Applications and Future Innovations in Nanomaterials-Based Corrosion Inhibitors for Sustainable Development in 21st Century

Introduction

Corrosion is the electrochemical oxidation of metals, ceramics, polymers, and other industrially important materials when exposed to the atmosphere. It leads to the degradation of the physical and chemical characteristics of the materials, viz., lustre, mechanical strength, appearance, permeability, ductility, hardness, etc. Corrosion is a significant concern in industries such as oil and gas, automotive, aerospace, and infrastructure, leading to economic losses and safety hazards. (The Electrochemical Society, n.d.) Transportation, logistics, electronics, oil and gas, water transportation, construction, energy, and other key infrastructural sectors experience serious damage due to corrosion. According to the Indian Stainless Steel Development Authority, India incurs a loss of around 110 billion USD annually due to corrosion. (The Economic Times, 2023) The corrosion also leads to serious public safety concerns by damaging the durability of the roads, bridges, railway tracks, ports, and other important public constructions. Moreover, the corrosion also causes leakage in pipelines that affects the water supply mechanism. The leakage in oil pipes may result in the emission of hazardous chemicals, contaminating the environment and ecosystem. Corrosion also has a serious impact on the modern electronic industry. The lifespan of the electronic devices may be reduced due to the malfunctioning of the metallic parts induced by corrosion. Furthermore, the damage to key infrastructural facilities due to corrosion increases the maintenance and repair costs, causing a hike in public expenditure. (Sharma, 2023) Traditional corrosion inhibitors, while effective to some extent, often pose environmental and health risks. The chemical-based coating materials contain organic and inorganic toxicants that pose serious environmental issues. The emission of zinc fumes during the galvanization of metallic substances causes air pollution. The chemicals used to manufacture anti-corrosive alloys also possess serious environmental impacts. Moreover, the traditional processes of corrosion inhibition require periodic maintenance, imposing an excess financial burden. (Collins, n.d.)

Nano-materials, with their tailored properties, offer an innovative approach to corrosion inhibition. Nanomaterials exhibit unique properties due to their nanoscale dimensions, including a high surface area-to-volume ratio, quantum effects, and surface energy. These properties influence their effectiveness as corrosion inhibitors. Various nano-materials, such as nanoparticles, nanotubes, and nanostructured coatings, have been explored for corrosion inhibition. Mechanisms of inhibition include barrier protection, surface passivation, and active corrosion inhibition through the release of corrosion-inhibiting species. Nanomaterial innovations for corrosion inhibition present promising opportunities for mitigating corrosion-related issues across various industries. Graphene, a two-dimensional material with extraordinary mechanical, electrical, and chemical properties, has gained significant attention in corrosion inhibition. Nanostructured ceramics offer enhanced corrosion resistance due to their high surface area and tailored properties. Metallic organic frameworks are a class of porous materials with tunable structures and high surface areas, making them promising candidates for corrosion inhibition. Nanostructured polymers offer versatility in design and application, providing tailored corrosion protection for various substrates. Carbon Nanotubes and nanofibers possess high mechanical strength and electrical conductivity, making them suitable for corrosion protection in aggressive environments. Nanostructured metal coatings improve corrosion resistance by enhancing grain refinement and tailored surface properties. Customising the surface chemistry of nanomaterials through functionalization makes it easier for them to stick to metal surfaces and makes them better at stopping corrosion. Incorporating nano-materials with self-healing properties into coatings offers a proactive approach to corrosion protection by autonomously repairing damage and extending the service life of protective coatings. Controlled release of corrosion inhibitors from nanomaterials in response to environmental stimuli such as pH, temperature, or corrosion onset offers targeted protection and minimises the need for continuous reapplication. Integration of multiple nanomaterials into composite structures allows for synergistic effects, combining corrosion inhibition with other functionalities such as mechanical reinforcement or antimicrobial properties. (Jain et. al., 2020)