Tribological behavior of nano TiO2 as an additive in base oil

The structure and friction of fatty acid surfactant films adsorbed on iron oxide surfaces lubricated by squalane are examined using large-scale molecular dynamics simulations. The structures of stearic acid and oleic acid films under static and shear conditions, and at various surface coverages, are described in detail, and the effects of unsaturation in the tail group are highlighted. At high surface coverage, the measured properties of stearic acid and oleic acid films are seen to be very similar. At low and intermediate surface coverages, the presence of a double bond, as in oleic acid, is seen to give rise to less penetration of lubricant in to the surfactant film and less layering of the lubricant near to the film. The kinetic friction coefficient is measured as a function of shear rate within the hydrodynamic (high shear rate) lubrication regime. Lubricant penetration and layering are observed to be correlated with friction coefficient. The friction coefficient with oleic acid depends only weakly on...

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Structure and friction of stearic acid and oleic acid films adsorbed on iron oxide surfaces in squalane.

To improve the oil-solubility of nanoparticles, a new technology was used to prepare a kind of lubricant containing titanium dioxide (TiO2) nanoparticles. The microstructures of the prepared nanoparticles were characterized via transmission electron microscope (TEM) and infrared spectroscopy (IR). Tribological properties of TiO2 nanoparticles used as an additive in base oil were evaluated using four-ball tribometer and ball-on-disk tribometer. In addition, the worn surface of the steel ball was investigated via polarized microscopy (PM) and X-ray photoelectron spectroscopy (XPS). The TiO2 nanoparticles can be completely well-dispersed in the base oil under a new process (NP), which has no significantly negative effect on the anti-oxidation property. The results of the tribological tests show that TiO2 nanoparticles under the NP show a better anti-wear property and friction-reducing property in base oil compared to TiO2 nanoparticles under the tradition process (TP). The main aim of this paper lies in solving with the oil-solubility problem through the combination effect of surface modification and special blend process of lubricating oil. This method was first used to prepare lubricant containing TiO2 nanoparticles and then used as additives in engine oil, gear oil, and other industrial lubricants. At the same time, tribological properties of TiO2 nanoparticles in base oil as a lubricating additive were also studied.

https://www.mdpi.com/2075-4442/4/2/12/pdf

Tribological Properties of the Lubricant Containing Titanium Dioxide Nanoparticles as an Additive

Titanium dioxide nanoparticles (TiO2) were synthesized and then dual-coated with silane coupling agent (KH-570) and OP- 10 in sequence in order to be dispersed stably in water as lubricant additives. The tribological properties and the application performance in Q235 steel machining of the nanoparticles aswater-based lubricant additives were investigated on an MSR-10D fourball tribotester and on a bench drilling machine, respectively. Scanning electron microscope (SEM) and atomic force microscope (AFM) were used to analyze the worn surface. The results show that the surface-modified TiO2 nanoparticles can remarkably improve the load-carrying capacity, the friction reducing, and anti wear abilities of pure water. The wear scar diameter and the coefficient of friction of the water-based lubricating fluids with TiO2 nanoparticles decreased, and the thick deep furrows on the surface of wear scar also decreased obviously with the increase of TiO2 concentration. The power consumption in drilling process was lower and the cutting surface was smoother using the water-based lubricating fluids added TiO2 nanoparticles compared to the fluid without addition. The reason for nanoparticles improving tribological properties of water based lubricating fluid might be the formation of a dynamic deposition film during rubbing process according to analysis of the worn surface.

/pdf/preparation-and-tribological-properties-of-dual-coated-tio-2-1zff6dlkwz.pdf

Preparation and tribological properties of dual-coated TiO 2 nanoparticles as water-based lubricant additives

Tribological characteristics of monodispersed cerium borate nanospheres in biodegradable rapeseed oil lubricant

Preparation and tribological properties of stearic acid-modified hierarchical anatase TiO2 microcrystals

In-situ synthesis of CNT/TiO2 heterojunction nanocomposite and its efficient photocatalytic degradation of Rhodamine B dye

The defect is perfect: MoS2/TiO2 modified with unsaturated Mo vacancies to construct Z-scheme heterojunction & improve mobility of e-

Oxidation behavior of the Ti38V15Nb23Hf24 refractory high-entropy alloy at elevated temperatures

TiO2 can be integrated with antimony-doped tin oxide to obtain composite materials with high electroconductivity. Based on this, spherical TiO2@Sb–SnO2 (TSS) has been prepared by homogeneous precipitation combined with a high-temperature calcination process. The morphology, structure and composition of TSS were characterized by scanning electron microscope, Brunauer–Emmet–Teller surface area analyzer, X-ray diffractometer and transmission electron microscope with energy-dispersive X-ray spectrometer, respectively. Effects of dropping conditions, introducing sulfate, pH value, calcination temperature and holding time on the conductivity of TSS were investigated by measuring resistivity, Zeta potential and particle size, meanwhile the calcination action and conductive mechanism by thermogravimetric analysis, X-ray photoelectron spectroscopy and electron spin resonance. The results revealed that the core–shell structured TSS was formed, and the resistivity of composite powder was below 4.0 Ω cm under the optimum conditions. Our analysis indicates that the conductive channel mechanism is the main conductive mechanism of the as-prepared composite.

Lin Liu

Papers

Preparation and tribological properties of stearic acid-modified hierarchical anatase TiO2 microcrystals

In-situ synthesis of CNT/TiO2 heterojunction nanocomposite and its efficient photocatalytic degradation of Rhodamine B dye

The defect is perfect: MoS2/TiO2 modified with unsaturated Mo vacancies to construct Z-scheme heterojunction & improve mobility of e-

Oxidation behavior of the Ti38V15Nb23Hf24 refractory high-entropy alloy at elevated temperatures

Fabrication of core–shell structured TiO2@Sb–SnO2 with improved electroconductivity