Aluminum surfaces, effect

Adhesives. High concentration (>10%) solutions of poly(ethylene oxide) exhibit wet tack properties that are used in several adhesive appHcations. The tackiness disappears when the polymer dries and this property can be successfully utilized in appHcations that require adhesion only in moist conditions. PEO is also known to form solution complexes with several phenoHc and phenoxy resins. Solution blends of PEO and phenoxy resins are known to exhibit synergistic effects, leading to high adhesion strength on aluminum surfaces. Adhesive formulations are available from the manufacturers. 

Molybdenum disulfide is dispersed in greases and oils for lubrication in volatile carriers it is used to form dry coatings of lubricant. Sodium molybdate is an especially effective corrosion inhibitor on aluminum surfaces and is dissolved in cooling solutions to protect aluminum motor blocks in automobiles. 

The usual approach to good bonding practice is to prepare the aluminum surface as thoroughly as possible, then wet it with the adhesive as soon afterward as practical. In any event, aluminum parts should ordinarily be bonded within 48 h after surface preparation. However, in certain applications this may not be practical, and primers are used to protect the surface between the time of treatment and the time of bonding. Primers are also applied as a low-viscosity solution which wets a metal surface more effectively than more viscous, higher-solids-content adhesives. Corrosion-resistant epoxy primers are often used to protect the etched surface during assembly operations. Primers for epoxy adhesive systems are described in Chap. 10. 

The fin surface area will not be as effective as the bare tube surface, as the heat has to be conducted along the fin. This is allowed for in design by the use of a fin effectiveness, or fin efficiency, factor. The basic equations describing heat transfer from a fin are described in Kern (1950). The fin effectiveness is a function of the fin dimensions and the thermal conductivity of the fin material. Fins are therefore usually made from metals with a high thermal conductivity for copper and aluminum, the effectiveness will typically be between 0.9 and 0.95. 

Effects of Acid Rain on Indoor Zinc and Aluminum Surfaces... 

The intent of this paper is to present a methodology for estimating, from available information on concentrations and deposition velocities, the potential effects of anthropogenically derived acidic substances on indoor surfaces. Surface accumulation rates are derived that are applicable to all types of indoor surfaces. The discussion of the possible effects of the accumulated substances will concentrate on zinc and aluminum surfaces because data exists on the behavior of these metals in indoor environments (0. Aluminum forms a passivating oxide which protects against corrosion in most environments, while zinc is expected to corrode at a roughly linear rate over its lifetime. 

Estimating the deposition velocities of gaseous species is considerably more complex than estimating those for substances in particles, in part due to the uncertainties in the sticking and reaction probabilities. Such estimates have not been made but the potential effects of some of the typical gases can be surmised from available data on surface accumulation rates, e.g. sulfate accumulation on indoor zinc and aluminum surfaces is predominantly a result of particulate sulfate deposition rather than a corrosion reaction involving sulfur dioxide (0. 

Davis JA, Gloor R (1981) Adsorption of dissolved organics in lake water by aluminum oxide. Effect of molecular weight. Environ Sci Technol 15 1223-1229 Davis JA, Kent DB (1990) Surface complexation modeling in aqueous geochemistry. Rev Mineral 23 177-260... 

Surface Science of Ammonia Synthesis Structure Sensitivity of Ammonia Synthesis Kinetics of Dissociative Nitrogen Adsorption Effects of Aluminum Oxide in Restructuring Iron Single-Crystal Surfaces for Ammonia Synthesis Characterization of the Restructured Surfaces Effect of Potassium on the Dissociative Chemisorption of Nitrogen on Iron Single-Crystal Surfaces in UHV... 

Effect of Liquid-Crystalline Structures on Lubrication of Aluminum Surfaces... 

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