Particulate films

DLVO part of stability, application to thin films, particulate systems Coagulation kinetics Phase formation Rheology... 

New chemical additives were formnlated to accommodate high-current-density plating. However, this current density offered new challenges at high-current densities, most plating solutions lose throwing power. Another problem that was encountered early on was that the anode film particulates would land on the top side of the panel and eventually create nodulation.This did not occur on the bottom side. 

Several other companies have bulk produced CPs in house, to be marketed as products Milliken Research Corp, Spartanburg, SC, USA, P(Py)-coated textiles for microwave absorption, electrostatic dissipation and related uses Echema Co. has produced conductive electrodes incorporating P(ANi) Bridgestone-Seiko, Japan, and Siemens, Germany, have attempted unsuccessfully to market CP-based batteries BASF, Ludwigshaven, Germany, also attempted unsuccessfully to market several CP (P(Py), P(ANi)) products such as films, particulate fillers and batteries Matsushita Co., Higashimita, Japan, apparently still markets P(Py)-based Al-electrolytic... 

Particulate contamination (including surface inclusions and irregularities) is a major source of pinholes in deposited films. Particulates can be removed by the techniques discussed previously but can present special problems for cleaning. The ability to remove particles from a surface depends on the size, shape, and composition of the particle as well as the surface to which it adheres. Particulate contamination can be removed by several mechanisms. 

In the case of Co—Cr having perpendicular anisotropy there is, in principle, a competition between the uniaxial anisotropy of a hexagonal stmcture and the demagnetizing energy of the thin film. In the case of magnetically separated Co—Cr columns (particulate morphology) then also the shape anisotropy contributes to the perpendicular anisotropy. 

Because the corrosion resistance of lead and lead alloys is associated with the formation of the protective corrosion film, removal of the film in any way causes rapid attack. Thus the velocity of a solution passing over a surface can lead to significantly increased attack, particularly if the solution contains suspended particulate material. Lead is also attacked rapidly in the presence of high velocity deionised water. The lack of dissolved minerals in such water prevents the formation of an insoluble protective film. In most solutions, lead and lead alloys are resistant to galvanic corrosion because of the formation of a nonconductive corrosion film. In contact with more noble metals, however, lead can undergo galvanic attack which is accelerated by stray electrical currents. 

Coalescence The coalescence of droplets can occur whenever two or more droplets collide and remain in contact long enough for the continuous-phase film to become so thin that a hole develops and allows the liquid to become one body. A clean system with a high interfacial tension will generally coalesce quite rapidly. Particulates and polymeric films tend to accumulate at droplet surfaces and reduce the rate of coalescence. This can lead to the ouildup of a rag layer at the liquid-hquid interface in an extractor. Rapid drop breakup and rapid coalescence can significantly enhance the rate of mass transfer between phases. 

Particulate Scrubbers Wet collec tors, or scrubbers, form a class of devices in which a liquid (usually water) is used to assist or accomplish the collection of dusts or mists. Such devices have been in use for well over 100 years, and innumerable designs have been or are offered commercially or constructed by users. Wet-film collectors logically... 

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