Single Wall Carbon Nanohorns (SWCNHs) are tiny graphene sheets, wrapped to form horn-shaped cones with a half fullerene cap, having 30-50 nm length and 2-5 nm diameter, typically coalescing in dahlia like aggregates of about 100 nm. Nanofluids, i.e. dispersion of nanoparticles in conventional fluids, are studied in several application fields for their enhanced attributes, i.e. heat transfer or lubricant properties. Recently, SWCNHs were used to prepare nanofluids and the present work concerns the preparation of a stable dispersion of SWCNHs in lubricant oils and the measurement of the improvements of the tribological properties showed by such a new nanolubricant. The improvement of lubrication is of paramount importance for reduction of fuel and oil consumption, increasing of output power, reduction of harmful emissions, increasing of durability, reliability and life of engines. Addition of nanoparticles in lubricating oils seems effective on reducing the coefficient of friction and increasing the load-carrying capability of lubricant in mechanical couplings. Dynamic Light Scattering (DLS) and viscosity characterizations were performed to evaluate the stability in time of the nanolubricant and the effect of SWCNHs on physical properties of the bare oil. Stribeck tests were used to evaluate the tribological performances and to highlight transitions between different lubrication regimes. Wear tests were also carried out in order to confirm the results obtained by Stribeck characterization, and to evaluate the effects of dispersed SWCNH on friction and anti-wear properties of the nanolubricant. All tests were performed at temperatures ranging from 25° to 80°C with a tribotester with a ball-on-disk configuration. This new nanolubricant revealed to be a promising candidate to develop a new class of composite lubricants, suitable and effective in different operating environments. Due to SWCNHs addition, a general improvement of raw oil tribological properties for each operating temperature was observed, with a reduction of over 10% in friction coefficient and a wear rate decreased between 20% and 30%.
Addition of single wall carbon nanohorns to improve the tribological properties of lubricant oils
V Zin;L Colla;F Agresti;S Barison
2013
Abstract
Single Wall Carbon Nanohorns (SWCNHs) are tiny graphene sheets, wrapped to form horn-shaped cones with a half fullerene cap, having 30-50 nm length and 2-5 nm diameter, typically coalescing in dahlia like aggregates of about 100 nm. Nanofluids, i.e. dispersion of nanoparticles in conventional fluids, are studied in several application fields for their enhanced attributes, i.e. heat transfer or lubricant properties. Recently, SWCNHs were used to prepare nanofluids and the present work concerns the preparation of a stable dispersion of SWCNHs in lubricant oils and the measurement of the improvements of the tribological properties showed by such a new nanolubricant. The improvement of lubrication is of paramount importance for reduction of fuel and oil consumption, increasing of output power, reduction of harmful emissions, increasing of durability, reliability and life of engines. Addition of nanoparticles in lubricating oils seems effective on reducing the coefficient of friction and increasing the load-carrying capability of lubricant in mechanical couplings. Dynamic Light Scattering (DLS) and viscosity characterizations were performed to evaluate the stability in time of the nanolubricant and the effect of SWCNHs on physical properties of the bare oil. Stribeck tests were used to evaluate the tribological performances and to highlight transitions between different lubrication regimes. Wear tests were also carried out in order to confirm the results obtained by Stribeck characterization, and to evaluate the effects of dispersed SWCNH on friction and anti-wear properties of the nanolubricant. All tests were performed at temperatures ranging from 25° to 80°C with a tribotester with a ball-on-disk configuration. This new nanolubricant revealed to be a promising candidate to develop a new class of composite lubricants, suitable and effective in different operating environments. Due to SWCNHs addition, a general improvement of raw oil tribological properties for each operating temperature was observed, with a reduction of over 10% in friction coefficient and a wear rate decreased between 20% and 30%.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
