Electrostatic assist process

This paper gives an outline of one of the most successful applications of electrostatic techniques in an existing production process, namely, the electrostatic assist process for ink transfer in gravure printing. 

The electrostatic assist process was developed to overcome a specific print defect which had plagued printers and paper makers for years, namely, skipped dots. 

Other processes investigated for planar SOFC fabrication include electrostatic-assisted vapour deposition, vapour phase electrolytic deposition, vacuum evaporation, laser spraying, transfer printing, sedimentation method, and plasma metal organic chemical vapour deposition. 

In plasma-assisted CVD, an electrostatically or electromagnetically induced plasma discharge is carried out in a low pressure system. The result is that the process may be operated at a considerably lower temperature. This has been employed in the deposition of SiOj and Si3N4 in the production of heat-sensitive microelectronic circuits. 

Other groups have achieved CNT forest assemblies by electrostatic SWNT-COO / Fe interactions also starting with shortened CNTs. The assembly process involves sequential substrate dipping in dilute Nafion and aqueous FeCl3 solutions followed by DMF-assisted precipitation of the nafion-adsorbed Fe to produce thin FeO(OH)/FeOCl nanocrystals. Subsequent immersion into a DMF disperse nanotube suspension produces the forest assembly that is driven by acid-base neutralization [12, 61, 121[. 

Once the dirty spot is removed from the substrate being laundered, it is important that it not be redeposited. Solubilization of the detached material in micelles of surfactant has been proposed as one mechanism that contributes to preventing the redeposition of foreign matter. Any process that promotes the stability of the detached dirt particles in the dispersed form will also facilitate this. We see in Chapter 11 how electrostatic effects promote colloidal stability. The adsorption of ions —especially amphipathic surfactant ions —onto the detached matter assists in blocking redeposition by stabilizing the dispersed particles. Materials such as carbox-ymethylcellulose are often added to washing preparations since these molecules also adsorb on the detached dirt particles and interfere with their redeposition. 

Electrofining a process for contacting a light hydrocarbon stream with a treating agent (acid, caustic, doctor, etc.), then assisting the action of separation of the chemical phase from the hydrocarbon phase by an electrostatic field. 

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