Graphite foils

Co(TPP) has been demonstrated to act as a catalyst for the electrocarboxylation of benzyl chloride and butyl bromide with CO - to give PhCHiCfOiOCH Ph and Bu0C(0)C(0)0Bu, respectively. The propo.sed mechanism involved Co(TPP)R and [Co(TPP-N-R) as intermediates (the latter detected by spectroscopy) in the catalytic production of free R or R-, which then reacted directly with Co(TPP) precipitated on graphite foil has been successfully used for the determination of organic halides, including DDT and 1,2,3,4,5,6-hexachlorocyclohexane (lindane), to sub-ppm level in aqueous solution. Deoxygenation of the solutions is not required, and the technique is moderately insensitive to the ionic composition of the solution. ... 

UHV is not mandatory in PIXE, and the vacuum shared by the beam-line and specimen chamber is typically 10 6torr. The beam emerging from the accelerator has to be made uniform, while generating the minimum possible X-ray and y-ray background near the Si(Li) detector, and to this end graphite or tantalum collimators are to be preferred. PIXE chambers are often lined with graphite foil. 

Unfortunately, few experimental data have been published regarding these types of diffusion layers. Yazici [65] presented a study in which the graphite foils made by Graftech Inc. were used as cathode diffusion layers in DMFCs. Two foils were used one was made out of 80% expanded graphite and 20% PTFE coated carbon particles to form a porous sheet, and the other was identical to the first except that it was perforated for more permeability with 2,500 tips per square inch (15% open area). 

The second foil showed better performance due to more effective transport of gas and liquid within the DL. In fact, when compared to a CC (ELAT with MPL), this second DL did better, especially at dry conditions. Once the cell temperature was increased from room temperature to 80°C, the difference between the CC and the graphite foil DL was not as obvious. In another study, an expanded graphite foil (100% graphite) was used with an MPL on top of one of its surfaces as the cathode DL in a cylindrical PEMFC [66,67]. 

The dimensions of the stainless-steel micro structured reformer are 75 mm x 45 mm x 110 mm. It consists of a stack of micro structured steel foils coated with catalyst and tempered by heating cartridges in the reactor housing. Laser-cut graphite foils were used to seal the reformer under operating conditions up to 200 °C at a flow rate up to 900 ml min-1 and a residence time of 0.07 s. 

Application field.s for graphite foil and graphite membranes ... 

This enzyme-based biosensor uses glucose oxidase (GO) as a chemical recognition element, and an amperometric graphite foil electrode as the transducer. It differs from the first reported glucose biosensor discussed in the introduction to this chapter in that a mediator, 1,1 -dimethylferricinium, replaces molecular oxygen as the oxidant that regenerates active enzyme. The enzymatic reaction is given in Eq. 7.15, and the electrochemical reaction that provides the measured current is shown in Eq. 7.16. 

For preparation of the GOD electrode a highly porous graphite foil of 1 mm thickness (Union Carbide, USA) is oxidized in air at 100°C. A 0.1 mol/1 l,l -dimethylferrocene solution in toluene is dropped onto the electrode and the solvent allowed to evaporate. GOD is covalently bound to the oxidized carbon surface by carbodiimide coupling and the surface is covered by a polycarbonate membrane of 0.03 pm thickness. Before use, the electrode is conditioned in 7 mmol/1 glucose solution for 10 h with an applied potential of + 160 mV. 

A common means of facilitating sample removal consists of lining the inside of the graphite mold with (1) graphite foils -, (2) pyrolytic carbon ", (3) hexagonal boron nitride ... 

The main focus of this year s effort has been on the deposition and characterization of platinum-ruthenium films of various compositions produced by co-sputtering of the individual elements. The effect of ruthenium deposited by reactive cosputtering has also been studied. The sputtering chamber was modified with a linear drive to be able to produce films on graphite foils, porous carbon structures, and on membranes. Thin films were deposited on graphite foil electrodes and characterized by XRD, XPS, SEM and polarization experiments. 

Figure 2. Cyclic voltammograms of Pt and graphite foil m saturated NMe4Cl-DMSO sweep rate 50 mV s", SCE = saturated calomel electrode (after ref. 7).

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