Anodic dissolution of zinc in aqueous-methanolic trichloroacetic acid solutions

1991 ◽  
Vol 56 (1) ◽  
pp. 236-240 ◽  
Author(s):  
Mohamed H. Hefny ◽  
Abdullah S. Babaqi ◽  
Mohamed S. El-Basiouny ◽  
Ragab M. Abdullah
Keyword(s):  
Anodic Dissolution ◽  
Water Molecules ◽  
Acid Solutions ◽  
Reaction Products ◽  
Temperature Analysis ◽  
Secondary Importance ◽  
Trichloracetic Acid ◽  
Dissolution Reaction ◽  
Steady State Current

Steady state current-potential curves for the anodic dissolution of zinc in aqueous-methanolic 0.25M trichloracetic acid solutions were constructed for wide ranges of the solution composition and temperature. Analysis of the results reveal that the increase of the water content and rise of temperature of the solution increases the corrosion rate. The most plausible role of the solvent lies within the stabilization of the anodic dissolution reaction products by water molecules. The changes in the properties of the solution due to the presence of methanol which give rise to hindrance of the anodic dissolution reaction are adsorption of methanol, change of viscosity and pH of the solution. These factors seem to be of secondary importance.

scholarly journals Anodic Dissolution of Spheroidal Graphite Cast Iron with Different Pearlite Areas in Sulfuric Acid Solutions

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
Yoshikazu Miyata ◽  
Yuki Kuwahara ◽  
Shukuji Asakura ◽  
Tadashi Shinohara ◽  
Takao Yakou ◽  
...  
Keyword(s):  
Cast Iron ◽  
Anodic Dissolution ◽  
Spheroidal Graphite ◽  
Anodic Current Density ◽  
Acid Solutions ◽  
Anodic Current ◽  
Dissolution Reaction ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron ◽  
Sulfuric Acid Solutions

The rate equation of anodic dissolution reaction of spheroidal graphite cast iron in sulfuric acid solutions at 298 K has been studied. The cast irons have different areas of pearlite. The anodic Tafel slope of 0.043 V decade−1and the reaction order with respect to the hydroxyl ion activity of 1 are obtained by the linear potential sweep technique. The anodic current density does not depend on the area of pearlite. There is no difference in the anodic dissolution reaction mechanisms between pure iron and spheroidal graphite cast iron. The anodic current density of the cast iron is higher than that of the pure iron.

Discussion: Role of the Anion in Passive Layer Formation

CORROSION ◽  
1969 ◽  
Vol 25 (3) ◽  
pp. 130-130 ◽  
Author(s):  
O. L. RIGGS
Keyword(s):  
Hydrochloric Acid ◽  
Optical Microscopy ◽  
Anodic Dissolution ◽  
Passive Layer ◽  
Acid Solutions ◽  
Layer Formation ◽  
Hydrochloric Acid Solutions

Abstract This brief note is a discussion of the paper “Optical Microscopy Studies of Anodic Dissolution of Iron in Sulfuric and Hydrochloric Acid Solutions” by L. Felloni and G. P. Cammarota, “Corrosion”, 24, 90 (1968) April.

Mechanistic variation in the reactions of substituted acetamides in aqueous sulfuric acid

1984 ◽  
Vol 62 (11) ◽  
pp. 2401-2414 ◽  
Author(s):  
Linda M. Druet ◽  
Keith Yates
Keyword(s):  
Sulfuric Acid ◽  
Water Molecules ◽  
Acid Solutions ◽  
Reaction Products ◽  
Aqueous Sulfuric Acid ◽  
Rate Determining Step ◽  
Wide Range ◽  
Acid Catalyzed ◽  
Catalyzed Reactions ◽  
Sulfuric Acid Solutions

The acid-catalyzed reactions of acetamide 1, N-tert-butylacetamide 2, and several p-substituted N-benzylacetamides (3 = H, 4 = CH3, 5 = OCH3, 6 = Cl, 7 = NO2) have been studied as a function of acidity and temperature over a wide range of aqueous sulfuric acid solutions (0–91%). Analysis of the reaction products and rate–acidity profiles revealed that four different mechanisms are operative over different acidity regions depending on the structure of the substrate. These are: two A-2 hydrolysis mechanisms with N-acyl fission of the substrate (with participation of one or several water molecules in the rate-determining step); A-1 hydrolysis with N-alkyl fission; and sulfonation, followed by hydrolysis. These conclusions are supported by three complementary and detailed kinetic treatments based on the hydration parameter, transition state activity coefficient, and excess acidity approaches. The acidity domains of each mechanism have been established for each substrate. The mechanistic conclusions are fully supported by the different values of ΔH‡ and ΔS‡ obtained in different regions of acidity.

scholarly journals Substrate wettability guided oriented self assembly of Janus particles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Meneka Banik ◽  
Shaili Sett ◽  
Chirodeep Bakli ◽  
Arup Kumar Raychaudhuri ◽  
Suman Chakraborty ◽  
...  
Keyword(s):  
Self Assembly ◽  
Janus Particles ◽  
Water Molecules ◽  
Functional Coatings ◽  
Hexagonal Close Packed ◽  
Local Densities ◽  
Inhomogeneous Properties ◽  
Metal Polymer ◽  
Specific Orientation

AbstractSelf-assembly of Janus particles with spatial inhomogeneous properties is of fundamental importance in diverse areas of sciences and has been extensively observed as a favorably functionalized fluidic interface or in a dilute solution. Interestingly, the unique and non-trivial role of surface wettability on oriented self-assembly of Janus particles has remained largely unexplored. Here, the exclusive role of substrate wettability in directing the orientation of amphiphilic metal-polymer Bifacial spherical Janus particles, obtained by topo-selective metal deposition on colloidal Polymestyere (PS) particles, is explored by drop casting a dilute dispersion of the Janus colloids. While all particles orient with their polymeric (hydrophobic) and metallic (hydrophilic) sides facing upwards on hydrophilic and hydrophobic substrates respectively, they exhibit random orientation on a neutral substrate. The substrate wettability guided orientation of the Janus particles is captured using molecular dynamic simulation, which highlights that the arrangement of water molecules and their local densities near the substrate guide the specific orientation. Finally, it is shown that by spin coating it becomes possible to create a hexagonal close-packed array of the Janus colloids with specific orientation on differential wettability substrates. The results reported here open up new possibilities of substrate-wettability driven functional coatings of Janus particles, which has hitherto remained unexplored.

A first-principles study of the atomic layer deposition of ZnO on carboxyl functionalized carbon nanotubes: the role of water molecules

2021 ◽  
Vol 23 (5) ◽  
pp. 3467-3478
Author(s):  
J. I. Paez-Ornelas ◽  
H. N. Fernández-Escamilla ◽  
H. A. Borbón-Nuñez ◽  
H. Tiznado ◽  
Noboru Takeuchi ◽  
...  
Keyword(s):  
First Principles ◽  
Ligand Exchange ◽  
Functional Group ◽  
Atomic Layer ◽  
High Reactivity ◽  
Water Molecules ◽  
Exchange Reactions ◽  
Layer Deposition ◽  
The Right

Atomic description of ALD in systems that combine large surface area and high reactivity is key for selecting the right functional group to enhance the ligand-exchange reactions.

scholarly journals The role of the water molecules in novel superconductor, Na0.35CoO2·1.3H2O

2004 ◽  
Vol 412-414 ◽  
pp. 182-186 ◽  
Author(s):  
H. Sakurai ◽  
K. Takada ◽  
F. Izumi ◽  
R.A. Dilanian ◽  
T. Sasaki ◽  
...  
Keyword(s):  
Water Molecules

The role of surface crystalline heterogeneities in the electrooxidation of carbon monoxide adsorbed on Rh(111) electrodes in sulphuric acid solutions

1997 ◽  
Vol 432 (1-2) ◽  
pp. 1-5 ◽  
Author(s):  
Roberto Gómez ◽  
JoséM. Orts ◽  
Juan M. Feliu ◽  
Jean Clavilier ◽  
Lorena H. Klein
Keyword(s):  
Carbon Monoxide ◽  
Sulphuric Acid ◽  
Acid Solutions

The dielectric β relaxation of polybenzoxazole: The role of water molecules

1977 ◽  
Vol 15 (6) ◽  
pp. 1121-1126 ◽  
Author(s):  
S. De Petris ◽  
V. Frosini ◽  
E. A. Nicol
Keyword(s):  
Water Molecules ◽  
Β Relaxation
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