The corrosion inhibition mechanism of Chlorophenicol and Hydralazine for the mild steel in 1M HCl was studied by chemical, electrochemical and adsorption measurement at 303-333 K temperature regions. The inhibition efficiency of the Chlorophenical and Hydralazine increases with increasing inhibitor but decreases with increase of temperature. The mechanism of the inhibition action attributed due to the adsorption of inhibitor on the surface of the metal, for which this adsorption process obeys Langmuir adsorption isotherm. The electrochemical Tafel analysis shows that the inhibitor acts as a mixed type, and gets adsorbed by either physically or chemically. Surface study was done by scanning electron microscopic method due to the formation of protective film on the metal surface.
Table of Contents
CHAPTER- 1 INTRODUCTION
1.1 Definition and importance of corrosion
1.2 Economic effects
1.2.1 Cost of corrosion
1.3 Types of corrosion
1.3.1 Dry corrosion
1.3.2 Wet corrosion
1.3.2.1 Uniform corrosion
1.3.2.2 Galvanic corrosion
1.3.2.3 Differential aeration corrosion
1.3.2.4 Crevice corrosion
1.3.2.5 Stress corrosion
1.3.2.6 Intergranular corrosion
1.3.2.7 Erosion corrosion
1.4 Electrochemical theory
1.5 Factors affecting the corrosion rate
1.5.1 Nature of the metal
1.5.1.1 Electrode potential of the metal
1.5.1.2 Purity of the metal
1.5.1.3 Hydrogen over voltage
1.5.1.4 Relative areas of anode and cathode
1.5.1.5 Nature of the corrosive product
1.5.2 Environment surrounding the metal
1.5.2.1 pH
1.5.1.2 Temperature of the corrosive environment
1.5.1.3 Humidity
1.6 Corrosion rate measurements
1.6.1 Weight loss measurements
1.6.2 Electrochemical measurements
1.6.2.1 Electrochemical Tafel polarization measurements
1.6.2.2 Electrochemical impedance Spectroscopy (EIS)
1.6.3 Adsorption isotherm
1.6.4 Theoretical study
1.6.4.1 Quantum chemical measurements
1.6.4.2 Quantum chemical parameters
1.6.4.3 Semi-empirical quantum measurements
1.7 Methods of corrosion control
1.7.1 Selection and Design of material
1.7.2 Protective Coatings
1.7.2.1 Metal coating
1.7.2.2 In-organic coating
1.7.2.3 Organic coating
1.7.3 Cathodic protection
1.7.3.1 Sacrificial anodic method
1.7.3.2 Impressed current method
1.7.4 Corrosion Inhibitors
1.7.4.1 Types of corrosion inhibitors
1.7.4.1.1 Adsorption corrosion inhibitors
1.7.4.1.2 Passivation corrosion inhibitors
1.7.4.1.3 Pickling corrosion inhibitors
1.7.4.1.4 Vapor-phase corrosion inhibitors
1.7.4.1.5 Slashing corrosion inhibitors
1.7.4.2 Toxic effect of inhibitors
1.7.4.3 Friendly corrosion inhibitors
1.7.4.4 Effect of the molecule structure on corrosion inhibition
1.8 Aim and scope of the present work
CHAPTER- 2 MATERIALS AND METHODS
2.1 Materials
2.1.1 Mild Steel
2.1.2 Pre-treatment of electrodes
2.1.3 Chemicals
2.1.3.1 Electrolytic medium
2.1.3.2 Inhibitor solution
2.1.4 Acute toxicity studies
2.2 Electrochemical cell and electrode assembly
2.2.1 Pretreatment of the electrochemical cell
2.3 Instrumental setup
2.4 Corrosion Studies
2.4.1 Chemical method
2.4.1.1 Weight loss measurements
2.4.2 Electrochemical measurements
2.4.2.1 Electrochemical Tafel polarization method
2.4.2.2 Electrochemical Impedance Spectroscopy (EIS)
2.4.3 Adsorption Isotherm
2.4.4 Activation Parameters
2.4.5 Theoretical method
2.4.5.1 Quantum chemical calculation
2.4.6 Surface study
2.4.6.1 Scanning electron microscopy (SEM)
CHAPTER- 3 Chloramphenicol drug as a corrosion inhibitor for mild steel in 1M HCl solution
3.1 Results and Discussions
3.1.1 Weight loss measurements
3.1.2 Electrochemical measurements
3.1.2.1 Tafel polarization measurements
3.1.2.2 Electrochemical impedance spectroscopy (EIS)
3.1.3 Adsorption isotherm and thermodynamic parameters
3.1.4 Activation parameters
3.1.5 Scanning electron microscopy (SEM)
3.3 Mechanism of inhibition
3.4 Conclusions
CHAPTER- 4 Hydralazine drug as a corrosion inhibitor for mild Steel in acidic medium
4.1 Results and Discussions
4.1.1 Weight loss measurements
4.1.2 Electrochemical measurements
4.1.2.1 Tafel polarization measurements
4.1.2.2 Electrochemical Impedance Spectroscopy (EIS)
4.1.3 Adsorption isotherm and thermodynamic parameters
4.1.4 Activation parameters
4.1.5 Quantum chemical studies
4.1.6 Scanning electron microscopy (SEM) analysis
4.3 Conclusions
CHAPTER- 5
Summary and main conclusions
References
Research Goals and Themes
The primary research objective of this work is to investigate the corrosion inhibition potential of specific pharmaceutical compounds, namely Chloramphenicol and Hydralazine, on mild steel in a 1M hydrochloric acid environment. The research seeks to identify effective, non-toxic, and eco-friendly alternatives to traditional, often hazardous, corrosion inhibitors by examining their adsorption characteristics, electrochemical performance, and influence on metal surface morphology.
- Electrochemical analysis of mild steel corrosion inhibition in acidic media using pharmaceutical-based organic inhibitors.
- Evaluation of the relationship between inhibitor molecular structure and corrosion inhibition efficiency.
- Thermodynamic and kinetic study of the adsorption process of inhibitors on metal surfaces.
- Characterization of surface morphology changes using Scanning Electron Microscopy (SEM).
- Correlation of experimental findings with theoretical quantum chemical calculations to elucidate inhibition mechanisms.
Excerpt from the Book
1.1 Definition and Importance of Corrosion
Metals and their alloys are widely used in structural and industrial applications rather than plastics, ceramics, wood, rubber etc., due to its excellent physical, chemical and thermal properties. These metals and their alloys undergo corrosion because of their exposure to corrosive environment. In this process, there is a transition of metals from their primary state to oxide state. The oxide form of the metals has lower energy and is thermodynamically stable. Metals are extracted from their stable oxidized state through metallurgical processes. Hence, metals are in unstable state due to higher energy. However, metals exhibit a natural tendency to retain their steady state either by chemical or electrochemical reactions to form a corrosive product on the metal surface. This process is referred to as corrosion.
“Corrosion is a chemical process of gradual degradation or deterioration of metals and their alloys through chemical or electrochemical reaction with their environment.”
Eg. Rusting of iron, green deposit on copper, etc.
Corrosion is a serious problem and it is a challenge to scientists to protect the metals from the attack of corrosion. To understand the corrosion process, it requires an electrochemistry background. Corrosion scientists study the mechanism and kinetics of corrosion for identifying its reasons in various applications. Thus, to decide the most convenient method to prevent or minimize the metal damage caused by corrosion attack.
Summary of Chapters
CHAPTER- 1 INTRODUCTION: This chapter provides a comprehensive overview of corrosion, including its definitions, types, electrochemical theories, and existing methods for corrosion measurement and control.
CHAPTER- 2 MATERIALS AND METHODS: This chapter details the experimental procedures, including material preparation, electrode cleaning protocols, chemical sourcing, and the instrumental setup used for weight loss and electrochemical studies.
CHAPTER- 3 Chloramphenicol drug as a corrosion inhibitor for mild steel in 1M HCl solution: This chapter investigates the efficiency of Chloramphenicol as a corrosion inhibitor for mild steel in 1M HCl, using weight loss, electrochemical measurements, and thermodynamic analysis.
CHAPTER- 4 Hydralazine drug as a corrosion inhibitor for mild steel in acidic medium: This chapter examines the anticorrosion potential of Hydralazine for mild steel in acidic environments, focusing on its mechanism, adsorption characteristics, and quantum chemical properties.
CHAPTER- 5: This final chapter synthesizes the research findings, offering a summary of the effectiveness of the studied inhibitors and presenting the main conclusions regarding their role in future corrosion protection strategies.
Keywords
Corrosion inhibition, Mild steel, 1M HCl, Chloramphenicol, Hydralazine, Adsorption isotherm, Tafel polarization, Electrochemical Impedance Spectroscopy, Quantum chemical calculations, Surface morphology, SEM, Thermodynamics, Activation energy, Eco-friendly inhibitors, Chemisorption.
Frequently Asked Questions
What is the fundamental focus of this research?
The research is primarily focused on identifying and evaluating non-toxic, eco-friendly pharmaceutical compounds that can act as effective corrosion inhibitors for mild steel in acidic industrial environments.
What are the key thematic areas of this work?
The work spans several key areas, including electrochemical corrosion measurement, adsorption thermodynamics, surface science (SEM), and quantum chemical modeling of inhibitor molecules.
What is the primary goal of the study?
The primary goal is to assess the efficiency of Chloramphenicol and Hydralazine as corrosion inhibitors, specifically looking to correlate their performance with molecular structure and provide insights into their adsorption mechanisms.
Which scientific methods are utilized for this analysis?
The study employs a multi-faceted methodology: weight loss analysis, potentiodynamic polarization (Tafel plots), Electrochemical Impedance Spectroscopy (EIS), and theoretical quantum chemical calculations (PM3 method).
What is covered in the main section of this publication?
The main sections provide detailed data on the inhibition efficiency, thermodynamic parameters (like enthalpy and entropy of adsorption), and surface analysis images obtained from testing the selected drugs under various temperatures and concentrations.
How would you characterize this work based on its keywords?
The work is characterized by terms related to material protection, electrochemistry, and pharmaceutical chemistry, specifically emphasizing environmental friendliness and detailed mechanistic understanding through experimental and theoretical validation.
How does the adsorption process of these inhibitors function according to the findings?
The research suggests that the inhibitors function through the adsorption of their molecules on the mild steel surface, effectively replacing water molecules and forming a protective passive layer, which is largely attributed to chemisorption processes.
What role do quantum chemical calculations play in this investigation?
Quantum chemical calculations are used to elucidate the electronic properties (such as HOMO/LUMO energies and dipole moments) of the inhibitors, which helps in predicting and confirming their active sites and reactivity with the metal surface.
What conclusions were reached regarding the temperature influence on inhibition?
Generally, it was observed that while inhibition efficiency is high at room temperature, it tends to change as temperature increases, with desorption processes often becoming more dominant at higher thermal ranges.
- Quote paper
- Dr. B M Prasanna (Author), 2016, Chloramphenicol and hydralazine as corrosion inhibitors for steel, Munich, GRIN Verlag, https://www.grin.com/document/377086
