Design, Tribological behavior and mechanism of solvent-free bamboo-derived biochar (BDB)@ZIF-8 nanofluid for enhancing UV-Cured epoxy-acrylate photosensitive resin composites

Abstract

An innovative solvent-free route was developed for fabricating bamboo-derived biochar @Zeolitic Imidazolate Framework-8 nanofluids (code as: BDB@ZIF-8 NFs) via electrostatic assembly of BDB with ZIF-8, culminating in the covalent conjugation of a KH560-M2070 outer shell. The resulting NFs exhibited liquid-like behavior and hybrid organic-inorganic characteristics, leading to an excellent dispersibility within epoxy resin matrix. A comparative study on the tribological performance of resin composites reinforced with various fillers revealed that the BDB@ZIF-8 NFs provided the most significant enhancement. The synergy between the BDB@ZIF-8 core and its KH560-M2070 shell underpins this enhanced performance. The possible mechanisms are as follows: BDB and ZIF-8 act as fillers and rollers on the worn surface, thereby decreasing resin wear. Meanwhile, owing to the presence of the nanofluid, the friction mode during relative motion shifts from dry friction to boundary friction, resulting in a reduced friction coefficient (COF). On the other hand, a dual transfer film composed of iron oxides, a carbon-rich film derived from BDB nanosheets, and a liquid phase is squeezed out of the matrix onto the worn surface. These films collectively enhance the lubricity and durability of the composite.