Perfluorocarbon compounds

S.R. Thomas, L. Gradon, S.E. Pratsinis, R.G. Pratt, G.P. Fotou, A.J. McGoron, A.L. Podgorski, R.W. Millard, Perfluorocarbon compound aerosols for delivery to the lung as potential F magnetic resonance reporters of regional pulmonary p02. Invest. Radiol. 32 (1997) 2 38. 

Use of Perfluorocarbon Compounds to Improve the Cathodic Oxygen Electro-reduction Behavior for Fuel Cell Applications... 

The use of perfluorocarbon compounds as additives to enhance the rate of oxygen reduction at Pt-based electrodes was pursued primarily due to the known high oxygen solubility characteristics. An additional attractive feature of these compounds is their high chemical, electrochemical, and thermal stability. 

Table 1.3 Physical properties, including the oxygen solubility, of a number of promising perfluorocarbon compounds.

These results suggest that when the electrocatalytic zone is completely immersed in the perfluorocarbon fluid the diffusion of the reactants and/or products to the catalyst site is impeded by the blocking effect of the additive, which can be described as a flooded system. It is possible that the fluid also interacts with the ionomeric material in the electrocatalytic mixture, decreasing the ability to function as an proton conducting material owing to immiscibility of water with the perfluorocarbon compounds. However, the facility of reaction greatly increases as more of perfluorocarbon exits the system, as shown in Fig. 1.28. These results indicate that the presence of perfluorocarbon fluids have some beneficial effects upon the kinetics of oxygen reduction at Nafion -H-... 

Volatile Organic Compound (VOC), means any compound of carbon, excluding carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates, and ammonium carbonate, which participates in atmospheric photochemical reactions. This includes any such organic compound other than the following, which have been determined to have negligible photochemical reactivity Methane ethane methylene chloride (dichloro-methane) 1.1.1-trichloroethane (methyl chloroform) l.l.l-trichloro-2.2.2-trifluorethane (CFC-113), furthermore cyclic, branched or linear completely methylated siloxanes acetone and perfluorocarbon compounds. 

Although Antoine Lavoisier (1743-1794) had assumed the existence of a new element in hydrofluoric acid, it was not until 1886 when Henri Moissan (1852-1907) succeeded in synthesizing elemental fluorine. He electrolysed potassium fluoride dissolved in liquid hydrofluoric acid at —55°C in a platinum apparatus [5], and he was awarded the Nobel Prize for the same in 1906. As Moissan used graphite electrodes, the nascent fluorine reacted with carbon and produced a blend of perfluorocarbon compounds mainly containing tetrafluoromethane, CF4. Moissan noted that what he assumed to be pure CF4 would fiercely react with sodium to give carbon and sodium fluoride [6]. 

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