Tetrachloroethylene | EPFL Graph Search

Tetrachloroethylene, also known under the systematic name tetrachloroethene, or perchloroethylene, and abbreviations such as "perc" (or "PERC"), and "PCE", is a chlorocarbon with the formula Cl2C=CCl2. It is a colorless liquid widely used for dry cleaning of fabrics, hence it is sometimes called "dry-cleaning fluid". It also has its uses as an effective automotive brake cleaner. It has a mild sweet odor, similar to the smell of chloroform, detectable by most people at a concentration of 1 part per million (1 ppm). French chemist Henri Victor Regnault first synthesized tetrachloroethylene in 1839 by thermal decomposition of hexachloroethane following Michael Faraday's 1820 synthesis of protochloride of carbon (carbon tetrachloride). C2Cl6 → C2Cl4 + Cl2 Faraday was previously falsely credited for the synthesis of tetrachloroethylene, which in reality, was carbon tetrachloride. While trying to make Faraday's "protochloride of carbon", Regnault found that his compound was different from Faraday's. Victor Regnault stated "according to Faraday, the chloride of carbon boiled around to degrees Celsius but mine did not begin to boil until ". Tetrachloroethylene can be made by passing chloroform vapour through a red-hot tube, the side products include hexachlorobenzene and hexachloroethane, as reported in 1886. Most tetrachloroethylene is produced by high temperature chlorinolysis of light hydrocarbons. The method is related to Faraday's method since hexachloroethane is generated and thermally decomposes. Side products include carbon tetrachloride, hydrogen chloride, and hexachlorobutadiene. Several other methods have been developed. When 1,2-dichloroethane is heated to 400 °C with chlorine, tetrachloroethylene is produced by the chemical reaction: ClCH2CH2Cl + 3 Cl2 → Cl2C=CCl2 + 4 HCl This reaction can be catalyzed by a mixture of potassium chloride and aluminium chloride or by activated carbon. Trichloroethylene is a major byproduct, which is separated by distillation. Worldwide production was about in 1985.

Effect of Native Oxide on Stress in Silicon Nanowires: Implications for Nanoelectromechanical Systems

Yusuf Leblebici, Zuhal Tasdemir, Mohammad Nasr Esfahani

Understanding the origins of intrinsic stress in Si nanowires (NWs) is crucial for their successful utilization as transducer building blocks in next-generation, miniaturized sensors based on nanoelectromechanical systems (NEMS). With their small size lead ...

AMER CHEMICAL SOC2022