Electrostatic wrap

A characteristic of electrostatic coating with both charging processes is that the charged powder will wrap around the back of the substrate, especially as the powder builds up on the front of the part being coated. This is usually referred to as electrostatic wrap. This can be both an advantage or a disadvantage. 

Electrostatic spraying is used in shops to coat conductive objects. It is very useful for odd-shaped objects such as wire fence, cables, and piping. An electrostatic potential of 60,000 volts on the object attracts oppositely-charged paint particles the spray can wrap around and coat the side of the object opposite to the spray gun. This technique produces very uniform finishes and has the least paint loss of the three methods. However, it is slow, requires expensive equipment, produces only thin coats, and is sensitive to wind currents. 

Electrostatic method This is also a w et method like the conventional process, except that the paint is now electrostatically charged, similar to the powder ptiint in a dry method as discussed later. The paint, being highly charged electrostatically, is wrapped around the object automatically. 

FIGURE 1.7 Wrap around effect of electrostatic paint spraying. (From Wang, L.K. et al. Case Studies of Cleaner Production and Site Remediation, Training Manual DTT-5-4-95, United Nations Industrial Development Organization, Industrial Sectors and Environment Division, Vienna, Austria, April 1995.)... 

Fig. 5.6 Example of electrostatic hybridization of cetyltrimethylammonium bromide (CTAB) capped Pt nanocubes with PSS-wrapped CNTs. Reprinted with permission from [81] (2008), Wiley.

Acetylcholineesterase Bilayer lipid membranes were prepared by adding a solution of egg phosphatidylcholine and dipalmi-toyl phosphatidic acid dropwise into the surface of aqueous 0.1 M KC1/10 mM HEPES, near the Saran Wrap partition of a two compartment plexiglass cell. A portion of AChE solution in 10 mM Tris hydrochloride buffer solution of pH 7.4 was applied. The electrolyte level was momentarily dropped below the orifice and raised to form a membrane. The membranes were used as transducers for the reaction of AChE with ACh. An external voltage (25 mV) was applied across the membrane between two Ag/AgCl reference electrodes. Enzymatically generated hydronium ion causes transient current due to alteration of the electrostatic field by the ionization of dipalmitoyl phosphatidic acid. The response delay time was directly related to the substrate concentration where acetylcholine can be determined from 1 pM upto mM level. [113]... 

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