Corrosion Inhibition of Aluminium in Hydrochloric Acid by Natural Plant Extracts

Research Paper (postgraduate) , 2014 , 94 Pages , Grade: 3

Chemistry - General

Aluminium, being a highly reactive metal, corrodes rapidly in acidic (pH < 6) and alkaline (pH > 12.5) media. Hence it has to be protected when it is likely to come in contact with such solutions, e.g., during cleaning or acid pickling. One method of protection is the addition of inhibitor to the corroding medium. In the present work, ethanol extract of Azadirechta indica and Murraya koenigii leaves have been investigated as corrosion inhibitor for aluminium in aqueous hydrochloric acid.
The corrosion of Alluminium in plain hydrochloric acid, as well as inhibited, is found to increase with a rise in temperature. Thus in uninhibited 0.5 M HCl the loss in weight due to corrosion for an exposure period of 60 min increases from 736 mg/dm2 at 35oC to 852, 922, and 958 mg/dm2 at 45oC, 55oC and 65oC respectively.
In inhibited 0.5 M HCl containing 1.30% of Azadirechta indica, it was observed that at 35oC and for an exposure period of 60 min Azadirechta indica confer 100.0% protection. In A. indica, it is observed that the compound at 1.30% concentration show an efficiency 100.0% at 35°C. As the temperature is increased the efficiency decreases. In the case of A.indica, the efficiency decreases slightly and is found to be 72.96% at 65°C. It appears that in the case of Azadirechta indica, the adsorption is of physisorption type which decreases with a rise in temperature.
The surface morphology of the Al samples in the absence and presence of A.indica and M.koenigii leaves extract was investigated after weight loss using SEM technique. The badly damaged surface obtained when the metal was kept immersed in 0. 5 M HCl for 60 min without inhibitor indicates significant corrosion. However, in presence of inhibitor the surface has remarkably Improve with respect to its smoothness indicating considerable reduction of corrosion rate. This improvement in surface morphology is due to the formation of a good protective film of inhibitor on aluminium surface which is responsible for inhibition of corrosion. The order of efficiency at 1.30% v/v inhibitor concentration in 0.5 M hydrochloric acid was found to be : Azadirechta indica (100.0%) Murraya koenigii ( 94.79%)

Inhaltsverzeichnis

• Chapter-1. Introduction of corrosion
  • 1.1 General Aspect of Corrosion
  • 1.2 Factors Influencing Corrosion
  • 1.3 Types of Corrosion
  • 1.4 Aim of Research work
  • 1.5 References
• Chapter -2. Performance and Impact of plant extracts as Metallic Corrosion Inhibitors
  • 2.1 Plant extract as Corrosion Inhibitors
  • 2.2 Effect of Functional Group on Inhibitors
  • 2.3 Classification of Inhibitors
  • 2.4 Phenomenon of Adsorption
  • 2.5 Azadirechta indica utilized in the present work its properties And uses as corrosion inhibitor
  • 2.6 Murraya koenigii utilized in the present work its properties And uses as corrosion inhibitor
  • 2.7 References
• Chapter -3. Spectral studies on plants use as green inhibitor
  • 3.1 Infrared spectroscopy
  • 3.2 X-ray fiuoresence study
  • 3.3 References
• Chapter -4. Experimental Methods and Discussion of the Results
  • 4.1 Experimental Method
  • 4.2 Preparation of plant extract
  • 4.3 Discussion of the Results
  • 4.4 Effect of Inhibitor Concentration
  • 4.5 Effect of Exposure Period
  • 4.6 Effect of Temperature
  • 4.7 Scanning electron microscopic study
  • 4.8 References
• Chapter -5. Summary of the Dissertation
  • 5.1 Effect of Inhibitor Concentration
  • 5.2 Effect of Exposure Period
  • 5.3 Effect of Temperature
  • 5.4 Scanning electron microscopic study

Zielsetzung und Themenschwerpunkte

This research investigates the effectiveness of natural plant extracts, specifically from Azadirechta indica and Murraya koenigii leaves, as corrosion inhibitors for aluminium in hydrochloric acid. The study aims to determine the impact of inhibitor concentration, exposure time, and temperature on the corrosion inhibition process. The research also explores the mechanism of action of these plant extracts as corrosion inhibitors.

• Corrosion inhibition of aluminium in hydrochloric acid
• Effectiveness of natural plant extracts as corrosion inhibitors
• Impact of inhibitor concentration, exposure time, and temperature on corrosion inhibition
• Mechanism of action of plant extracts as corrosion inhibitors
• Potential applications of plant extracts in corrosion control

Zusammenfassung der Kapitel

Chapter 1 provides a comprehensive introduction to the phenomenon of corrosion, covering its general aspects, influencing factors, and various types. It also outlines the research objectives and the specific focus on utilizing plant extracts as corrosion inhibitors for aluminium in hydrochloric acid.

Chapter 2 delves into the performance and impact of plant extracts as metallic corrosion inhibitors. It discusses the use of plant extracts as corrosion inhibitors, the effect of functional groups on inhibitor efficacy, and the classification of inhibitors. The chapter also explores the phenomenon of adsorption and its role in corrosion inhibition. It then focuses on the specific properties and uses of Azadirechta indica and Murraya koenigii as corrosion inhibitors, highlighting their potential for this application.

Chapter 3 examines the spectral studies conducted on the plant extracts used as green inhibitors. It explores the use of infrared spectroscopy and X-ray fluorescence techniques to analyze the chemical composition and structure of the plant extracts, providing insights into their potential as corrosion inhibitors.

Chapter 4 details the experimental methods employed in the research and presents a comprehensive discussion of the results obtained. It describes the experimental setup, the preparation of plant extracts, and the analysis of the corrosion inhibition data. The chapter examines the effects of inhibitor concentration, exposure period, and temperature on the corrosion rate of aluminium in hydrochloric acid. It also includes a scanning electron microscopic study to visualize the surface morphology of the aluminium samples after exposure to the corrosive environment.

Schlüsselwörter

The keywords and focus themes of the text encompass corrosion inhibition, aluminium, hydrochloric acid, natural plant extracts, Azadirechta indica, Murraya koenigii, green inhibitors, weight loss method, inhibitor concentration, exposure period, temperature, scanning electron microscopy, and mechanism of action.

• Course: MSc
• Grade: 3
• Authors: Dr. Vijay Ram et al. (Author), Meera (Author), Pravin N. Ram (Author), Dr. Taslim Ahemad T. Khatri (Author), Dr. Pragnesh N. Dave (Author)
• Publication Year: 2014
• Pages: 94
• Catalog Number: V279280
• ISBN (eBook): 9783656730811
• ISBN (Book): 9783656730804
• Language: English
• Tags: corrosion, inhibition, aluminium, hydrochloric, acid, natural, plant, extracts