In this work, Suregada multiflora leaves extract (SMLE) was studied as an environmentally friendly green corrosion inhibitor on iron metal in HCl solution by weight loss measurement. Metallic corrosion is one of the greatest problems in developed and developing countries due to unusual wastages of metallic instruments in the industrial sector. Metallic corrosion arises due to environmental effects. Corrosion is unfavourable as many direct and indirect costs arise due to the damages such as productivity losses, interruptions, breakdowns, environmental pollutions, and even some legal actions. The best method to reduce corrosion is the use of inhibitors.
A corrosion inhibitor represents the chemical compound that decreases the rate of corrosion of metallic substances when added to a gas or liquid phase. The inhibitors are mixed with solutions that are in direct contact with metal which prevents the anodic or cathodic reactions in an electrochemical cell that mitigates the corrosion. The plant extracts are biologically acceptable, eco-friendly, or green corrosion inhibitors which can respond in a proper way to mitigate the corrosion without damaging the eco-system of the environment. In the market, large numbers of inhibitors are available. Different organic and inorganic compounds are used for these purposes. But few of them are environmentally friendly.
Appropriate inhibitor selection is a very difficult task. Presently use of natural products like plant extracts is an emerging concept to make an eco-friendly planet. There are numerous studies where Plant-based corrosion inhibitors have been used. Recently green inhibitors attract the spotlight due to some of their advantages like they are eco-friendly, biodegradable, and nontoxic and does not contain any heavy metals. Plant extracts are found to be rich sources of phytochemicals which can be a good substitution for traditional toxic inhibitors. Leaves extract has been in the centre of interest of researchers due to its high content of phytochemicals compare to the other parts of the plants.
Table of Contents
1. INTRODUCTION
2. EXPERIMENTAL
2.1 Material Preparation
2.2 Preparation of Leaves Extract
2.3 Weight Loss Study
3. RESULTS AND DISCUSSION
3.1 Weight loss measurement
3.2 Adsorption isotherms
3.3 Thermodynamics parameters
3.4 The Activation energy (Ea)
4. CONCLUSION
5. REFERENCES
Research Objectives and Core Topics
This study aims to evaluate the effectiveness of an aqueous leaf extract from Suregada multiflora as an eco-friendly green corrosion inhibitor for mild steel submerged in a 1M HCl acidic environment. The research investigates the protective properties of the extract, the influence of concentration and temperature on corrosion rates, and the underlying adsorption mechanisms.
- Corrosion mitigation for mild steel in acidic solutions
- Application of plant-based green corrosion inhibitors
- Gravimetric weight loss analysis
- Adsorption isotherm modeling (Langmuir, Flory-Huggins, Langmuir-Freundlich)
- Thermodynamic analysis and activation energy calculations
Excerpt from the Publication
3.1.1 Exposure time and inhibition efficiency
Exposure or immersion time studies were performed to explore the stability of the corrosion inhibitor film as well as the rate of adsorption. The inhibition efficiency with various exposure times of iron in presence of a fixed concentration of inhibitors is presented in figure 1. The inhibition efficiency is determined from the weight loss measurement of mild steel in 1M HCl for 0.55g inhibitor concentration per 100 ml of corrosive medium and at 30°C temperature. It is clear from Figure-1 that the inhibition efficiency of Suregada multiflora on iron coupon raises with an increase in exposure time in the HCl medium. The main cause behind this is the formation of a very thin coating layer of inhibitor molecules on the metal surface.
There is a gradual rise in inhibition efficiency with rising immersion time and after 16 hours it decreases. The maximum corrosion inhibition efficiency was attained as a result of rapid adsorption of the inhibitor on the mild steel surface due to the presence of a greater number of active inhibitor molecules. The inhibition efficiency was found to be minimum (79.3%) after one hour of exposure period and it became maximum (96.28%) at 16 hours of exposure time.
Summary of Chapters
1. INTRODUCTION: Outlines the industrial challenge of metallic corrosion, the economic impact of degradation, and the shift towards eco-friendly, plant-based corrosion inhibitors.
2. EXPERIMENTAL: Describes the methodology for preparing the Suregada multiflora extract and the gravimetric procedures used to assess weight loss in mild steel coupons.
3. RESULTS AND DISCUSSION: Analyzes the experimental data, focusing on how exposure time, inhibitor concentration, and temperature influence inhibition efficiency, surface coverage, and corrosion rates, while validating the findings with adsorption isotherms and thermodynamic parameters.
4. CONCLUSION: Summarizes that the extract is an effective, eco-friendly, and cost-efficient inhibitor, with its mechanism primarily governed by the formation of a stable protective film on the metal surface.
5. REFERENCES: Lists the academic literature and previous studies supporting the experimental framework and interpretation of the results.
Keywords
Suregada multiflora, Green corrosion inhibitor, Mild steel, Acid corrosion, Gravimetric method, Weight loss, Inhibition efficiency, Adsorption isotherm, Langmuir isotherm, Thermodynamics, Activation energy, Physisorption, Surface coverage, Eco-friendly, HCl medium.
Frequently Asked Questions
What is the core focus of this research?
The research focuses on investigating the potential of Suregada multiflora leaves extract as a sustainable and non-toxic alternative to synthetic chemical inhibitors for preventing the corrosion of mild steel in hydrochloric acid.
What are the primary thematic fields covered?
The work spans materials science, green chemistry, and physical chemistry, focusing specifically on surface science, corrosion inhibition kinetics, and thermodynamics.
What is the main objective of the study?
The primary goal is to determine the optimal conditions under which the plant extract provides maximum protection to mild steel and to understand the mechanism by which the inhibitor molecules adsorb onto the metal surface.
Which scientific method was utilized?
The researchers employed the gravimetric method (weight loss measurement) to quantify the rate of corrosion and the efficiency of the inhibitor under various controlled temperatures and concentrations.
What is explored in the main body of the text?
The main body details the material preparation, the specific experimental setups for varying immersion times and inhibitor concentrations, and the subsequent mathematical modeling using various adsorption isotherms to characterize the inhibition process.
Which keywords define this publication?
Key terms include green corrosion inhibitor, Suregada multiflora, mild steel, weight loss, Langmuir isotherm, and inhibition efficiency.
How does exposure time affect the inhibitor's performance?
The study found that inhibition efficiency generally increases with exposure time due to the formation of a protective coating, reaching a peak efficiency of 96.28% at 16 hours before showing a slight decline.
Why are Langmuir isotherms used in this paper?
Langmuir isotherms were used to analyze the experimental data because they provided the best fit, confirming the formation of a protective monolayer of inhibitor molecules on the metal surface.
What does the thermodynamic analysis reveal about the adsorption process?
The analysis of free energy values indicates a mixed type of adsorption, suggesting that both physisorption and chemisorption mechanisms contribute to the inhibitor's effectiveness on the mild steel surface.
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- Abhik Chatterjee (Autor:in), Jiban Saha (Autor:in), Suvankar Debbarman (Autor:in), Dilliram Pokhrel (Autor:in), 2020, Suregada Multiflora Leaves Extract as a Green Corrosion Inhibitor, München, GRIN Verlag, https://www.grin.com/document/1184708
