A study on the tribological characteristics of graphite nano lubricants

Lee, Chang-Gun; Hwang, Yujin; Choi, Youngmin; Lee, Jae-Keun; Choi, Cheol; Oh, Je-Myung

doi:10.1007/s12541-009-0013-4

Cited by 244 publications

(127 citation statements)

References 15 publications

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“…These properties should make them highly desirable for tribological applications. In this work, we demonstrate that crumpled graphene ball is indeed a superior friction modifier compared with other carbon additives such as graphite powders, chemically exfoliated graphene sheets, and carbon black (9)(10)(11)(12)(13)(14)(15)(16). Remarkably, base oil with just 0.01-0.1 wt % of crumpled graphene balls is more effective in friction and wear reduction than a fully formulated commercial lubricant.…”

mentioning

confidence: 71%

Self-dispersed crumpled graphene balls in oil for friction and wear reduction

Dou

Koltonow

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

183

113

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Ultrafine particles are often used as lubricant additives because they are capable of entering tribological contacts to reduce friction and protect surfaces from wear. They tend to be more stable than molecular additives under high thermal and mechanical stresses during rubbing. It is highly desirable for these particles to remain well dispersed in oil without relying on molecular ligands. Borrowing from the analogy that pieces of paper that are crumpled do not readily stick to each other (unlike flat sheets), we expect that ultrafine particles resembling miniaturized crumpled paper balls should selfdisperse in oil and could act like nanoscale ball bearings to reduce friction and wear. Here we report the use of crumpled graphene balls as a high-performance additive that can significantly improve the lubrication properties of polyalphaolefin base oil. The tribological performance of crumpled graphene balls is only weakly dependent on their concentration in oil and readily exceeds that of other carbon additives such as graphite, reduced graphene oxide, and carbon black. Notably, polyalphaolefin base oil with only 0.01-0.1 wt % of crumpled graphene balls outperforms a fully formulated commercial lubricant in terms of friction and wear reduction.

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mentioning

confidence: 71%

Self-dispersed crumpled graphene balls in oil for friction and wear reduction

Dou

Koltonow

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

183

113

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“…Due to minute size of the particles, some other forces of hydrodynamic origin are not included in equation (6). These mainly include the Saffman lift force [13] produced by rotation of the particle caused by the velocity gradient in the viscous layers.…”

Section: Equations Of Motion For the Nanoparticlesmentioning

confidence: 99%

“…Furthermore, using a disc-on-disc tribometer, Lee et al [6] produced Stribeck curves to study the performance of graphite nano-lubricants. They found that the nano-lubricant with 0.5% VF of graphite produced the least coefficient of friction.…”

mentioning

confidence: 99%

Thermohydrodynamics of lubricant flow with carbon nanoparticles in tribological contacts

Shahmohamadi

Rahmani

Rahnejat

et al. 2017

Tribology International

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“…Liu et al [9] and Choi et al [10] are considered copper nanoparticles tribological performance as extracts in grease oil on a tribological stressed wall surface. Lee et al [11] are premeditated the tribological features of graphite nano lubricants. Other nanoparticle with various capping agent, shapes, base liquid, size such as multi-walled carbon nanotubes [12] fullerene nanoparticle [13][14][15] Cu nanoparticle [16] composite nanoparticles [17], Nano-Diamond nanoparticles [18] recommends that the nano-particles dissolved in various lubricant oil presented the starring part in the augmentation of lubrication [19].…”

Section: Introductionmentioning

confidence: 99%

Effects of Nanoparticle Enhanced Lubricant Films in Dynamic Properties of Plain Journal Bearings at High Reynolds Numbers

Jamalabadi

2017

IJET

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Abstract. The aim of this paper is numerical analysis of plain journal bearing with Nano particle added lubricating oil. The fluid film bearing is studied with the modified Reynolds equation which considered time dependent inertia effects at rotating speeds with the linearized turbulence. The research is performed for numerous nano-fluids include nanoparticles of CuO, TiO 2 , Ag and Cu and SAE 20W50 as a base fluid. The time transient governing equations include the incompressible mass conservation equation, Navier-Stokes momentum equations for thin film lubrication, and full kinematic including shaft accelerations are solved numerically. Two cases of long and short bearings are studied with Sommerfeld and Gumbel boundary conditions. Linearized force coefficients such as mass, stiffness and damping factors are obtained for an ordinary journal bearing. The ordinary plain journal bearing velocity response and the rotor displacements when sudden forces applied by rigid rotor symmetrically is achieved. The results prove that using the nanoparticle enhanced lubricant causes higher mass coefficients, damping ratios and fluid effective stiffness.

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A study on the tribological characteristics of graphite nano lubricants

Cited by 244 publications

References 15 publications

Self-dispersed crumpled graphene balls in oil for friction and wear reduction

Self-dispersed crumpled graphene balls in oil for friction and wear reduction

Thermohydrodynamics of lubricant flow with carbon nanoparticles in tribological contacts

Effects of Nanoparticle Enhanced Lubricant Films in Dynamic Properties of Plain Journal Bearings at High Reynolds Numbers

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