast; the average growth rate of the five longest whiskers was approximately 4/s, and a 190μm whisker was observed within 480h.

Based on these results, it was predicted that whisker growth would be inevitable for all RE-bearing solders. The cause of this phenomenon is also discussed. Finally, the authors suggest that any solders doped with RE should be carefully considered again"

Fabrication and characterization of tin nanorod electrodes for lithium ion rechargeable ba

Scopus: "One of the most important problems in utilizing a pure tin anode for lithium ion rechargeable batteries is its poor cyclability due to mechanical fatigue caused by volume changes during lithium insertion and extraction processes. To overcome this problem, tin nanorod electrodes were fabricated by an anodic aluminum oxide (AAO) template-assisted growth method.

The structural and electrochemical properties of the tin nanorod electrode were examined using scanning electron microscopy, X-ray diffraction, cyclic voltammetry, and galvanostatic cycling. Scanning electron microscopic observations revealed that the copper substrate was covered with uniformly distributed tin nanorods with average diameters of about 250 nm.

Electrochemical test results showed that the capacity retention and the rate capabilities of the tin nanorod electrodes were better than those of the planar electrodes. At the tenth cycle, the capacity of the tin nanorod electrode at the C/10 rate still remained 80% of that of the first cycle. Even at the 1C rate, the capacities remained larger than 540 mAhg-1"