18 Adhesion of Ice Frozen from Dilute Downloaded via TUFTS UNIV on July 11, 2018 at 00:37:19 (UTC). See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles.
Electrolyte Solutions H. H. G. JELLINEK Department of Chemistry, Clarkson College of Technology, Potsdam, Ν. Y. 13676
Introduction The adhesion of ice has long been studied but a satisfactory solution, from the practical standpoint of decreasing adhesion or increasing abhesion, has not yet been found. Complete abhesion can be achieved un der laboratory conditions but in practice any surface becomes rapidly contaminated after a few abhesions have taken place and the adhesion of ice continually i n creases with further abhesions. Experimental Data by Smith-Johannsen and Discussion Smith-Johannsen (1) studied the effect of impuri ties in water on the adhesion of ice by freezing such solutions to various substrates. He ascertained that small i n i t i a l concentrations (1 X 10 mole/liter(M) or less) of electrolytes (salts) decrease ice adhesion considerably. The adhesive strength was measured by the force per square centimeter needed to shear the ice off the substrate. The experiments were carried out at -10°C. The freezing point lowering of water by elec trolytes of such concentrations is only about 0.005°C. The ice was frozen rapidly enough so that the electro lyte remained homogeneously distributed throughout the frozen system, and did not have sufficient time to dif fuse away from the substrate/solution interface. Air bubbles appeared during the freezing process. Table I gives relevant data (S = salinity of i n i t i a l solution; p = salinity of grain boundary solution). The effectiveness of decreasing adhesion, or i n creasing abhesion, varies considerably with the partic ular electrolyte in solution. Thus 1 Χ 1 0 Μ Th(NO ) decreases adhesion by 97% on a wax-treated aluminum -3
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248 Mittal; Adsorption at Interfaces ACS Symposium Series; American Chemical Society: Washington, DC, 1975.
Mittal; Adsorption at Interfaces ACS Symposium Series; American Chemical Society: Washington, DC, 1975.
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2.91 3.08 1.95 4.00 1.93 2.99 1.17 1.40 1.15 0.88 1.54 1.20 1.27 2.17
10 2,45 2.20 0.85 0.65 0.76 2.78 0.39 1.38 1.30 0.11
