Carbon blacks electroconductivity

Ketjenblack EC, ED. [Akzo] Carbon black electroconductive carbon black... 

The carbon blacks used in plastics are usually different from the carbon blacks used in mbber. The effect of carbon black is detrimental to the physical properties of plastics such as impact strength and melt flow. Electroconductive grades of carbon black have much higher surface areas than conventional carbon blacks. The higher surface areas result in a three-dimensional conductive pathway through the polymer at much lower additive levels of the carbon black. The additive concentrations of electroconductive carbon blacks is usually j to that of a regular carbon black (132). 

Electroconductive resin compositions, which are useful for packaging electronic devices, have been described. In general, electroconductive resin compositions are made up from a thermoplastic resin and an electroconductive filler, mostly carbon black. Polyphenylene ether) resins are known to impart heat resistance. For general purposes, a poly(styrene) (PS) resin and an ABS resin are superior to other resins in that even if carbon black is incorporated in a large amount, there will be no substantial decrease in the flowability or... 

Concentration of antistats in plastics is mostly 0.1 to 2 %. Special grades of electroconducting (EC) carbon black are used in PO at levels higher than 10 % (Accorsi and Yu, 1998). Other conducting fillers incorporating antistatic effects, such as metals or organic semiconductors (e.g. polypyrrole) are not commonly used in plastics for contact with food. 

There are many ways to eliminate surface electrostatic, for example, by increasing the humidity or the conductivity of the surrounding atmosphere, or by increasing the electric conductance of materials with the use of electroconducting carbon blacks, powdered metals, or antistatic agents. 

Electroconducting carbon blacks are largely utilized to increase the electric conductivity of organic polymers. The electric conductivity of carbon blacks depends, inter aha, on the capacity to form branched structures in the polymer matrix, and on the size and size distribution of carbon black particles. The branched and tentacular structures of carbon in the polymer matrix are responsible for the electric conductivity, as is the case for lamp, acetylene, and furnace carbon blacks. The specific resistance of the carbon particles decreases with their size and then increases with further diminution of the size. A wide size distribution is believed to favor the formation of branched structures contributing to greater conductivity. 

In spite of the effectiveness of some carbon blacks in reducing surface charges on plastics materials, the use of antistatic agents have increased steadily. The simplest antistatic agent is water. It is adsorbed on the surface of objects exposed to a humid atmosphere, and it forms a thin electroconducting layer with impurities adsorbed from the air. Such a layer is even formed on the surface of hydrophobic plastics, probably because of the existence of a thin layer of dirt. 

The inclusion of the PRU grains in the bulk of the lead skeleton branches indicates that this carbon black type has high affinity to lead. During formation of the negative active material, the carbon particles are adsorbed on the lead surface of the growing lead branch. As these particles are electroconductive, the electrochemical reaction of lead ion reduction proceeds on their surface. The newly formed lead surrounds the carbon grains and thus the latter are incorporated into the bulk of the lead branch of NAM skeleton. 

Very pure superconductive carbon blacks are produced by Akzo Nobel under the name Ketjenblack. Due to their unique morphology, substantially lower amounts can be used compared with conventional blacks, giving improved processing and mechanical properties for electroconductive products. 

Electroconducting carbon blacks are largely utilized to increase the electric conductivity of organic polymers. The electric conductivity of carbon blacks depends on the following items ... 

The composition and the chemical structure of the surfaces of carbon blacks, since they can fix substances by chemical adsorption, thus creating insulating layers between particles. This makes impossible the formation of electroconducting structures. To prevent this problem the surface of the carbon black particles is cleaned by heat treatments in vacuum or in an inert atmosphere at 2000°C. 

Recently, high performance LiMno.8Feo.2PO4 was prepared with both etched and functionalized multi-walled CNTs and ketjenblacks (52). Ketjenblack is an electroconductive carbon black from AKZO Chemicals B.V. Corp. In detail, the preparation was done as follows (52) ... 

Moreover, the use of multi-walled CNTs together with Ketjen-blacks showed better electrochemical performance than when Ket-jenblacks or multi-walled CNTs were used separately (52). Ket-jenblacks are electroconductive carbon black powders with high surface areas, available from AkzoNobel. 

Ketjenblack EC-300J is a carbon black having a unique morphology. It is extreamly suitable for electroconductive applications. Due to its structure only one third the amount of Ketjenblack EC-300J is needed cogqtared to conventional carbon blacks in many applications. Ketjenblack EC-300J is especially useful in applications requiring low ash and is recommended for use in material which must have a smooth surface. 

The selection of materials and fabrication techniques is crucial for an adequate sensor function and the performance of a sensor often ultimately depends upon these factors. Consequently, future developments in sensor design will inevitably focus upon the technology of new materials. Materials used in electrochemical sensors are classified as (1) materials for the electrode and supporting substrate (metals platinum, gold, silver, and stainless steel carbon-based materials graphite, carbon black, and carbon fibre new mixed materials or organic electroconductive... 

Conductive polymers, such as polyacetylene, polythiophene, polypyrrole, polyisothianaphthene, polyethylene dioxythiophene, polyaniUne, and so on, have interesting properties that make them suitable for use in PEMFCs (Heeger, 2001 Shirakawa, 2001). Their electroconductivity and noncarbon functionalities allow some of them to perform effectively as alternative carbon catalysts or with carbon supports to enhance their catalytic effects. Huang et al. utilized polypyrrole as a conductive polymer support for a platinum catalyst active for the ORR (Huang et al., 2009). Their results show significant resistance to carbon corrosion and improved conductivity over traditional Pt/C catalysts. They report that the platinum on polypyrrole catalyst (Pt/Ppy) has well-dispersed platinum particles of about 3.6 nm in diameter. CV scans up to 1.8 V revealed that there was httle carbon support corrosion on the Pt/Ppy and a twofold increase in activity than Pt black at 0.9 V. 

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