Protecting Aluminum from Atmospheric Corrosion via Surface Hydrophobization with Stearic Acid and Trialkoxysilanes

The possibility of subjecting aluminum to hydrophobization and superhydrophobization (SHP) with ethanol solutions of trialkoxysilanes and stearic acid is explored. It is shown that SHP coatings are highly effective in protecting Al against atmospheric corrosion. The thicknesses of surface SHP layers are determined via X-ray photoelectron spectroscopy and ellipsometry. The protective ability of SHP coatings is determined by polarization measurements and corrosion tests in a salt fog chamber.     

Sol–Gel Synthesis of SiO<Subscript>2</Subscript> Containers Using Micelles of an Anionic Corrosion Inhibitor as a Template and the Prospects of Creation Protective Coatings Based on Them

It has been shown that silica container particles can be loaded with large amounts of an anionic corrosion inhibitor, sodium N-oleyl sarcosinate, at the stage of the sol?gel synthesis of the particles by using its micelles as a template. When incorporated into paint and varnish coatings, such containers efficiently protect low-carbon steel and D16 aluminum alloy from corrosion under severe conditions of neutral salt spray.     

Properties of metal-zinc oxide contacts

The known methods of forming surface barrier structures on zinc oxide are analyzed. The dependence of surface and contact properties of zinc oxide on thermal processing temperature in air and vacuum is studied. It is established that the contact may become rectifying or ohmic depending on the character of surface processing. It is shown that the major factor determining the properties of zinc-oxide contacts is the state of the semiconductor surface. The effect of moisture on the properties of such contact is studied.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 72–75, June, 1981.     

Short-lived <Superscript>224</Superscript>Ra and <Superscript>223</Superscript>Ra isotopes in the Anadyr River–Bering Sea system

The first results of activity measurement of short-lived radium isotopes dissolved in water in the Anadyr River–Bering Sea transit system are presented. The trends of the radionuclide behavior after passage through high-gradient river–coastal sea water mixing zone were identified and the exchange rate of the horizontal mixing was determined. The ²²⁴Ra/²²³Ra activity ratio was used to construct the “radium age” model, which served for estimating the residence time of brackish water in the Anadyr River estuary. The factors affecting this value were elucidated.     

An investigation of complexes of some model tripeptides containing phenylalanine and tyrosine residues with DNA by Fourier1H NMR spectroscopy

Complexes of native and denatured DNA with model tripeptides containing phenylalanine or tyrosine residues flanked by lysine or arginine residues, respectively have been investigated by pulsed Fourier¹H NMR spectroscopy. The existence of shifts into the strong-field region of the signals of aromatic protons of the model tripeptides in the complexes both with native and with denatured DNA has been shown. Results have been obtained that indicate the possibility of the intercalation of the side chains of aromatic amino acid residues into the DNA double helix.     

An investigation of complexes of some model tripeptides containing phenylalanine and tyrosine residues with DNA by Fourier1H NMR spectroscopy

Complexes of native and denatured DNA with model tripeptides containing phenylalanine or tyrosine residues flanked by lysine or arginine residues, respectively have been investigated by pulsed Fourier¹H NMR spectroscopy. The existence of shifts into the strong-field region of the signals of aromatic protons of the model tripeptides in the complexes both with native and with denatured DNA has been shown. Results have been obtained that indicate the possibility of the intercalation of the side chains of aromatic amino acid residues into the DNA double helix.All-Union Scientific-Research Institute of the Genetics and Breeding of Industrial Microorganisms, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 751–755, November–December, 1986.     

Formation of passivating layers by 1,2,4-triazole derivatives on copper in aqueous solutions

Ellipsometry and electrochemical measurements are used to study the adsorption of some substituted 1,2,4-triazoles on copper and their effect on dissolution of copper in aqueous buffer solutions at pH 7.4. It is found that the adsorption of triazole compounds on copper is polymolecular at potential Е = 0.0 V, in relation to a normal hydrogen electrode. The first layer is described by the Temkin equation with free adsorption energy (−ΔG_a⁰) = 55.2–76.3 kJ/mol and an energy heterogeneity factor that varies from 0.91 to 2.5. The maximum value of −ΔG_a⁰ is found for an acid and a hydrogen sulfide corrosion inhibitor that is a mixture of triazole derivatives. The same inhibitor is the one least sensitive to the energy heterogeneity of the surface of a copper electrode, due to its high chemical reactivity and ability to be adsorbed on different active sites. This inhibitor is likely chemisorbed on copper and forms an ultrathin coating in an aqueous solution that is vastly superior to similar coatings produced by the familiar corrosion inhibitors of triazole group compounds in protecting against atmospheric corrosion.