Investigation of Thermal and Tribological Behaviour of Oil Dispersed Oleic Acid-Functionalized CuO Nano-Particles in Gear Oil Nano-Lubricants

Nano-fluids are the new class of engineered fluids developed by dispersing nano-additives in base lubricants to enhance the thermal and tribological properties. In the present study, the CuO nano-fluids were prepared by dispersing oleic acid (OA) functionalized nano-particles in gear oil lubricants and have been tested for their performance evaluation in terms of friction, wear, and extreme pressure behavior. However, the effect of thermal conductivity on tribological performance at higher load was also investigated. The two-step method was used to formulate the CuO nano-fluids and OA was used as a surface functionalizing agent. Analytical techniques like FTIR, XRD, DLS, SEM, and EDX were used to investigate the characteristic properties of CuO nanoparticles. The sedimentation method and Induced Couple Plasma (ICP) technique were used to determine the dispersion stability of nano-fluids over 3 months. Further, KD2 Pro thermal conductivity analyzer was used to examine the thermal conductivity of nano-fluids. The findings reveal that the functionalized CuO nano-particles significantly improved the tribological properties of gear oil lubricants. Further, the enhancement in thermal conductivity reduced the contact temperature at a higher load and prevents seizure. The comparative assessments confirmed that CuO nanoparticles can be used as lubricant additives for gear oil lubricants.

Diversified copper sulfide (Cu2-xS) micro-/nanostructures: a comprehensive review on synthesis, modifications and applications

As a significant metal chalcogenide, copper sulfide (Cu_2-xS, 0 < x < 1), with a unique semiconducting and nontoxic nature, has received significant attention over the past few decades. Extensive investigations have been employed to the various Cu_2-xS micro-/nanostructures owing to their excellent optoelectronic behavior, potential thermoelectric properties, and promising biomedical applications. As a result, micro-/nanostructured Cu_2-xS with well-controlled morphologies, sizes, crystalline phases, and compositions have been rationally synthesized and applied in the fields of photocatalysis, energy conversion, in vitro biosensing, and in vivo imaging and therapy. However, a comprehensive review on diversified Cu_2-xS micro-/nanostructures is still lacking; therefore, there is an imperative need to thoroughly highlight the new advances made in function-directed Cu_2-xS-based nanocomposites. In this review, we have summarized the important progress made in the diversified Cu_2-xS micro-/nanostructures, including that in the synthetic strategies for the preparation of 0D, 1D, 2D, and 3D micro-/nanostructures (including polyhedral, hierarchical, hollow architectures, and superlattices) and in the development of modified Cu_2-xS-based composites for enhanced performance, as well as their various applications. Furthermore, the present issues and promising research directions are briefly discussed.

Preparation and adsorption capacity of porous MoS2nanosheets

MoS₂nanosheets with higher adsorption capacity for dyes.