Watts electrolyte

Comparative studies in an electrochemical environment and under UHV conditions gain detailed information on die mechanistic role on anions and solvent molecules. This is demonstrated for nucleation and growth of thin epitaxial Ni films on Au(l 11). In contrast to Cu, no UPD or anion effects were found for Ni on Au [25]. In addition, due to the negative deposition potential of Ni the Au(l 11) electrode can be kept in a potential regime in vdiich Ihe surface exhibits the herringbone reconstruction, well known fiom UHV studies [26]. In Fig. 4(a), recorded in a modified Watts electrolyte [25], the zigzag pattern of die herringbone reconstruction is clearly visible on the electrode surface. 

Bright nickel deposits are obtained from one of the above electrolytes with additives. Because of its low costs, the Watts electrolyte is the most often used base... 

Salt was first electrochemicaHy decomposed by Cmickshank ia 1800, and ia 1808 Davy confirmed chlorine to be an element. In the 1830s Michael Faraday, Davy s laboratory assistant, produced definitive work on both the electrolytic generation of chlorine and its ease of Hquefaction. And ia 1851 Watt obtained the first Fnglish patent for an electrolytic chlorine production cell (11). 

Diaphragm cell for the electrolytic generation of CI2 invented by C. Watt (London) but lack of electric... 

The composition of the codeposition bath is defined not only by the concentration and type of electrolyte used for depositing the matrix metal, but also by the particle loading in suspension, the pH, the temperature, and the additives used. A variety of electrolytes have been used for the electrocodeposition process including simple metal sulfate or acidic metal sulfate baths to form a metal matrix of copper, iron, nickel, cobalt, or chromium, or their alloys. Deposition of a nickel matrix has also been conducted using a Watts bath which consists of nickel sulfate, nickel chloride and boric acid, and electrolyte baths based on nickel fluoborate or nickel sulfamate. Although many of the bath chemistries used provide high current efficiency, the effect of hydrogen evolution on electrocodeposition is not discussed in the literature. 

A typical cell generates a voltage of around 0.7 to 0.8 volts per cell and power outputs of a few tens or hundreds of watts. In order to achieve a significant output, cells have to be assembled in modules or stacks and electrically connected in series or in parallel. Different types of cells exist, according to the electrolyte used, and each type has a characteristic operating temperature (OT) ... 

In addition to these smaller applications, fuel cells can be used in portable generators, such as those used to provide electricity for portable equipment. Thousands of portable fuel cell systems have been developed and operated worldwide, ranging from 1 watt to 1.5 kilowatts in power. The two primary technologies for portable applications are polymer electrolyte membrane (PEM) and direct methanol fuel cell (DMFC) designs. 

Baillie, C.A., Castle, J.E., Watts, J.F. and Bader, M.G. (1991). Chemical aspects of interface adhesion between electrolytically oxidised carbon fibers and epoxy resins. In Proc. ICCMI8, Composites Design, Manufacture and Application. (S.W. Tsai and G.S. Springer, eds.), SAMPE Pub. Paper HE. 

They could serve as reserve batteries to be used with an electrolyte of sea water. Despic (1981) utilized the properties of A1 alloys with tin to shift the potential of A1 in the negative direction and increase the potential of the cell formed with Oz. The CF ion in sea water breaks down protective layers that would reduce the rate of anodic dissolution in an Al-02 battery. In fact, in sea water, such batteries can function at the extraordinarily high rate of 1 A cm4. The watt hours per kilogram at low rates of discharge are 500, which is well above the practical range for other batteries. In view of the commercialization of mechanically rechargeable Zn-air batteries for automotive applications, the commercialization of A1 batteries in the United States is conspicuous for its slowness.38... 

Electrodes B consist of fine platinum wires supported upon glass rods, and are to be used with a lamp of about 15 watts. They are to be used in testing the conductivity of solutions of weak electrolytes in a 3-inch vial. This vial may be raised until the electrodes are immersed in the liquid. Before testing the conductivity of any given solution rinse the platinum electrodes with... 

Watts bath — The Watts bath is the classical electrolyte for the -> electrodeposition of functional nickel coatings. It contains nickel sulfate (240-450 gL-1 of the hexahy-drate), nickel chloride (45-90 gL-1 of the hexahydrate), and boric acid (30-50 g L-1) and is usually operated between pH 2 and 4.5 and at 40-70 °C. The chloride content of the bath is crucial to ensure the dissolution of the nickel anode. In combination with - leveling agents and brighteners the Watts bath is also used for decorative nickel coatings. Its applicability for -> electroforming is limited due to tensile stresses in the deposits. 

In 1851, C. Watts patented a process for preparing chlorine, soda, hypochlorites, and chlorates by the electrolysis of soln. of alkali chlorides but little progress was made for many years. In 1882, A. P. Lidoff and W. Ticbomiroff described the preparation of hypochlorites by this process, and in 1883, E. Hermite patented a process, for the preparation of electrolytic bleaching liquor, which has been used in several countries, but is now regarded as an obsolete process. 

Fig. 1-36. Reflux-ratio timer. Ri, 3-megohm potentiometer R , 250,000-ohm J-watt Ra, 1-megohm potentiometer Rt, 50,000-ohm -watt Ci, 4-mfd. paper, 400 volts Cl, 2-mfd. paper, 400 volts Ct, C<, 8-mfd. electrolytic, 250 volts Vt, Fa, 117L7/M7GT Ry 1, Ry 2, double-pole double-throw relays, 1,000— 4,000-ohm coil Pi, Pa, 115-volt pilot lights X, standard receptacle (output) Si, Sa, single-pole single-throw switches. (Courtesy of Dr. H. Fischer and Analytical Chemistry.)...

Most modern nickel electrolytes are based on the composition proposed by Watts [26], which contains boric acid besides nickel chloride and sulfate. The chloride facilitates the dissolution of the anodes, but also increases the internal tensile stresses of the deposit. Boric acid serves as a buffering agent. The throwing power can be improved by adding inorganic salts. Recently, it... 

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. 

In Chapter 5 we turn to transport properties. R. Fernandez-Prini compares and rationalises the recent theoretical advances concerning the conductance of dilute electrolyte solutions and its dependence on concentration and solvent properties. M. Spiro discusses transference number determinations in a second section, and finally reviews the information available on limiting ionic mobilities in the various solvents. The final two chapters are devoted to kinetics. Firstly in Chapter 6 D. W. Watts discusses reaction kinetics and mechanisms, predominantly... 

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