Influence of the Structures of Hydrogen-Bonded Dimeric Molecules on Their Adsorption at Graphitized Thermal Carbon

E. S. Kuznetsova, A. V. Ul’yanov, and A. K. Buryak

Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences,
Leninskii pr. 31, Moscow, 119991 Russia

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Received June 5, 2008

Abstract — This study is devoted to the influence of the structures of hydrogen-bonded dimeric molecules on their adsorption at graphitized thermal carbon (GTC). The thermodynamic adsorption characteristics (TACs) of amino acid dimers and dimers of amino acids with acetic acid and formamide at GTC were determined. The results obtained for the adsorption of dimeric molecules at the carbon sorbent were compared with the calculated data for the molecules of the corresponding amino acids at GTC. The geometric parameters of dimeric molecules were varied to analyze the influence of the hydrogen bond lengths on the TACs of the compounds under study.

PACS: 68.43.-h

To the Mutual Effect of Surfaces of Nanometallic Systems and Reagents in Chemisorption Layers

N. P. Socolova and A. Yu. Tsivadze

Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninskii pr. 31, Moscow, 119991 Russia

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Received August 8, 2008

Abstract — Transformations of the carbon-monoxide adsorption layers on metallic nanosystems including group VIII metals are studied with the use of Fourier-transform infra-red (FTIR) spectroscopy. Depending on the experimental conditions, not only the state of the chemisorption layers, but also the surface structure of the systems changes.

PACS: 68.43.-h, 81.65. Rv

Numerical Simulation of Structure Transformation Processes as the Basis for Regulating the Properties of Nanodisperse Composition Systems and Materials

I. V. Kuchin and N. B. Uriev

Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences,
Leninskii pr. 31, Moscow, 119991 Russia

Received December 26, 2007

Abstract — Using computer simulations, the regularities of structure formation in disperse systems under dynamic conditions that predetermine the nature of the structure formed and, hence, the properties of obtained nanodisperse composition materials (materials with a nanodisperse component) are considered. Phenomena of the appearance and the development of a macroscopic structural heterogeneity, namely, the break in continuity of the structure in highly concentrated systems are reproduced, as are the conditions for the removing the break using surface active substances and vibrational impacts, which allows one to control the properties of disperse materials synthesized based on highly disperse solid phases.

PACS: 47.57.qk, 81.07.Wx

Study of the Sorption-Kinetic Properties of Carbon Molecular Sieves

A. V. Berveno^a,b and V. P. Berveno^b

^a Kemerovo State University, ul. Krasnaya 6, Kemerovo, 650043 Russia

^b Institute of Solid-State Chemistry and Mechanochemistry (Kemerovo Branch), Siberian Division,
Russian Academy of Sciences, Kemerovo, Russia

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Received December 10, 2008

Abstract — To elucidate the role of the electron-exchange properties of arene molecules that form the pore walls of carbon molecular sieves in their interactions with sorbate molecules, the correlation between the electron-exchange and sorption-kinetic properties was studied. The electron-exchange properties were estimated by using quantum-chemical modeling based on the energies of formation of singly charged anions and cations and neutral (both oxidized and reduced) molecules.

PACS: 68.43.-h

Heat-Resistant Glass-Ceramic Coatings Protecting Low-Alloyed  Steels against High-Temperature Gas Corrosion

K. Yu. Frolenkov

Orel State Technical University, Naugorskoe sh. 29, Orel, 302020 Russia

E-mail: laraostu.ru

Received December 13, 2007

Abstract — Glass-ceramic coating aimed at protecting low-alloyed and low-carbon steels under technological heating is developed; it decreases the metal losses to scale by a factor of 12, as well as substantially decreases the decarbonizing and dealloying of the metal surface. The coating is characterized by an optimum ratio of the refractory to glasslike phases, which provides a reliable adhesion of the coating to the metal. As a result of sintering solid and liquid phases, a barrier layer forms that prevents the oxygen penetration to the metal and, hence, decelerates the corrosion processes at the coating–metal interface under heating conditions.

PACS: 81.65.Kn

New Copolymer Products from Cyclic Carbonates and Isocyanate-Containing Compounds

I. L. Beilin and V. P. Arkhireev

Kazan State Technological University, ul. Karl Marx 68, Kazan, 420015 Tatarstan, Russia

Kazan State Institute of Finances and Economy
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Received December 11, 2008

Abstract — The anionic copolymerization of cyclic carbonates with aromatic and aliphatic diisocyanates is studied. The macro- and supramolecular structures of the resulting copolymer are determined. It is demonstrated that the strength and elasticity of the copolymer can be varied for various purposes.

PACS numbers: 81.05.Lq; 36.20.Fz

Electroplating Tin from Acidic Sulfate Baths Containing Benzaldehyde

A. Survila, Z. Mockus, S. Kanapeckait, M. Samuleviien, and V. Jasulaiten

Institute of Chemistry, Goshtauto 9, Vilnius, LT01108 Lithuania

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Received February 19, 2008

Abstract — Voltammetry and electrochemical impedance spectroscopy (EIS) are used in studying the kinetics of electroplating tin from 0.01 M Sn(II) baths containing 1 M H₂SO₄ and millimolar benzaldehyde (BA) additives. BA substantially decreases the reduction rate of Sn(II) in a broad range of cathodic polarization. Experimental EIS data are analyzed in terms of an equivalent R(Q_dl[R_aC_aW_a][R_ctQ_d]) circuit, including a Faraday process impedance ([R_ctQ_d] subcircuit), as well as diffusion and kinetic stages of BA adsorption ([R_aC_aW_a] subcircuit). Values of the subcircuit elements are found to depend on the duration of a contact between the electrode
and solution and on the BA concentration. An increase in the charge transfer resistance (R_ct) and a simultaneous decrease in the double layer capacitance (Q_dl) indicate that the electrochemical reduction of Sn(II) is inhibited by the BA adsorption. With an increase in the cathodic polarization, the effect becomes more pronounced, which is manifested in the low current densities and negative impedance values.

PACS: 81.15.Pq

The Corrosion Inhibition of Ti-alloy (VT9) in Mixture of H₂SO₄NaF by Organic Compounds¹

S. M. A. Hosseini, M. Mousavi, and M. Amiri

Department of Chemistry, Shahid Bahonar University of Kerman, Kerman 76169, Iran

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Received July 10, 2007

PACS: 82.45.Qr

Synergistic Inhibition between Schiffs Bases and Sulfate Ion on Corrosion of Aluminium in Sulfuric Acid¹

T. Sethi^a, A. Chaturvedi^a, R. K. Upadhyaya, and S. P. Mathur^b

^a Department of Chemistry, Government College, Ajmer, India

^b Department of Pure and Applied Chemistry, M.D.S. University, Ajmer, India

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Received April 15, 2008

Abstract — The effect of Schiff’s bases alone and Schiff’s bases with additive Na₂SO₄ on the corrosion of aluminium in H₂SO₄ have been investigated by using weight loss method. The present study revealed that aluminium in H₂SO₄ has been more efficiently inhibited by Schiff’s bases in the presence of additive Na₂SO₄ than Schiff’s bases alone due to the synergistic effect between Schiff’s bases and Na₂SO₄. Inhibition efficiency was found maximum upto 95.02% for aluminium in H₂SO₄ by Schiff’s bases in presence of additive Na₂SO₄. The adsorption of inhibitor accords with the Langmuir adsorption isotherm. Results obtained in both the cases indicate the dependence of inhibition efficiencies on the concentration of Schiff’s bases, additive Na₂SO₄ and also on the concentration of H₂SO₄ solution. The results show the increasing trends of inhibition efficiency with the concentration.

PACS: 82.45.Qr

Laser-Ellipsometric Monitoring of Corrosive Attack

V. A. Kotenev and A. Yu. Tsivadze

Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninskii pr. 31, Moscow,
119991 Russia

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Received October 10, 2008

Abstract — The problems under consideration are related to the development and practical application of laser, reflectometric, and ellipsometric methods of diagnostics of corrosion damage both at the micro and macro level. The following basic methods of probe laser and ellipsometric studies of corrosion electrochemical processes are considered: automatic and return-path ellipsometry, microscopic and video ellipsometric techniques, methods of light scattering, fluctuation and noise reflectometry, probe noise ellipsometry, microlocalized electrochemical processes, remote ellipsometry, laser and spectral tomography, and information optical 3D technologies for reconstructing the 3D structure of heterogeneous near-electrode layer. The primary attention was focused on the problems of application of laser and ellipsometric methods in the practice of real corrosion electrochemical studies.