Tribological behavior of 3D printed nanofluid reinforced photosensitive self-lubricating polymer materials

Oil-loaded polymer composites have become a research focus in tribology due to the good environmental stability and excellent performance. Usually, it is necessary to endow the polymer with a porous structure to facilitate lubricating oil storage. However, most methods require complex operating steps, making it difficult to control the complex shape of materials, and excessive pores often lead to an imbalance between the oil storage and retention rates. At the same time, the mechanical properties of the material can also be negatively affected. Developing a simple synthesis method to obtain oil-loaded polymer composite materials with good self-lubricating and mechanical properties still faces challenges. Herein, a one-pot synthesis method for oil-loaded self-lubricating polymers was proposed, which embeds the porous silica nanoparticles loaded with lubricating oil into the polymer and uses vat photopolymerization-based technologies to construct the polymer with various complex and delicate structures. After a series of treatments, such as photocuring and cleaning, an oil-loaded polymer-based composite material with good self-lubricating performance was prepared. Benefiting from the rich mesoporous pore structure of mesoporous silica, high specific surface area of 467 m2g−1, and pore volume of 1.06 cm3g−1, the oil content and retention rate of the composite materials are at a high level. In addition, by combining oil-loaded mesoporous silica nanoparticles with 3D printing, controllable preparation of complex shapes of self-lubricating composite materials has been achieved. During the friction performance testing process, the oil-loaded particles in the polymer composite can continuously provide lubricating oil on the friction surface, thus making the friction coefficient and wear rate reduced by 85.7% and 97.7%.