Tribological performance of freeze-drying nano-copper particle as additive of paroline oil

Abstract

Monodispersed nano-copper particles were prepared, and the optimized method of preparation procedure was established through orthogonal experiments under four different factors. The experimental results show that the particle size of freeze-dried nano-copper particles can be adjusted by rotational speed, freezing rate, types of active agents and freezing mode, and freezing mode is the most important among all of the four factors. Tribological results of the nano-copper particles from the best optimized procedure can be improved 5%-10% than that of pure paroline oil and the lowest coefficient of friction 0.12 can be obtained for the sample of 0.05 wt%. The lubrication mechanism mostly attributed to the appropriate concentration of copper particles filling the surface pits, which is beneficial for the improvement of the tribological performance.

Effects of Span 60 template and freeze drying on zinc borate produced from zinc nitrate hexahydrate and borax decahydrate

“…However nano particles also agglomerated even drying of the ethanol washed hydrogel. Since silver, [17] copper, [18] alumina, [21] B 2 O 3 precursor [22] and polycaprolactone [23] nanoparticles were obtained successfully by freeze drying, freeze drying of the zinc borate nano particles would allow drying without agglomeration of nano zinc borate particles.…”

“…), as well as completing by freeze drying. [18] Tachiwaki et al [19] produced the fine powders for the YBCO superconductor by freeze-drying of the suspensions synthesized by co-precipitation of carbonates. Zeng et al used AlCl 3 Á6H 2 O and ammonia as precursor materials to precipitate boehmite (c-AlO(OH)) in aqueous solution, peptized boehmite to a transparent sol with nitric acid and then freeze dried the sol.…”

Tribological properties of lyophilized graphene loading nano-copper as lubricating oil additive

“…In recent years, inorganic nanoparticles prepared by lyophilization have a large number of studies that show lyophilization have the benefits of high purity, good dispersion, large specific surface area and small particle size effect. Meanwhile, the size of the nanoparticle can be regulated under different process conditions (Zhecheva et al , 2010; Hu et al , 2021; Bovone et al , 2016; Peng et al , 2016; Yin et al , 2018; Peng et al , 2020). Therefore, to obtain nanoparticles with low agglomerates and uniform dispersion, this paper uses reduced graphene oxide (RGO) and RGO/Cu powders prepared by the lyophilization method to investigate the synergistic friction reduction and antiwear effects.…”

Preparation of graphene‐loading copper nanoparticles by freeze drying and its tribological properties

“…It is widely used in the field of lubrication additives. [11][12][13][14][15] Nevertheless, nano additives generally have the problems of large surface energy and easy agglomeration.…”

“…It can repair the micro‐damaged parts of friction pairs and play the role of ball bearings effect in the sliding process. It is widely used in the field of lubrication additives 11–15 . Nevertheless, nano additives generally have the problems of large surface energy and easy agglomeration.…”