Electrochemical plating

The sensitivity enhancement achieved by VPD is determined by the ratio of the substrate area to the area of the detector aperture (analyzed area), provided there is fiill collection of the impurities. This has been demonstrated for Fe and Zn. For Cu and Au, however, only a small percentage can be collected using this technique, due to electrochemical plating. An example comparing direct TXRF with VPD-TXRF on the same substrate is shown in F%ure 4. 

In order to perform the electrodeposition, first a 3 nm layer of Au was sputter-coated onto one side of the ca. 50 p.m thick membrane to form a conductive surface. A Ni substrate layer was then electrochemically plated on top of the Au, as to... 

Reactor 33 [R 33] Electrochemical Plate-to-Plate Micro Flow Reactor... 

Reactor type Electrochemical plate-to-plate micro flow reactor Reactor volume 35 pi... 

To prepare metal hexacyanoferrate films, very frequently the following procedure was followed first a film of the respective metal, for example, cadmium [79], copper [80], silver [81], or nickel [82, 83] was electrochemically plated on the surface of a platinum electrode, and that was followed by chemical oxidation of the metal film in a solution of K3[Fe(CN)6], leading to the formation of the metal hexacyanoferrates. The same method has been used to produce films of nickel hexacyanoruthen-ate and hexacyanomanganate using the appropriate anions [83]. It is also possible to perform the oxidation of the deposited metals in solutions containing hexacyano-ferrate(II) by cyclic oxidation/reduction of the latter. In a similar way, films of copper heptacyanonitrosylferrate have been deposited [84]. 

Electrophoretic deposition is similar to electrochemical plating. But, instead of deposition from solution, particles are deposited from suspension. It is possible to produce thin and thick films of very consistent thickness, even on irregularly shaped substrates, with very short deposition times. Also, the equipment necessary to deposit the films has a relatively inexpensive power supply. However, the films are only physically bonded to the substrate and permanent chemical adhesion must be affected by firing, which can have deleterious results on the mechanical properties of metallic substrates. 

S.4.2.3 Nickel-phosphorus Excellent corrosion protection is observed if the nickel layer contains phosphorus. This was first observed with electroless NiP layers (see Sect. 5.5.4.2.4). During the last years, electrochemical plating processes for nickel phosphorus have been developed. In these processes, a phosphorus source has to be added to the electrolyte either sodium phosphite or sodium hypophosphite are used. The other components of the electrolyte are similar to a Watts bath (see Sect. 5.S.4.2). Table 6 lists a typical composition. 

The electrochemical plating method was used to fabricate IPMCs with different types of electrodes. The exact chemicals and reduction materials are shown in Table. 2.1. An Instron 5565 machine was used for the tensile testing (see Fig. 2.12 (a) for the setup). The fabricated IPMC samples were punched out using a dog-bone shaped punch mold. Its size followed ASTM 638 and 882, as shown in Fig. 2.12 (b). The tensile test was per-... 

Electrochemical Electrochemical plating with metals Redox behavior of DND... 

For the electrochemical plating of silver, a 99.9% silver anode is used with an electrolyte composed of [Ag(CN)2] and other required additives. Silver should not come into direct contact with steel or severe corrosion can occur. Steel parts can be protected by first coating with copper or nickel. Silver coating is commonly used for flatware, hol-loware, jewelry, electrical, and mechanical applications. Chemical methods are available to apply silver as a coating to plastic or glass. 

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