Nowadays, many efforts have been made to minimise the pollution risks of copper electroplating effluent, such as chemical methods, physical methods, etc. Among them, chemical reduction has been used in this paper for its simplicity and potential for industrial production, and the recovered Cu nanoparticles (CuNPs) were innovatively used as a lubricant additive to prolong the lifetime of lubrication equipment and enhance energy conservation via emission reduction. In this paper, the relationships of the remaining Cu 2z concentration ([Cu 2z ]) with NaBH 4 /CuSO 4 mole ratio, reaction time and reaction temperature were discussed separately. Then, L 9 (3 3 ) orthogonal experiment was carried out to determine optimal reaction conditions. Finally, the tribological behaviours [e.g. friction coefficients (FCs) and wear scar diameter (WSD)] of base oil samples with and without addition of the recovered CuNPs were investigated. Results indicate that the optimal reaction conditions were as follows: NaBH 4 /CuSO 4 (4 : 6) react at 30uC for 25 min, under which [Cu 2z ] was minimised to 0?2 mg L 21 with a mean particle size of 33 nm. The FC and WSD of oil with 0?3 wt-%CuNPs were decreased by 33?4 and 19% respectively compared with the base oil. This compound oil was much more suitable for moderate load and high load than for low load. This paper provides a new idea on dealing with the copper electroplating effluent.

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For the development of complex calcium sulfonate grease containing ultrafine SiO2/MoS2 powders with self-reparing performance. On the basis of the dispersion of the nanoSiO2 particles, the effects of particle size,addition amount,load and the mass ratio of nanoSiO2 to ultrafine MoS2 powders on the tribological properties of commercial No.2 complex calcium sulfonate grease were systematically studied by four ball friction and wear tester. The results show that suitable particle size and addition amount of single SiO2 and MoS2 powders can significantly reduce the coefficient of friction (COF) and the wear scar diameter (WSD) of the grease. The composite of nanoSiO2 and MoS2 powder can broaden the load range of base grease and further improve the tribological properties of complex calcium sulfonate grease. When the mass ratio of nanoSiO2 powder to MoS2 powder is 3:7 and the total addition amount is 0.8wt%, the COF and the WSD of the grease are decreased by 53.64% and 27.08%, respectively, compared with the base grease. The two powders in the composite grease have synergy effect for improving the tribological performance and the friction stability of the grease during the process of long friction.

The micro-nanostructures were prepared on the surface of 304 stainless steel by one-step anodizing with perchloric acid-ethylene glycol electrolyte. The morphologys, phase behaviour and microstructures of the prepared micro-nanostructures were characterized by SEM, XRD and metallographic examinations. The corrosion resistance and hydrophobic properties of 304 stainless steel after anodizing at different times were studied by Tafel test and contact angle test. The results show that when the anodization voltage is 30V, the electrolyte is 5vol% perchloric acid-ethylene glycol, the reaction temperature is 0 ± 5 ° C，and the anodization time is 15min, a honeycomb micro-nanostructure having an average pore diameter of 143 nm, an average pore spacing of 124 nm and a uniform distribution can be prepared on the surface of 304 stainless steel. The prepared nanostructure has a contact angle with water of 128° and a hydrophobicity of 86.3%, which corrosion resistance is 21 times higher than that of ordinary 304 stainless steel in 3.5 wt% NaCl solution. Metallographic microscopic observation and XRD indicate that the anodic oxidation begins along the grain boundary of the austenite, and then the micro-nano holes grow on the austenite and fill the entire austenite phase. Finally, Fe2O3 structure with uniformly distributed micro-nano pores is formed on the surface of the stainless steel.

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