scholarly journals Influence of gelatin on corrosion behavior of copper in acid media

2012 ◽  
Vol 66 (2) ◽  
pp. 193-200
Author(s):  
Dragisa Todorovic ◽  
Dragan Milenkovic ◽  
Milutin Milosavljevic ◽  
Dragan Markovic
Keyword(s):  
Adsorption Isotherm ◽  
Corrosion Protection ◽  
Inhibitory Action ◽  
Corrosion Current ◽  
Copper Surface ◽  
Langmuir Adsorption Isotherm ◽  
Copper Corrosion ◽  
Citric Acid Solution ◽  
Acid Media ◽  
Langmuir Adsorption

This paper presents the results of gelatin and benzotriazole (BTA) inhibitory action on copper in the acid medium by the method of weight loss. The investigation was carried out in the citric acid solution (1, 5 and 20%) at the temperature of 293 K. Under such conditions, the gelatin showed higher efficiency of corrosion protection in comparison to BTA. The results, obtained through the Gibbs and Langmuir adsorption isotherm, show that gelatin adsorption on copper surface obey the Langmuir adsorption isotherm model, as well as that the adsorption is a spontaneous process. The polarization measurements show the potential of full passivation shift towards more negative values, and the increase of corrosion current in both cases but being more pronounced with the BTA. The results obtained in this paper indicate that the inhibition gelatin can be used as the BTA substitute for the copper corrosion protection.

scholarly journals Fatty Amidine as Copper Corrosion Inhibitor

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Zainal Alim Mas’ud ◽  
Noviyan Darmawan ◽  
Januari Dawolo ◽  
Yusuf Bramastya Apriliyanto
Keyword(s):  
Corrosion Inhibitor ◽  
Corrosion Inhibitors ◽  
Inhibition Efficiency ◽  
Adsorption Process ◽  
Copper Surface ◽  
Langmuir Adsorption Isotherm ◽  
Copper Corrosion ◽  
Langmuir Adsorption ◽  
New Type ◽  
Corrosion Inhibition Efficiency

The development of green and sustainable corrosion inhibitors for copper in a corrosive marine environment is highly desired. Herein, we studied the fatty acid-based amidine as the new type of renewable corrosion inhibitor. Stearamidine salt was used as a model inhibitor, and it was synthesized through stearonitrile intermediate with an excellent isolated yield of 88%. We used electrochemical (potentiodynamic polarization) and morphological (scanning electron microscopy) measurements to assess the corrosion inhibition efficiency of stearamidine in 3.0 wt.% NaCl at 300 K. We show that, in such a condition, the optimum inhibition efficiency of 96% was achieved using only 0.2 mM stearamidine. The results suggested the fatty amidine is a promising corrosion inhibitor for copper that is suitable in the saltwater ecosystem. The thermodynamic parameters of the interaction between the stearamidine and the copper surface were determined, and the result suggests that the adsorption process occurred accordingly with the Langmuir adsorption isotherm and involved both physisorption and chemisorption.

scholarly journals Diffusion of calcium ions in retinal rods. A theoretical calculation.

1981 ◽  
Vol 77 (4) ◽  
pp. 475-487 ◽  
Author(s):  
S McLaughlin ◽  
J Brown
Keyword(s):  
Diffusion Coefficient ◽  
Adsorption Isotherm ◽  
Calcium Ions ◽  
Outer Segment ◽  
Effective Diffusion ◽  
Langmuir Adsorption Isotherm ◽  
Diffuse Double Layer ◽  
Langmuir Adsorption ◽  
Retinal Rods ◽  
Disk Membrane

The Fick diffusion equation is combined with the Langmuir adsorption isotherm and the relevant equations from the Gouy-Chapman theory of the electrical diffuse double layer to demonstrate that the effective diffusion coefficient of calcium ions, both in the cytoplasm of the rod outer segment and within the aqueous space bounded by the disk membrane, should be reduced by a factor of 10-100 because these ions adsorb to phospholipids present in the disk membrane.

A further note on the measurement of the affinity of a dye (Azure A) for histological substrates

1965 ◽  
Vol s3-106 (76) ◽  
pp. 299-306
Author(s):  
D. J. GOLDSTEIN
Keyword(s):  
Adsorption Isotherm ◽  
Goblet Cell ◽  
Binding Sites ◽  
Langmuir Isotherm ◽  
Langmuir Adsorption Isotherm ◽  
Intestinal Epithelial ◽  
Langmuir Adsorption ◽  
Azure A ◽  
First Approximation ◽  
The Ideal

If two histological sections, of thickness nµ and 2nµ, and having the same apparent intensity of staining, are at equilibrium with dyebaths of concentration B1 and B2 respectively, the affinity of the histological substrate for the dye is, under denned conditions, given by the expression ΔF° = - RT In I/B, where B is either (i) B2 if the thinner section is stained to saturation, or (ii) B1 if B1 = 3B2. The affinity tends to be greater when measured in a weaker dyebath, as implied in method (ii). Evidence is presented suggesting that the uptake of the basic dye Azure A by pancreatic basal chromidial substance, goblet cell mucin and intestinal epithelial cytoplasm follows a Langmuir adsorption isotherm to a first approximation, in that, at low dyebath concentrations, the uptake of dye is proportional to the concentration of dyebath with which the substrate is in equilibrium, while in strong dyebaths the uptake approaches a plateau. A deviation from the ideal Langmuir isotherm in dyebaths of moderate concentration, observed in epithelial cytoplasm and to a lesser extent in pancreatic basal chromidial substance, may have been due to interaction between neighbouring dye-binding sites, or to the presence in a single area of sites with different affinities for the dye.

THE SORPTION OF ACIDS BY WOOL

1949 ◽  
Vol 27b (12) ◽  
pp. 879-889 ◽  
Author(s):  
R. Donovan ◽  
P. Larose
Keyword(s):  
Hydrochloric Acid ◽  
Adsorption Isotherm ◽  
Sulphuric Acid ◽  
Sodium Sulphate ◽  
Langmuir Adsorption Isotherm ◽  
Langmuir Equation ◽  
Recent Application ◽  
Satisfactory Explanation ◽  
Isotherm Equation ◽  
Langmuir Adsorption

The amount of acid sorbed by wool from solutions of sulphuric acid of four different strengths (namely, 0.0505, 0.0339, 0.0182, and 0.0101 molar) and containing sodium sulphate in amounts varying up to 0.16 molar has been determined. It has been found that the presence of the salt has little effect on the quantity of acid sorbed within those limits. The results are analyzed in the light of the theory of Gilbert and Rideal but this theory fails to give a satisfactory explanation of the results obtained. It is possible, however, to explain the results of the authors' experiments on the basis of the recent application of the Donnan equilibrium by Peters and Speakman. The Langmuir adsorption isotherm equation has been applied to data on the absorption of hydrochloric acid and of sulphuric acid by wool. The data appear to fit the Langmuir equation and give, for the maximum combining capacity, values that agree well with those estimated in other ways.

Adsorption Characteristic Research of Sediments of Lake Baiyangdian

2014 ◽  
Vol 511-512 ◽  
pp. 55-58
Author(s):  
Zhe Qin ◽  
Qian Wang ◽  
Zheng Liu
Keyword(s):  
Adsorption Isotherm ◽  
Nitrogen Adsorption ◽  
Ammonia Nitrogen ◽  
Langmuir Adsorption Isotherm ◽  
Adsorption Characteristic ◽  
Langmuir Adsorption ◽  
Lake Baiyangdian ◽  
Object Of Study ◽  
Total Maximum ◽  
Adsorption Quantity

This paper regarded the sediments of Lake Baiyangdian as the object of study, researched and analyzed ammonia nitrogen adsorption characteristics of sediment samples. The results showed that: the sediments adsorption to ammonia nitrogen reached a state of equilibrium after 2.5h, The ammonia nitrogen adsorption rate was maximum in 0~10min. Sediment adsorption of ammonia nitrogen was higher as ammonia nitrogen liquid balance concentration increased. The adsorption isotherm curve of ammonia nitreogen can be fitted well by the Langmuir adsorption isotherm model. The total maximum adsorption quantity of ammonia nitrogen by the sediments of Lake Baiyangdian is between 54.12mg/kg to 240.12mg/kg.

scholarly journals Corrosion prevention of commercial alloys by air-water interface grown, edge on oriented, ultrathin squaraine film

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Rajiv Kumar Pandey ◽  
Richa Mishra ◽  
Gopal Ji ◽  
Rajiv Prakash
Keyword(s):  
Corrosion Protection ◽  
Surface Characterization ◽  
Electrochemical Techniques ◽  
Copper Substrate ◽  
Chemical Properties ◽  
Copper Surface ◽  
Ultrathin Film ◽  
Water Interface ◽  
Acid Media ◽  
Air Water Interface

Abstract Copper is one of the most demanded commercial metal/alloys in world market. The demand for copper in industries such as electrical, electronics, automobile, telecommunications, defence, etc. as well as in daily life has escalated in the recent years due to its versatile physical and chemical properties. However destruction of copper surface by any means, preferably corrosion, can limit its vast application. For protection from corrosion, various techniques are used to coat metal substrates with passivating materials. These techniques are either complex as well as expensive, or provide incomplete protection in acid media. To address these issues, floating film transfer method (FFTM) is utilized in this work for obtaining ultrathin film of squaraine (passivating molecule) as well as their easy and fast transfer over copper substrate. The squaraine film is deposited on copper substrate in layers, viz., 1 to 4 layers. The corrosion behavior is examined in 0.1 M HCl using electrochemical techniques as well as surface characterization techniques, which portray that copper corrosion is hampered in harmony with the layers deposited. Nearly 40% corrosion protection is reached for copper coated with 1 layer of squaraine. However, the protection is amplified up to 98% with 4 layers of squaraine, which clearly substantiates the supremacy of this coating method over reported methods of protection. This technique and the material (squaraine) are both for the first time being used in the field of corrosion protection. The easy growth of ultrathin film at air-water interface as well as its rapid transfer over substrate promotes use of FFTM for efficient corrosion protection on industrial scale.

Hyperhydrophilic three-dimensional crosslinked beads as an effective drug carrier in acidic medium: adsorption isotherm and kinetics appraisal

2015 ◽  
Vol 39 (5) ◽  
pp. 3835-3844 ◽  
Author(s):  
Sachin Mane ◽  
Surendra Ponrathnam ◽  
Nayaku Chavan
Keyword(s):  
Adsorption Isotherm ◽  
Acidic Medium ◽  
Drug Carrier ◽  
Drug Loading ◽  
Three Dimensional ◽  
Langmuir Adsorption Isotherm ◽  
Effective Drug ◽  
Crosslinked Polymers ◽  
Langmuir Adsorption

Langmuir adsorption isotherm demonstrates monolayer drug loading with hyperhydrophilic three-dimensional crosslinked polymers. Furthermore, the pseudo order kinetics were also evaluated.

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