Graphitized carbon membrane

In a related approach, these same porous alumina membranes serve as a mask through which O2 plasmas are used to etch underlying carbon films. This etching process produces honeycomb carbon structures that are positive replicas of the alumina-membrane mask. This process has successfully produced honeycomb structures of both diamond and graphitic carbon, with pore sizes in the carbon replica around 70 nm. 

LC techniques are widely diffused for the determination of hydrophilic but not volatile and thermally unstable pesticides. Since the European Community Directive [68] indicates 0.1 pg L" as the concentration threshold level for a single pesticide in waters destined for human consumption, to quantify these concentration levels, suitable pre-concentration and extraction procedures must be generally performed prior to the HPLC determination. The extraction methods are based on LLE, MAE, on-line continuous flow liquid membrane extraction (CFLME), and mainly on SPE and SPME. Many SPE procedures are used the packing materials are graphitized carbon, ODS, styrene-divinylbenzene co-polymers, or selective phases based on immunoafflnity. The extraction can be performed on- and off-line, manually, or in a semi-automated way. 

It is interesting to note that conventional carbon black supports promote the formation of peroxide, which then decomposes into radicals that attack the membrane. However, the role of graphitized carbon materials (such as CNTs) in peroxide formation is less clear. Smalley suggested that the curvy graphitic structure of CNTs deactivates free radicals by stabilizing them through enhanced delocalization. It would be worthwhile to determine whether the formation and fate of peroxide is any different between the carbon black and the CNT. At any rate, it is well known that the rate of formation of peroxide is greatly reduced by elimination of the carbon black support. Evidence of this is clear from the work we have done on carbonless electrodes (PTFE-bonded Pt black electrodes) and those with a hybrid structure. - " ... 

Carbon molecular sieve membranes have been prepared on porous supports by controlled pyrolysis. For example, Chen and Yang [1994] prepar carbon molecular sieve membranes on porous graphite supports by coating a layer of polyfurfuryl alcohol followed by conu-olled pyrolysis with a Hnal temperature of 50O C. The procedure can be repeated to deposit a desired thickness of the carbon membrane. The choice of a graphite support is partially based on the consideration of the compatibility in thermal expansion between the carbon and the support. 

Reduction of carbon dioxide to graphite carbon via methane by catalytic fixation with membrane reactor... 

Graphite membranes are obtained by drying a graphitic oxide gel on a polished surface, reducing with hydrogen at temperatures above 500°C and graphitizing the carbon membrane formed at temperatures above 2500°C. 

The discrepancies with the HPLC method are probably due to the imperfect nature of the C18-silica columns. Some of the new-generation reverse-phase materials, such as C18-alumina, polymeric C18, ultra-high carbon-loaded CT8, and porous graphitic carbon may overcome these problems. A recent development is an immobilized artificial membrane (lAM) column, which should more closely model the biological membranes. 

Instead of carbon nanotubes, graphitic carbonized PPV nanotubes prepared in an alumina membrane have been used. Further, nanotubes embedded with gold nanoparticles were used for the fabrication of field emitting devices. " ... 

Carbon constitutes the most abundant element of the different FC components. Setting aside the membrane, which is a polymer with a carbon backbone, all the other components, i.e. the CL, GDL and current collector plates (bipolar plates) are made almost entirely of graphitic carbon. The electrocatalyst support of the CL is commonly carbon black in the form of fine powder. GDLs are thin porous layers formed by carbon fibers interconnected as a web or fabric, while current collector plates are carbon monoliths with low bulk porosity. As explained above each of these components has a particular function within the fuel cell and in particular in the triple phase boundary. The structure and properties of the carbon in each of the different FC components will determine the whole performance of the cell. 

Instead of carbon nanotubes, graphitic carbonized PPV nanotubes prepared in an alumina membrane... 

Semi-dry transfer For the semi-dry transfer, the gel-membrane sandwich is placed between carbon plate electrodes. Semi-dry or horizontal blotting uses two plate electrodes (stainless steel or graphite/ carbon) for a uniform electrical field over a short distance, and sandwiches between these of up to six gel/membrane/filter paper assemblies, all well soaked in transfer buffer. The assembly is clamped or otherwise secured on its side and electrophoretic transfer effected in this position, using as transfer buffer only the liquid contained in the gel and filter papers or other pads in the assembly. 

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