Green and Scalable Design of Plant-Based MoS2-OA Pickering Nanofluids for Simultaneous Friction Reduction and Heat Dissipation in Sustainable Metalworking

Traditional mineral oil-based cutting fluids are increasingly incompatible with sustainable manufacturing due to their environmental and health impacts. To solve these challenges, this work presented a green and scalable strategy for a high-performance nano-cutting fluid by constructing a plant-based Pickering emulsion. This system innovatively utilized cottonseed oil as the base oil, stabilized by oleylamine (OA) modified MoS 2 nanosheets (MoS 2 -OA) at the oil-water interface. The formulation was rationally designed and optimized by response surface methodology (RSM) to synergistically enhance emulsion stability, lubrication, and heat dissipation. The resulting Pickering emulsion is demonstrated to possess a unique combination of significantly reduced friction and wear, along with improved thermal conductivity, outperforming a commercial cutting fluid. Mechanistic analysis revealed that MoS 2 -OA nanosheets formed a multifunctional interfacial film, which synergistically served as a “lubrication film” for low friction and a “thermal bridge” for efficient heat dissipation. Thus, a novel paradigm for developing sustainable metalworking fluids is established by leveraging the synergistic potential of non-edible plant oils and functional nanomaterials.