This study presents new Nano-enhanced Phase Change Materials, NePCMs, formulated as dispersions of functionalized graphene nanoplatelets in a poly(ethylene glycol) with mass-average molecular mass 400 g·mol-1 for possible use Thermal Energy Storage. Morphology, functionalization, purity, and thermal stability the nanomaterial and/or were characterized. Design parameters NePCMs defined on basis temporal nanoplatelet using dynamic light scattering. Influence loading solid-liquid phase change...

The rise of the electric vehicles as a more sustainable transport alternative makes it necessary to study new transmission fluids that adapt their needs and improve efficiency. thermophysical properties (contact angle, surface tension rheology) tribological (friction wear) potential PAO8 nanofluids using CaCO3 CeF3 nanoparticles additives are evaluated at mass concentrations 0.05, 0.10, 0.15 0.20 wt%. Low contact angle values obtained, indicating good wettability. When used additives, small...

The search for improved surface properties of engineering alloys is always a matter interest. Herein, we introduce treatment based on depositing non-continuous layer two-dimensional (2D) nanomaterials via simple and scalable method. 2D nanosheets hexagonal boron nitride (h-BN) graphene nanoplatelets (GNP) were sprayed mild steel, followed by heat treatment. are strongly attached to the surfaces even diffused submicron under surface, as proved various analytical techniques. mechanical,...

Thermophysical properties of lubricants are important to understand which ones appropriated for the industrial conditions expected.Thermophysical two different families were analysed: polyalphaolefins (PAO6, PAO20, PAO32 and PAO40) four ester-based lubricants.Specific heat capacity, density, surface tension, contact angle experimentally determined over a broad temperature range through methods such as μDSC, U-tube vibration, drop volume, sessile method, respectively.A clear difference...

This research is based on the investigation of tribological properties a biodegradable polymeric ester lubricant (BIOE) additivated with two different pristine graphene nanoplatelets (GnPs), named as GnP7 and GnP40. These GnPs have lateral sizes 7 40 μm, thickness 3 10 nm, respectively. Four nanoadditive loadings: 0.015, 0.035, 0.055 0.075 wt% been used. Stability nanolubricants has investigated using visual control refractive index evolution during time, revealing slightly better stability...

In this work, two different 2D materials, molybdenum disulfide nanoplatelets (MSNP) and graphene (GNP), prepared by electrochemical exfoliation, were used as additives to prepare nanolubricants. The tribological behaviour of the nanolubricants was evaluated under configurations (pure sliding rolling/sliding) using tribometers: an Universal Macro Materials Tester (UMT-3) a Mini Traction Machine (MTM2). Wear volume determined, after tests, in confocal microscope (Leica DCM 3D) worn surface...

Dispersions based on hexagonal boron nitride, h-BN, nanoparticles, at 0.50, 0.75 and 1.0 wt.% mass concentrations, in an ester base oil composed mainly of trimethylolpropane trioleate, were investigated as potential nanolubricants. The stability the dispersions was assessed to determine reliability tribological, thermophysical rheological measurements. Density viscosity measured from 278.15 373.15 K, while behavior analyzed shear rates 1 1000 s−1 283.15 K. Newtonian exhibited by all...

Recently graphene and other 2D materials were suggested as nano additives to enhance the performance of nanolubricants reducing friction wear-related failures in moving mechanical parts. Nevertheless, our knowledge there are no previous studies on electrochemical exfoliated nanomaterials lubricant additives. In this work, engine oil-based developed via two-steps method using two different nanomaterials: a carbon-based additive, nanoplatelets (GNP) sulphide nanomaterial, molybdenum disulfide...

Lubricant properties of trimethylolpropane trioleate synthetic base oil (TMPTO) were experimentally determined under different temperatures, pressures and rolling-sliding conditions. With the aim to obtain viscosity-pressure coefficient, density viscosity measurements performed up 150 MPa with a falling-body viscometer vibrating tube densimeter, respectively. Film thickness friction ball-on-disc apparatus from temperatures 303.15 353.15 K, slide-roll ratios 5 50% at 50 N (applied load)....

This work is focused on the thermophysical and tribological study of eight nanolubricant compositions based a polyalphaolefin (PAO 20) two different nanoadditives: multi-walled carbon nanotubes (MWCNTs) hexagonal boron nitride (h-BN). Regarding properties, density dynamic viscosity base oil nanolubricants were measured in range 278.15-373.15 K, as well their index, with aim evaluating variation these properties addition nanoadditives. On other hand, lubricant such contact angle, coefficient...

This article presents 2D mica nanoplatelets as a novel additive to produce stable engine lubricant. The planar structure and excellent mechanical properties of contribute significantly the improvements in tribological performance when evaluated under pure sliding rolling/sliding contact configurations. wear rate is reduced by 72 %, coefficient friction (COF) decreases 28 % added oil conditions. No improvement was observed Our results also showed that nanosheet loading plays significant role...

Abstract In this study, the improvement in SAE 10W-40 engine oil tribological performance after addition of magnesium oxide (MgO) nanoadditive and two different phosphonium-based ionic liquids (ILs) was investigated. Besides, rheological behaviour MgO-based nanolubricant IL-based hybrid nanolubricants at temperature range from 293.15 to 363.15 K studied. The nanoparticle characterization performed by means transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy...

In the present work, lubrication properties (friction and wear) of a synthetic ester oil, tris(2-ethylhexyl) trimellitate (TOTM) containing ferrite nanoparticles coated with oleic acid (F3O4-OA) were investigated for two different material pairs: steel ball-steel disc silicon nitride disc. Thus, four TOTM nanolubricants formulated: + 0.010 wt% Fe3O4-OA, 0.015 0.020 Fe3O4-OA 0.025 showing all them moderate time stability due to coating. Wettability behaviour ferrite-based on surface was...

In this work, the thermophysical properties of four mineral (paraffinic and naphthenic) synthetic (polyalphaolefin ester) base oils are measured. Knowledge these is vital importance for correct optimal formulation design lubricants, development equations state transport models that adequately represent their properties. Density, isothermal compressibility, thermal expansion coefficient, dynamic viscosity, pressure–viscosity contact angle were determined. To carry out a pρT apparatus,...

Two new highly viscous biodegradable oils are investigated for use in wind turbine gearboxes (BIO-G00) and mechanical transmissions of agricultural tractors (BIO-G02). Studies on their thermophysical tribological properties were performed. High-pressure–viscosity measurements obtained up to 250 MPa 363.15 K using a falling-body apparatus. The viscosity BIO-G00 BIO-G02 reaches maximum values 14720 7072 mPa·s, respectively. film thickness the performance, from boundary full-fluid lubrication...

Characterization of elastohydrodynamic lubrication, EHL, contacts requires an appropriate EoS for the lubricant. Experimental viscosities and speeds sound six lubricants from 278.15 to 398.15 K at 0.1 MPa together with densities up 120 are reported. Tammann-Tait two EoSs based on scaling concept describe experimental oils average deviations lower 0.03%. Dowson-Higginson Zhu Wen equations currently used in numerical simulations EHL regime predict these AADs than 0.5%. The prediction ability...

Abstract Chemical exfoliation is an attractive approach for the synthesis of graphene due to its low cost and simplicity. However, challenges still remain in characterization solution-processed graphene, particular with atomic resolution. Through this work we demonstrate x-ray pair distribution function as a novel study or other 2D materials resolution, directly solution, produced by liquid-phase electrochemical exfoliations. The results show disappearance long-range correlations, both...

Electric vehicles (EVs) have emerged as a technology that can replace internal combustion and reduce greenhouse gas emissions. Therefore, it is necessary to develop novel low-viscosity lubricants serve potential transmission fluids for electric vehicles. Thus, this work analyzes the influence of both SiO2 SiO2-SA (coated with stearic acid) nanomaterials on tribological behavior paraffinic base oil an ISO VG viscosity grade 32 133 index. A traditional two-step process through ultrasonic...

Abstract This article explores the potential of cellulose nanocrystals (CNCs) as a lubricant additive for isopropyl palmitate (IPP) oil to enhance its tribological performance. CNCs, derived from renewable sources, offer sustainable and environmentally friendly alternative traditional additives. A two-step method was used prepare nanolubricants, with visual control dynamic light scattering measurements assess their temporal stability. The viscous behavior in terms viscosity index, evaluated...