Zinc films

Various strategies are employed to prevent corrosion. The use of paint as a protective coating is described in our chapter introduction. A metal surface can also be protected by coating it with a thin film of a second metal. When the second metal is easier to oxidize than the first, the process is galvanization. Objects made of iron, including automobile bodies and steel girders, are dipped in molten zinc to provide sacrificial coatings. If a scratch penetrates the zinc film, the iron is still protected because zinc oxidizes preferentially ... 

Semiconductor films of ZnO used as operational elements are obtained by oxidation at - 500 - 600°C in the jet of purified oxygen of zinc film deposited at vacuum iP 10 Torr) on substrates made of fused quartz with subsequent sintering at - 350°C at high vacuum conditions [34]. As it was concluded in paper [17] the sintered polycrystalline sample obtained in such a manner should not be considered as a set of various separate crystallites touching each other but rather as a monolithic pattern in which microcrystals with diameter of 1-10 pm are linked with each other by bridges with length and thickness of the order of 0,1 pm (see Fig. 2.4). 

The most reliable and easy to control method of oxide films application is provided by either sputtering of an oxide layer (e. g., by a laser beiun), or evaporation of a thin metal zinc film (its resistance is usually 5-10 Ohm) from tantalum vessel onto a thoroughly prepared clean quartz substrate in a vacuum of Torr (containing no oil and... 

The same mechanism of zinc electrodeposition on the GC electrode was observed in sulfate, chloride, and acetate ion solutions [227]. The anions mainly affected the nucleation densities during zinc deposition, which resulted in a different surface morphology. The nucleation rate constant was the same in the chloride and sulfate solutions and was equal to 1.22 x 10 s h In the presence of acetate and chloride ions, the deposited zinc film tends to grow in a multilayered pattern, while in sulfate solution, the zinc deposition forms irregular grains. A new approach to the estimation of zinc electrocrystallization parameters on the GC electrode from acetate solutions was described by Yu et al. [228]. 

Dilution of the zinc with other pigments (extenders) requires careful compromise the protective qualities of a conductive zinc film with continuous contact should be retained without increasing the emission of toxic vapors. Diluent pigments are therefore chosen for their heat resistance and contribution to the impermeability of the films they include titanium dioxide, iron(III) oxide, talc, mica, and china clay. 

Kanematsu H, Masuo Y, Omura H, Oki T (2001) Rapid formation of tin-zinc film fiorn stacking layers by lasers irradiatitm. The second Asian conference on heat treatment of materials, pp 230-235... 

The life of rope made from galvanized steel wires is, however, greater than that of the individual wires (Schikorr, 1943-1944 ASTM, 1956). Schi-korr explains this by pointing out that the parts of the wire that lie on the outside are corroded more rapidly and, when the zinc film is penetrated in... 

The use of crystal motifs to synthesize zinc films from a relatively low concentration Zn(C104)2 6H20 electrolyte (0.01-0.3 M) with 0.1 M LiC104 3H20... 

Pereira MS, Barbosa LL, Souza CAC et al (2006) The influence of sorbitol on zinc film deposition, zinc dissolution process and morphology of deposits obtained from alkaline bath. J Appl Electrochem 36 727-732. doi 10.1007/sl0800-006-9133-z... 

Lopez CM, Choi K-S (2006) Electrochemical synthesis of dendritic zinc films composed of systematically varying motif crystals. Langmuir ACS J Surf Coll 22 10625-9. doi 10.1021/ la0611864... 

FIGURE 7.6 Strength, P, (a) and limiting deformation, (b) e, as a function of the temperature for the stretching of (1) polycrystalline samples of pure tin and (2) samples of tin covered with zinc film. Tin melting point,... 

Study of the influence of the polyalcohol sorbitol on the electrodeposition of copper-zinc films from a non-cyanide bath. /. Electroanal. Chem., 562 (2), 153-159. 

Sacrificial pigments usually contain zinc in the form of zinc dust in large amounts. When in electrical contact with the steel surface, the zinc film acts as the anode of a large corrosion cell and protects the steel cathode. In other words, zinc sacrificially corrodes instead of steel. In addition to sacrificially corroding, zinc dust also provides barrier action due to formation of its insoluble corrosion products. ... 

---