A PROCESS FOR CORROSION PREVENTION OF COPPER USING WASTE LADY FINGER CAPS

Abstract

The invention discloses an eco-friendly process for preventing copper corrosion in saline environments using an ethanol-based extract derived from waste lady finger caps. The extract, rich in biomolecules like phenolics and flavonoids, forms a robust protective coating on copper surfaces through a simple drop-casting technique. Enhanced with nickel oxide nanoparticles, the coating offers improved mechanical strength, hydrophobicity, and corrosion resistance. The method achieves up to 96% efficiency, validated through electrochemical and surface analyses, promoting sustainability by converting agricultural waste into a valuable resource for industrial applications.

Specification

Description:FIELD OF THE INVENTION:
The present invention relates to the field of corrosion prevention techniques, specifically to the use of waste-derived organic coatings. It focuses on developing eco-friendly, cost-effective protective layers using lady finger caps extract with or without nanoparticles to enhance the corrosion resistance of copper in saline environments.

BACKGROUD OF THE INVENTION:
Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
Copper is one of the most widely used metals in engineering and industrial applications due to its exceptional properties, including high thermal and electrical conductivity, corrosion resistance, and antimicrobial characteristics. Its applications span from electrical wiring and plumbing to heat exchangers and medical equipment. Despite its utility, copper is prone to corrosion when exposed to aggressive environments, particularly those containing chloride ions, such as saline water. Corrosion not only deteriorates copper's structural integrity but also leads to significant economic and environmental losses, necessitating the development of effective protective measures.
Corrosion prevention techniques traditionally involve coatings, inhibitors, or material modifications to shield the metal from its surrounding environment. Coatings serve as a barrier between the metal surface and the corrosive medium, preventing the interaction that leads to degradation. While numerous coating techniques, such as chemical vapor deposition, atomic layer deposition, and electroplating, provide high-quality protective layers, they often involve complex procedures, high costs, or toxic chemicals. Therefore, there is a growing interest in adopting eco-friendly and economically viable alternatives for corrosion prevention.
The use of natural organic materials in corrosion prevention has gained traction due to their biodegradability, abundance, and environmentally benign nature. These materials, often derived from plant-based sources, contain biomolecules such as flavonoids, phenolic compounds, and polysaccharides, which can form a strong adhesive bond with the metal surface. This adhesion helps create a uniform protective layer that reduces the rate of corrosion. However, the effectiveness of these materials can vary depending on their composition and interaction with the substrate. Recent studies have also explored the use of waste organic materials, which are abundant, inexpensive, and sustainable alternatives to conventional corrosion prevention methods.
Lady finger caps, classified as agricultural waste, are typically discarded during food preparation. Rich in biomolecules such as phenolics, flavonoids, and polysaccharides, these caps possess potential for use as a corrosion-resistant coating material. Their molecular structure allows them to form bonds with metal surfaces, creating a thin, adherent layer that serves as a barrier against corrosive agents. Utilizing waste materials like lady finger caps not only addresses the problem of agricultural waste management but also provides an economical solution for corrosion prevention.
The present invention focuses on extracting biomolecules from waste lady finger caps using ethanol and applying them as a protective coating on copper substrates. The extraction process involves drying, crushing, and treating the caps with ethanol to isolate the active compounds. The resulting extract is then applied to the copper surface using the drop-casting technique, which is a simple and cost-effective method for generating thin coatings. Multiple layers of the extract are applied to enhance the surface coverage and protection efficiency.
The corrosion resistance of the coated copper is evaluated in a saline environment (0.5 M NaCl), simulating real-world exposure conditions. Various electrochemical techniques, including open-circuit potential monitoring, Tafel polarization, and electrochemical impedance spectroscopy, are used to assess the performance of the coatings. These methods provide insights into the protective properties of the extract by measuring parameters such as corrosion potential, current density, and charge transfer resistance. Surface analyses, conducted using techniques like field emission scanning electron microscopy and atomic force microscopy, further validate the effectiveness of the coatings in preventing corrosion.
To enhance the performance of the coatings, nickel oxide nanoparticles are incorporated into the extract. Nanoparticles have been shown to improve the mechanical and chemical properties of coatings, increasing their effectiveness in corrosion prevention. Nickel oxide nanoparticles, in particular, are known for their stability, low toxicity, and ability to enhance barrier properties. By mixing varying amounts of nanoparticles into the extract, the invention explores the optimal composition for achieving maximum corrosion resistance. The results indicate that the addition of nanoparticles significantly improves the protective properties of the coatings, with the best performance observed for three layers of extract containing 4 mg of nanoparticles.
The invention also investigates the hydrophobicity of the coated surfaces, as water repellency plays a critical role in corrosion prevention. Water contact angle measurements reveal that the extract coatings increase the hydrophobic nature of the copper surface, further reducing its susceptibility to corrosion. The addition of nanoparticles enhances this effect, resulting in a more pronounced improvement in hydrophobicity. These findings highlight the dual functionality of the coatings in providing both a physical barrier and water repellency.
A key aspect of the invention is its sustainability and environmental impact. By utilizing waste materials and non-toxic solvents, the process aligns with the principles of green chemistry and sustainable development. The low-cost extraction and application methods make it feasible for large-scale implementation, particularly in industries where copper components are exposed to harsh environments. Furthermore, the use of agricultural waste addresses the issue of resource utilization, contributing to a circular economy.
The effectiveness of the coatings is supported by comprehensive electrochemical and surface analyses. The results demonstrate that the extract coatings provide significant protection against corrosion, with the performance improving with the number of layers up to a saturation point. The addition of nanoparticles further enhances the protection by increasing surface coverage and reducing the diffusion of corrosive agents. The invention also provides insights into the mechanisms of corrosion prevention, including the role of biomolecules in forming adhesive bonds with the copper surface and the barrier effect of the coatings.
While the invention primarily focuses on copper, the concept can be extended to other metals and alloys, broadening its applicability. The versatility of the drop-casting technique and the tunability of the coating composition make it a promising approach for addressing corrosion-related challenges in various industries. The findings also open avenues for exploring other agricultural wastes as potential sources of corrosion-resistant coatings, further expanding the scope of sustainable materials research.
Therefore, the invention presents a novel and sustainable approach to corrosion prevention using waste lady finger caps. By leveraging the biomolecules present in the caps and enhancing their properties with nickel oxide nanoparticles, the invention achieves high levels of corrosion resistance in saline environments. The simplicity, cost-effectiveness, and environmental benefits of the process make it a viable alternative to conventional methods, with potential applications across diverse sectors. This work not only addresses the pressing issue of copper corrosion but also contributes to the broader goal of developing eco-friendly solutions for industrial challenges.


OBJECTS OF THE INVENTION:
The prime object of the invention is to provide an eco-friendly and cost-effective method for preventing copper corrosion in saline environments by utilizing waste lady finger caps. This addresses the need for sustainable corrosion prevention techniques that reduce environmental impact while maintaining high efficiency.
Another object of the invention is to formulate a protective coating using ethanol-extracted biomolecules from lady finger caps, which adhere strongly to copper surfaces and create an effective barrier against corrosive agents. The invention aims to utilize agricultural waste as a valuable resource, aligning with the principles of green chemistry and resource sustainability.
Yet another object of the invention is to enhance the corrosion prevention efficiency of the coatings by incorporating nickel oxide nanoparticles. The addition of nanoparticles is intended to improve the mechanical and chemical properties of the coatings, including increased hydrophobicity and reduced permeability to corrosive agents.
Still another object of the invention is to develop a simple, economical, and scalable application process for the coatings using the drop-casting technique. This method ensures ease of implementation without the need for complex equipment, making it accessible for widespread industrial use.
A further object of the invention is to explore the optimal composition and layering of the coatings to maximize their protective performance. By systematically varying the number of layers and the concentration of nanoparticles, the invention aims to achieve the highest levels of corrosion resistance.
An additional object of the invention is to evaluate the hydrophobic nature of the coated surfaces and its role in corrosion prevention. By measuring water contact angles, the invention seeks to demonstrate the dual functionality of the coatings in providing both a physical barrier and enhanced water repellency.
Yet a further object of the invention is to contribute to the circular economy by converting waste materials into functional products, thereby addressing the dual challenges of waste management and corrosion prevention. This approach aims to promote sustainable industrial practices while reducing the environmental footprint.
Still a further object of the invention is to provide a corrosion prevention method that is versatile and adaptable for use with other metals and alloys, extending the scope of its application to various industries and exposure conditions.
The invention thus aims to offer an innovative, sustainable, and effective solution to the problem of copper corrosion, combining scientific advancements with environmental consciousness for industrial and societal benefit.

SUMMARY OF THE INVENTION:
The present invention offers an innovative and eco-friendly approach to addressing the pervasive problem of copper corrosion in saline environments. By utilizing waste lady finger caps, an agricultural by-product often discarded during food preparation, the invention transforms waste into a highly effective, sustainable solution for corrosion prevention. This method not only reduces environmental pollution but also provides a low-cost alternative to conventional anti-corrosion techniques.
An inventive aspect of the invention is to provide a corrosion-resistant coating derived from ethanol-extracted compounds of waste lady finger caps. These extracts are rich in natural biomolecules such as phenolics, flavonoids, and polysaccharides, which demonstrate a strong affinity for copper surfaces. By forming chemical bonds with the metal, these biomolecules create a robust and adherent protective layer that significantly reduces the interaction of copper with corrosive agents in saline environments.
Another inventive aspect of the invention is to enhance the corrosion resistance of the coatings by incorporating nickel oxide nanoparticles into the extract. These nanoparticles not only improve the mechanical strength of the coatings but also fill surface imperfections, thereby minimizing exposure of the substrate to corrosive elements. The nanoparticles further enhance the hydrophobic nature of the coatings, making them more effective in repelling water and reducing the penetration of chloride ions, which are primary contributors to copper corrosion in saline environments.
Yet another inventive aspect of the invention is to simplify the coating application process by employing the drop-casting method. This technique is cost-effective, requires minimal setup, and is scalable for industrial applications. It ensures the formation of thin, uniform coatings on copper surfaces. The process involves depositing layers of the ethanol extract on the substrate, followed by drying at room temperature, enabling easy implementation across various industries without the need for sophisticated equipment or complex procedures.
Still another inventive aspect of the invention is the systematic optimization of the coating's performance through controlled variations in the number of layers and nanoparticle concentrations. The results demonstrate that the highest corrosion resistance is achieved with three layers of the extract combined with 4 mg of nickel oxide nanoparticles. This configuration provides up to 96% efficiency in corrosion prevention, as validated through electrochemical techniques such as open circuit potential, Tafel polarization, and electrochemical impedance spectroscopy. These findings highlight the critical balance between layer thickness, nanoparticle concentration, and surface coverage in achieving optimal protection.
An additional inventive aspect of the invention is to enhance the hydrophobicity of the coated surfaces, as measured by water contact angles. The hydrophobic nature of the coatings is a key feature that complements the barrier effect by repelling water molecules, thereby reducing the likelihood of water-induced corrosion. The incorporation of nickel oxide nanoparticles further increases the water contact angle, reinforcing the coating's ability to resist moisture and other corrosive agents.
Yet a further inventive aspect of the invention is to demonstrate the effectiveness of these coatings in simulated real-world conditions. Through extensive electrochemical testing in 0.5 M NaCl solution, the invention establishes the efficacy of the coatings in reducing the corrosion rate of copper. Additionally, surface analyses using techniques such as field emission scanning electron microscopy and atomic force microscopy confirm the uniformity and adhesion of the coatings, as well as their ability to minimize surface roughness and defect propagation.
Still a further inventive aspect of the invention is its contribution to sustainability and waste management. By converting waste lady finger caps into a valuable resource for corrosion prevention, the invention aligns with the principles of green chemistry and circular economy. It offers an alternative to traditional anti-corrosion methods that often rely on toxic chemicals and non-renewable materials, thus reducing the environmental footprint of corrosion prevention practices.
Another inventive aspect of the invention is the versatility of the proposed solution, which can be adapted to other metals and alloys beyond copper. The adaptability of the extract and nanoparticle composition enables its application in diverse industries, such as marine, automotive, electronics, and construction, where metal corrosion poses significant challenges. This broad applicability enhances the practical value of the invention, making it a universal solution for corrosion-related issues.
An additional inventive aspect is the comprehensive evaluation of the coating's performance through a multi-faceted analysis. Techniques such as UV-Vis and FTIR spectroscopy confirm the presence and uniform distribution of biomolecules and nanoparticles within the extract, while electrochemical impedance spectroscopy and Tafel polarization curves quantify the corrosion resistance provided by the coatings. These scientific validations underscore the reliability and effectiveness of the invention.
A further inventive aspect of the invention is the ability to fine-tune the coatings for specific applications by adjusting the extract-to-nanoparticle ratio and the number of layers. This customization ensures that the protective coatings meet the specific requirements of various industrial and environmental conditions, such as high humidity, saltwater exposure, or chemical interactions.
Finally, the invention addresses the economic aspect of corrosion prevention by offering a cost-effective solution that reduces dependence on expensive synthetic materials and energy-intensive processes. The low-cost extraction process, combined with the simplicity of the drop-casting application, makes the invention accessible to industries and communities with limited resources, providing an affordable means to extend the lifespan of copper components and reduce maintenance costs.
Therefore, the invention integrates innovative scientific principles, sustainable practices, and practical applications to deliver an effective and eco-friendly solution for copper corrosion prevention. By leveraging the natural properties of waste lady finger caps and enhancing their performance with nickel oxide nanoparticles, the invention sets a benchmark for sustainable materials research. It offers a comprehensive and adaptable approach to corrosion protection, balancing environmental considerations with industrial needs, and paving the way for future advancements in green technology.

BRIEF DESCRIPTION OF DRAWINGS:
The accompanying drawings illustrate various embodiments of "A Process for Corrosion Prevention of Copper Using Waste Lady Finger Caps," highlighting key aspects of its formulation and application. These figures are intended for illustrative purposes to aid in understanding the invention and are not meant to limit its scope.
FIG. 1 depicts a schematic representation of the process for extracting ethanol-based lady finger caps (EALFC) and the application of coatings on copper, according to an embodiment of the present invention.
The drawings provided will be further described in detail in the following sections. They offer a visual representation of the extraction process, coating application, and resulting protection efficiency, helping to clarify and support the detailed description of the invention.

DETAILED DESCRIPTION OF THE INVENTION:
In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that the embodiments may be combined, or that other embodiments may be utilized and that structural and logical changes may be made without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims and their equivalents.
The present invention is described in brief with reference to the accompanying drawings. Now, refer in more detail to the exemplary drawings for the purposes of illustrating non-limiting embodiments of the present invention.
As used herein, the term "comprising" and its derivatives including "comprises" and "comprise" include each of the stated integers or elements but does not exclude the inclusion of one or more further integers or elements.
As used herein, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. For example, reference to "a device" encompasses a single device as well as two or more devices, and the like.
As used herein, the terms "for example", "like", "such as", or "including" are meant to introduce examples that further clarify more general subject matter. Unless otherwise specified, these examples are provided only as an aid for understanding the applications illustrated in the present disclosure, and are not meant to be limiting in any fashion.
As used herein, the terms ""may", "can", "could", or "might" be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
Exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. These exemplary embodiments are provided only for illustrative purposes and so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those of ordinary skill in the art. The invention disclosed may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.
Various modifications will be readily apparent to persons skilled in the art. The general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Moreover, all statements herein reciting embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (i.e., any elements developed that perform the same function, regardless of structure). Also, the terminology and phraseology used is for the purpose of describing exemplary embodiments and should not be considered limiting. Thus, the present invention is to be accorded the widest scope encompassing numerous alternatives, modifications and equivalents consistent with the principles and features disclosed. For purpose of clarity, details relating to technical material that is known in the technical fields related to the invention have not been described in detail so as not to unnecessarily obscure the present invention.
Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., "such as") provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition and persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.
With reference to FIG. 1, in an embodiment of the present invention, the present invention provides a comprehensive and eco-friendly approach for preventing corrosion of copper in saline environments by utilizing waste lady finger caps. This innovative process transforms agricultural waste into a functional protective coating, offering significant environmental and economic benefits while maintaining high corrosion resistance. The process begins with the collection and preparation of waste lady finger caps, which are first thoroughly washed using deionized water to remove impurities such as dirt, residues, or other unwanted particles. This step ensures the quality of the final extract and prepares the material for further processing.
The cleaned caps are then dried at a controlled temperature of 50°C for six hours to remove moisture content while preserving the active biomolecules within the caps. After drying, the caps are crushed into a fine powder, enabling a uniform and efficient extraction process. This powdered form ensures maximum surface area for interaction with ethanol, the solvent used for biomolecule extraction. The powdered caps are mixed with ethanol in a predefined ratio and stirred at a constant speed of 400 RPM for six hours. This stirring facilitates the release of biomolecules such as phenolics, flavonoids, and polysaccharides from the plant material into the ethanol solution.
To enhance the extraction efficiency, the stirred mixture undergoes ultrasonic treatment for 30 minutes. Ultrasonication helps break down any remaining solid particles and ensures uniform distribution of biomolecules within the solvent. After ultrasonication, the mixture is filtered using Whatman paper to separate the ethanol-based extract from residual solids. The resulting extract is rich in biomolecules that are known to enhance adhesion and corrosion resistance when applied to metal surfaces.
In preparation for coating application, the copper surfaces are cleaned using emery paper and ethanol. This cleaning process removes any surface impurities, oxidation layers, or irregularities, ensuring optimal adhesion of the coating. Once prepared, the ethanol-based extract is applied to the copper surfaces using a drop-casting technique. In this method, 30 µL of the extract is deposited onto the copper surface to form a uniform layer. After each layer is applied, the coated copper is allowed to dry at room temperature for 15 minutes. This step is repeated to build multiple layers of the coating, with the number of layers optimized for maximum corrosion resistance.
An optional enhancement to the process involves incorporating nickel oxide nanoparticles into the ethanol-based extract before application. These nanoparticles, when added in concentrations ranging from 2 mg to 6 mg, significantly improve the mechanical and barrier properties of the coating. The optimal concentration of 4 mg has been found to provide the highest corrosion resistance by filling microdefects in the coating and increasing its hydrophobic nature. The nanoparticles act as additional barriers to corrosive agents, further reducing the permeability of the coating.
The protective performance of the coating is evaluated using a range of advanced electrochemical techniques. Open-circuit potential measurements assess the coating's ability to shift the corrosion potential of the copper to a less negative value, indicating a protective effect. Tafel polarization curves provide insights into the reduction in corrosion current density, demonstrating the coating's effectiveness in slowing down the corrosion process. Electrochemical impedance spectroscopy is used to measure charge transfer resistance, a key indicator of the coating's barrier properties. Higher resistance values correlate with greater protection against corrosion.
The coated copper surfaces are also analyzed for hydrophobicity, which plays a crucial role in reducing water-induced corrosion. Water contact angle measurements show that the ethanol-based extract increases the hydrophobic nature of the copper surface, with further enhancement observed when nickel oxide nanoparticles are incorporated. Increased hydrophobicity reduces the ability of water and chloride ions to interact with the copper surface, further preventing corrosion.
The structural and surface properties of the coated copper are examined using techniques such as field emission scanning electron microscopy and atomic force microscopy. These analyses confirm the uniformity and adhesion of the coating layers, as well as their ability to reduce surface defects. The microscopy results reveal that the coating effectively covers the copper surface, minimizing exposure to corrosive agents. The addition of nanoparticles is shown to further enhance surface coverage by filling microdefects and irregularities.
The coating achieves maximum corrosion prevention efficiency with three layers of the ethanol-based extract, providing up to 91% protection in the absence of nanoparticles. When 4 mg of nickel oxide nanoparticles is incorporated, the efficiency increases to 96%, demonstrating the synergistic effect of the extract and nanoparticles. Beyond three layers or higher nanoparticle concentrations, the efficiency shows saturation, likely due to limitations in surface coverage and coating compactness.
The use of waste lady finger caps as a source material for corrosion prevention is a significant step toward sustainable industrial practices. By converting agricultural waste into a valuable resource, the invention addresses environmental concerns while reducing the cost of corrosion prevention methods. The ethanol-based extraction process and drop-casting technique are simple, scalable, and cost-effective, making them suitable for industrial applications. The incorporation of nickel oxide nanoparticles adds versatility to the coating, enabling its use in various environments and industries where copper is exposed to corrosive conditions.
The invention also demonstrates adaptability for protecting other metals and alloys. The process and composition can be modified to meet the specific requirements of different substrates and exposure conditions. This versatility extends the potential applications of the invention to sectors such as marine engineering, automotive manufacturing, and construction, where metal corrosion poses significant challenges.
The environmental impact of the invention is minimal, as it uses ethanol as a solvent and waste lady finger caps as the primary material. The optional addition of nickel oxide nanoparticles, known for their low toxicity, further aligns with the principles of green chemistry. The process eliminates the need for toxic chemicals and energy-intensive procedures commonly associated with traditional anti-corrosion methods, making it a safer and more sustainable alternative.
The invention provides a scientifically robust and practical solution for copper corrosion prevention in saline environments. By leveraging the natural properties of biomolecules and the enhancing effects of nanoparticles, the invention achieves high levels of protection while addressing environmental and economic concerns. The comprehensive evaluation of the coating's performance through electrochemical testing, surface analysis, and hydrophobicity measurements underscores its reliability and effectiveness.
Therefore, the process transforms waste materials into functional coatings with high corrosion resistance, minimal environmental impact, and broad applicability. The use of simple yet effective techniques, combined with the innovation of incorporating nanoparticles, sets a new standard for sustainable corrosion prevention methods. This invention not only extends the lifespan of copper components but also contributes to the advancement of eco-friendly technologies in industrial practices.

Working of the invention: The invention operates through a combination of processes and interactions between natural biomolecules, copper surfaces, and optional nickel oxide nanoparticles, resulting in effective corrosion prevention. The working mechanism involves several key steps and principles, as described below:
The process begins with the preparation of an ethanol-based extract from waste lady finger caps. The biomolecules in the caps, including phenolics, flavonoids, and polysaccharides, are extracted through a combination of drying, crushing, mixing, and ultrasonication. These biomolecules are known to form strong chemical bonds with metal surfaces, making them ideal for protective coatings. The ethanol solvent not only acts as an efficient medium for extracting these molecules but also aids in their uniform distribution during application.
The copper surface is pretreated to ensure proper adhesion of the coating. This involves cleaning the surface with emery paper to remove oxidation layers and contaminants, followed by ethanol cleaning to eliminate any residual particles. A clean and smooth copper surface enhances the bonding between the metal and the biomolecules in the extract.
The extract is applied to the copper surface using a drop-casting technique. In this method, small volumes (e.g., 30 µL) of the extract are carefully deposited onto the surface, forming a thin and uniform layer. The layer is then dried at room temperature for 15 minutes to allow the biomolecules to adhere to the surface and create a physical barrier. Multiple layers can be applied to increase the thickness and effectiveness of the coating. Each successive layer corrects any microdefects or imperfections in the underlying layer, enhancing the overall coverage and corrosion resistance.
The optional incorporation of nickel oxide nanoparticles into the extract further improves the coating's performance. These nanoparticles act as fillers, plugging microdefects and enhancing the coating's mechanical strength. They also increase the coating's hydrophobicity, reducing the ability of water and chloride ions to reach the copper surface. The nanoparticles are uniformly distributed within the extract during ultrasonication, ensuring consistent enhancement across the coating.
Once applied, the coating works by forming a dual protective mechanism. Firstly, it creates a physical barrier between the copper surface and the corrosive medium (e.g., saline water). This barrier prevents the direct contact of chloride ions and water molecules with the copper, reducing the electrochemical reactions that lead to corrosion. Secondly, the biomolecules in the coating provide chemical protection by bonding with the copper atoms. These bonds stabilize the surface and reduce the activity of copper, further mitigating corrosion.
The hydrophobic nature of the coating, as evidenced by increased water contact angles, plays a significant role in its effectiveness. The hydrophobic surface repels water molecules, preventing their penetration into the coating and reducing the interaction between the copper surface and the corrosive medium. This property is particularly enhanced by the presence of nickel oxide nanoparticles, which increase the surface's resistance to water-induced corrosion.
The effectiveness of the coating is validated through electrochemical testing. Open-circuit potential measurements show that the coating shifts the corrosion potential of copper to less negative values, indicating reduced susceptibility to corrosion. Tafel polarization curves reveal a significant decrease in corrosion current density, demonstrating the coating's ability to slow down the corrosion process. Electrochemical impedance spectroscopy further confirms the coating's barrier properties by showing increased charge transfer resistance, which correlates with enhanced protection.
The structural integrity and uniformity of the coating are assessed using surface analysis techniques such as field emission scanning electron microscopy and atomic force microscopy. These analyses reveal that the coating forms a smooth and adherent layer on the copper surface, with minimal defects or irregularities. The addition of nickel oxide nanoparticles is shown to improve the coating's compactness and fill any microdefects, resulting in more effective corrosion prevention.
In saline environments, the coating provides long-lasting protection by reducing the rate of copper degradation. The combination of physical and chemical barriers ensures that the copper surface remains shielded from chloride ions and other corrosive agents. The ability to apply multiple layers allows for customization of the coating thickness, enabling it to meet the specific requirements of different applications.
Overall, the invention works by leveraging the natural properties of waste-derived biomolecules and enhancing them with nanoparticles to create a robust, hydrophobic, and environmentally friendly coating. This coating effectively prevents corrosion in copper, extending its lifespan and reducing maintenance costs while contributing to sustainable industrial practices.
The experimental validation of the invention involved a systematic evaluation of the corrosion prevention capabilities of the ethanol-based extract derived from waste lady finger caps, both with and without nickel oxide nanoparticles, applied to copper surfaces. The validation process was designed to assess the efficiency of the coatings under saline conditions (0.5 M NaCl) using advanced electrochemical techniques, surface analysis, and hydrophobicity measurements.
The ethanol extract was prepared by drying, crushing, and ultrasonically treating lady finger caps in ethanol, followed by filtration. Nickel oxide nanoparticles were synthesized separately and incorporated into the extract in varying concentrations (2 mg, 4 mg, and 6 mg) for additional testing. Copper samples were cleaned with emery paper and ethanol to ensure uniform adhesion, and the coatings were applied using the drop-casting technique. Multiple layers (1 to 4) were applied, with each layer dried at room temperature for 15 minutes before adding the next.
Electrochemical Validation
The corrosion resistance of the coated copper was evaluated using open-circuit potential (OCP), Tafel polarization curves (TPC), and electrochemical impedance spectroscopy (EIS).
• OCP Results: The OCP curves demonstrated that the coated copper samples exhibited less negative potentials compared to bare copper. Among the coated samples, three layers of ethanol extract with 4 mg of nickel oxide nanoparticles showed the least negative OCP value, indicating the highest resistance to corrosion.
• TPC Results: Tafel polarization curves revealed a significant reduction in corrosion current density (icorr) for coated samples. The bare copper exhibited an icorr of 5.4 µA/cm², while three layers of ethanol extract reduced the icorr to 0.5 µA/cm², achieving 91% corrosion prevention efficiency. When 4 mg of nickel oxide nanoparticles were added, the icorr further decreased to 0.2 µA/cm², providing 96% efficiency.
• EIS Results: Nyquist plots indicated a substantial increase in charge transfer resistance (Rct) for coated samples compared to bare copper. The Rct for bare copper was 2.1 kO·cm², whereas it increased to 23.2 kO·cm² for three layers of ethanol extract and further to 47.5 kO·cm² with 4 mg of nickel oxide nanoparticles. This data confirmed the enhanced barrier properties of the coatings.
Hydrophobicity Analysis
Water contact angle (WCA) measurements were performed to evaluate the hydrophobic nature of the coated surfaces. The WCA for bare copper was 60.4°, which increased to 70.5° with one layer of ethanol extract. The incorporation of nickel oxide nanoparticles further enhanced the WCA to 73.4°. This increase in hydrophobicity indicates improved water repellency, which plays a crucial role in reducing water-induced corrosion.
Surface Analysis
Field emission scanning electron microscopy (FESEM), optical microscopy, and atomic force microscopy (AFM) were used to examine the surface morphology of the coated and bare copper samples.
• FESEM Analysis: The bare copper surface displayed visible corrosion pits after exposure to 0.5 M NaCl, while the coated samples showed a smooth and intact surface with minimal signs of degradation. The coatings with nickel oxide nanoparticles exhibited better coverage, filling microdefects and providing enhanced protection.
• AFM Analysis: Surface roughness measurements further validated the effectiveness of the coatings. The roughness of bare copper was 65 nm after corrosion, which reduced to 35 nm for three layers of ethanol extract. The addition of nanoparticles lowered the roughness further to 25 nm, indicating a smoother and more uniform protective layer.
Optimization of Coating Parameters
The experimental data highlighted that three layers of ethanol extract provided optimal protection, as additional layers showed marginal improvements and slight reversals in hydrophobicity and corrosion resistance. Similarly, 4 mg of nickel oxide nanoparticles was identified as the optimal concentration for enhancing the extract's protective properties. Higher concentrations led to saturation and minor reductions in efficiency, likely due to aggregation effects.
Summary of Experimental Data
Parameter Bare Copper Ethanol Extract (3 Layers) Ethanol Extract + 4 mg NiO NP (3 Layers)
Corrosion Current Density (µA/cm²) 5.4 0.5 0.2
Charge Transfer Resistance (kO·cm²) 2.1 23.2 47.5
Water Contact Angle (°) 60.4 70.5 73.4
Surface Roughness (nm) 65 35 25
Corrosion Prevention Efficiency (%) - 91 96

The experimental validation confirms the effectiveness of the invention in preventing copper corrosion in saline environments. The ethanol-based extract provides significant protection, which is further enhanced by the incorporation of nickel oxide nanoparticles. The coatings not only create a robust physical barrier but also improve hydrophobicity, reducing the interaction between the metal surface and corrosive agents. The results demonstrate the invention's potential for industrial applications while promoting sustainability by utilizing agricultural waste.

ADVANTAGES OF THE INVENTION:
The prime advantage of the invention is to provide an eco-friendly and sustainable method for preventing copper corrosion, utilizing waste lady finger caps as a resource, thereby promoting waste valorization and environmental conservation.
Another advantage of the invention is its cost-effectiveness, as it uses readily available agricultural waste and simple processing methods, making it a viable solution for industries with limited resources.
Yet another advantage of the invention is the enhanced corrosion resistance achieved by the ethanol extract, which creates a robust protective barrier on copper surfaces, significantly reducing the interaction with corrosive agents.
Still another advantage of the invention is the incorporation of nickel oxide nanoparticles, which improves the coating's mechanical strength, hydrophobicity, and barrier properties, further enhancing its performance against corrosion.
An additional advantage of the invention is its scalability and simplicity, as the drop-casting technique allows for easy application of the coatings without requiring complex or costly equipment.
A further advantage of the invention is its adaptability for different environmental conditions and metals, offering a versatile solution that can be tailored for various industrial applications.
Yet a further advantage of the invention is the reduction in water-induced corrosion, achieved through increased hydrophobicity of the coated surface, effectively repelling moisture and chloride ions.
Another key advantage of the invention is its compliance with green chemistry principles, minimizing environmental impact by using non-toxic materials and processes, thereby ensuring safety and sustainability.
An added advantage of the invention is the reduction of maintenance and replacement costs for copper components by extending their service life through effective corrosion prevention.
Lastly, the invention contributes to advancing sustainable industrial practices by combining eco-friendly materials and innovative engineering, addressing global challenges of waste management and corrosion simultaneously.
, Claims:CLAIM(S):
We Claim:
1. A process for preventing corrosion of copper in saline environments, comprising:
a) collecting waste lady finger caps and washing them thoroughly with deionized water to remove impurities;
b) drying the caps at a controlled temperature of 50°C for 6 hours and crushing them into a fine powder;
c) mixing the powdered caps with ethanol in a predefined ratio to extract biomolecules, followed by stirring the mixture at 400 RPM for 6 hours;
d) ultrasonically treating the mixture for 30 minutes to enhance the extraction efficiency and filtering it using Whatman paper to obtain a pure ethanol-based extract;
e) preparing copper surfaces by cleaning them with emery paper and ethanol to ensure proper adhesion of the coating;
f) applying 30 µL of the ethanol-based extract onto the copper surface using a drop-casting technique to form uniform layers, with drying intervals of 15 minutes at room temperature between successive layers; and
g) optionally incorporating nickel oxide nanoparticles into the extract before application to improve the mechanical and corrosion resistance properties of the coating.
2. The process of claim 1, wherein the ethanol-based extract contains biomolecules such as phenolics, flavonoids, and polysaccharides, which enhance adhesion and corrosion resistance.
3. The process of claim 1, further comprising the addition of nickel oxide nanoparticles to the ethanol-based extract to improve the mechanical and barrier properties of the coating.
4. The process of claim 3, wherein the concentration of nickel oxide nanoparticles ranges from 2 mg to 6 mg, with 4 mg providing optimal corrosion resistance.
5. The process of claim 1, wherein three layers of the extract provide maximum corrosion prevention efficiency, achieving up to 91% in the absence of nanoparticles and up to 96% when combined with 4 mg of nickel oxide nanoparticles.
6. The process of claim 1, wherein the coated copper exhibits increased hydrophobicity, as indicated by water contact angle measurements, reducing susceptibility to water-induced corrosion.
7. The process of claim 1, wherein the corrosion prevention is evaluated using electrochemical techniques including open-circuit potential, Tafel polarization, and electrochemical impedance spectroscopy.
8. The process of claim 1, wherein the coating application ensures reduced surface defects and enhanced adhesion, as confirmed by field emission scanning electron microscopy and atomic force microscopy analyses.
9. A protective coating for copper, formulated from ethanol-extracted biomolecules of waste lady finger caps, optionally combined with nickel oxide nanoparticles, providing a hydrophobic and corrosion-resistant barrier in saline environments.
10. The protective coating of claim 9, wherein the incorporation of nickel oxide nanoparticles enhances surface coverage and corrosion prevention efficiency by improving the mechanical integrity and reducing permeability to corrosive agents.

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