Electrodeposition apparatus

Figure 26-2, p. 300, shows the Eberback electrolytic analyzer that will be used for this experiment. The Eberbach Corporation, Box 1024, Ann Arbor, MI 48106-1024, has a complete stock of electrodeposition apparatus, electrodes, chemicals and glassware. 

The selection of a particular deposition process depends on the material to be deposited and its availability rate of deposition limitations imposed by the substrate, eg, maximum deposition temperature adhesion of deposit to substrate throwing power apparatus required cost and ecological considerations. Criteria for CVD, electrodeposition, and thermal spraying are given in Table 2 (13). 

Only three of the metals, rhodium, palladium and platinum, need be considered. Of these only rhodium plating is of significant commercial importance, but the relatively low cost of palladium has made it attractive for contacts and printed circuits. Electrodeposited platinum is harder than the annealed bulk metal and finds applications in jewellery, the plating of scientific instruments, standard weights and parts of electrical apparatus. 

Electrodeposition experiments were carried out in the apparatus described earlier (4). The equipment is illustrated schematically in Figure 2. The circuit also included a strip chart recorder and integrator. A variety of metals were coated at the cathode using the standard condition of 200 V for 2 min. The cathode area was held constant at 7.3 cm, unless otherwise specified. After deposition, the metal test pieces were rinsed with deionized water, dried and weighed to determine the amount of polymer deposited. The number of coulombs was measured simultaneously in order to calculate current efficiencies. Results were analyzed and compiled in a simple computer program. A typical printout is shown below for a system with poor current cutoff (Table V ), and good cutoff (Table VI). The set of metals used as substrate are listed below. 

As shown in Eigure 22-6, the apparatus for an analytical electrodeposition without cathode potential control consists of a suitable cell and a 6- to 12-V direct-current... 

Figure 22-6 Apparatus for electrodeposition of metals without cathode-potential control. Note that this is a two-electrode cell.

The earlier work, before the invention of the electron microscope, was done with homemade apparatus called electron diffraction cameras. Many important studies were made of the structures of metal foils, electrodeposits, films deposited by evaporation, oxide films on metals, and surface layers due to polishing. 

Figure 2.90 Protocol for Pt electrodeposition on chemically H-terminated n-Si(lll) for model experiments on surface chemistry using the SoLiAS at undulator U49/2 at Bessy ii, recorded in the in-system apparatus shown in Figure 2.27. Three conditions have been analyzed by SRPES deposition under depletion (peak C ), and accumulation (C2)...

The residue from the vaporation is neutralized -with 8 N potassium hydroxide using phenolphthalein as indicator. When the solution is neutral, 2 ml of sodivim hypochlorite and 5 ml of 2 N potassium hydroxide are added to the tube, and the contents of the tube transferred to an electrodeposition cell with distilled water. (The final concentration of the alkali is. 1 N.) The Pu is electrodeposited on 1/2 in. polished stainless steel disks at 200 mA for 5 hr. The apparatus and techniques for the electrodeposition of Pu are described by Schwendiman et al. 

Caldwell CW, Parker RC, Diehl H (1944) Apparatus for automatic control of electrodeposition with graded electrode potential. Ind Eng Chem 16 532-535... 

Cyclic voltammograms and chronopotentiograms were obtained by means of a potentiostat/galvanostat PAR EG G model 273A interfaced to a 386 computer using the appropriate PAR software. These apparatuses also served for the DC and PC electrodepositions. 

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