Eco-Friendly Lubricant Developed Using Modified g-C3N4 Enhances Efficiency and Sustainability

In a significant stride toward sustainable industrial practices, scientists from the Institute of Advanced Study in Science and Technology (IASST), Guwahati, have engineered a high-performance, eco-friendly lubricant. The novel formulation integrates chemically modified graphitic carbon nitride (g-C₃N₄) nanosheets into bio-based castor oil, delivering exceptional results in reducing friction and wear in mechanical systems. This innovation promises to be a viable alternative to traditional lubricants, which are often petroleum-based and environmentally hazardous.

The Challenge of Conventional Lubricants

Lubricants play a crucial role in reducing friction and wear between moving parts in machinery, enhancing operational efficiency, and extending equipment lifespan. However, most commercial lubricants are derived from mineral oils or synthetic bases, which are non-biodegradable, toxic, and contribute to environmental pollution during production, usage, and disposal. As industries increasingly seek greener alternatives, the development of bio-based, non-toxic lubricants that do not compromise on performance has become a top priority.

Research Led by IASST

The IASST team, under the leadership of Prof. Devasish Chowdhury, embarked on this mission to innovate a more sustainable lubricant solution. Collaborators included Ujjibit Boruah (INSPIRE Junior Research Fellow), Bitupan Mohan (UGC Junior Research Fellow), and Dr. Nabajit Dev Choudhury from Assam Science and Technology University (ASTU). Their research, recently published in ACS Applied Nano Materials, focused on enhancing the tribological performance (study of friction, wear, and lubrication) of a naturally sourced oil.

Surface-Modified g-C₃N₄: The Game-Changing Additive

The team employed graphitic carbon nitride (g-C₃N₄), a 2D material known for its chemical stability, mechanical strength, and photocatalytic properties. To overcome its inherent incompatibility with oils, the researchers modified the surface of g-C₃N₄ nanosheets using octadecyltrichlorosilane (OTCS), a chemical agent that significantly improved their dispersibility and interaction within the castor oil medium.

This modification allowed the nanoparticles to remain stably suspended in the oil, thereby ensuring consistent lubrication and superior performance over time.

Outstanding Tribological and Thermal Results

When evaluated for tribological performance, the bio-based lubricant demonstrated a 54% reduction in friction and a 60.02% decrease in wear volume compared to plain castor oil. These results underline the formulation’s potential in reducing mechanical losses and extending the lifespan of machinery components.

In addition to tribological efficiency, the lubricant also exhibited enhanced thermal stability. The oxidation onset temperature — a key indicator of thermal resilience — increased from 320°C to 339°C, highlighting the lubricant’s ability to perform effectively under high-temperature operating conditions.

Safety and Environmental Compatibility

One of the remarkable aspects of the formulation is its eco-safety. Toxicity evaluations revealed minimal formation of free radicals, which is crucial for applications in sensitive environments where chemical stability is paramount. Reduced free radical activity ensures that the lubricant does not contribute to unwanted secondary chemical reactions, making it safe for broader industrial and ecological applications.

Toward a Greener Future in Lubrication

“This sustainable lubricant formulation not only enhances mechanical performance but also aligns with global efforts toward green and efficient lubrication technologies,” noted Prof. Chowdhury. The work underscores the possibility of achieving high efficiency in lubrication without compromising environmental health.

As industries continue transitioning toward greener operations, innovations such as this one from IASST offer a blueprint for combining performance with sustainability. The research not only represents a technical triumph but also reinforces India's role in advancing environmentally responsible scientific solutions.