Effects of Surface Roughness in Squeeze Film Lubrication of Spherical Bearings

Kumar, Jai; Rao, R. Raghavendra

doi:10.1016/j.proeng.2015.11.442

Cited by 7 publications

(7 citation statements)

References 10 publications

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“…The slight increment of dispersive component is associated with the physical interaction between testing fluids and the fault surface that consists of asperities or defects like cracks or pores. The cavities on UHMWPE/1.0GO's surface could be enhanced dispersion forces resulting from correlated movements of the electrons on the sample surface, which allow the fluids to have a relatively higher affinity of spreading 63,64 . Meanwhile, it has been recognized that hydrogen bonds can be formed between amino groups and carboxyl groups in protein molecules, allowing the adsorption of proteins to solid surfaces.…”

Section: Resultsmentioning

confidence: 99%

“…surface, which allow the fluids to have a relatively higher affinity of spreading. 63,64 Meanwhile, it has been recognized that hydrogen bonds can be formed between amino groups and carboxyl groups in protein molecules, allowing the adsorption of proteins to solid surfaces. Therefore, we believe that the UHMWPE/1.0GO has a higher protein adsorption capacity than other composite samples, even though it showed the least hydrophobicity.…”

Section: Surface Roughnessmentioning

confidence: 99%

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Effects of surface wettability and thermal conductivity on the wear performance of ultrahigh molecular weight polyethylene/graphite and ultrahigh molecular weight polyethylene/graphene oxide composites

Shahemi

Liza

Sawae

et al. 2022

Polymers for Advanced Techs

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Recent studies have found a rapid increase of ultrahigh molecular weight polyethylene (UHMWPE) wear in the presence of proteins from the synovial fluid. Due to UHMWPE's high hydrophobicity, it tends to adsorb a tremendous amount of proteins. Moreover, since UHMWPE has low thermal conductivity, a temperature rise in the center of the contact area due to frictional heating could cause protein denaturation from the synovial fluid. It has been shown that the denatured protein may increase the adhesive wear response. This study aimed to address the effects of graphite and graphene oxide (GO) addition on the wear properties of UHMWPE in protein environments. The surface properties were characterized using surface roughness profiler, surface energy evaluation, zeta potential, and Fourier transform infra-red (FTIR). Following that, wear properties of UHMWPE composite were evaluated using a multidirectional pin-on-disc wear test under a bovine serum lubricated condition. The worn surface of the UHMWPE composite sample was evaluated, and the dominating factors of wear properties were determined. The effect of protein adsorption on the composite surface was also assessed after the wear test. The hydrophilicity of UHWMPE/1.0GO is considered to be the dominant contribution determining protein adsorption in static conditions. UHMWPE composite's wear resistance improvement was primarily dominated by GO filler (1.0 wt%) near the sliding surface, which has improved the subsurface strength of the material and heat dissipation effect, which reduces the denaturation of the proteins.

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Section: Resultsmentioning

confidence: 99%

Section: Surface Roughnessmentioning

confidence: 99%

Effects of surface wettability and thermal conductivity on the wear performance of ultrahigh molecular weight polyethylene/graphite and ultrahigh molecular weight polyethylene/graphene oxide composites

Shahemi

Liza

Sawae

et al. 2022

Polymers for Advanced Techs

View full text Add to dashboard Cite

show abstract

“…Followed by UHMWPE/GO and UHMWPE showed the lowest wettability. The wettability of the sample was likely to be elevated by surface chemical composition on the surface or/and the physical interaction between the FBS and solid surface morphology [28][29]. However, the interactions of the bovine serum with the surface can't be specifically determined by comparing the magnitude of the contact angle alone.…”

Section: Wettabilitymentioning

confidence: 99%

“…This indicated that the physical interaction between the testing fluids is mainly contributed to the hydrophobicity reduction of the UHMWPE composites as opposed to their surface chemistry. The physical interaction between the testing fluids and the surface morphology of the samples was likely to be encouraged due to the existence of temporary electrons on the sample surface [28][29], which allow the fluids to have a relatively Fig. 2.…”

Section: Wettabilitymentioning

confidence: 99%

Effect of Protein Interactions on the UHMWPE Composites After the Multidirectional Wear Test

Shahemi

Liza

Sawae

et al. 2021

Preprint

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Recent studies have found a rapid increase of ultrahigh molecular weight polyethylene (UHMWPE) wear in the presence of proteins from the synovial fluid. This is due to the high hydrophobicity surface of UHMWPE which allows the proteins to get interacted and adsorbed to the UHMWPE surface. Moreover, since UHMWPE has low thermal conductivity, the heat elevated produced from the articulating contact surfaces would be slowly dissipated and protein structure becoming denatured. The denatured proteins were claimed could increase the adhesive wear response. Thus, the main objective of this study is to evaluate the influence of the graphene oxide (GO) and graphite flake (GF) on the UHMWPE’s heat dissipation and wettability characteristics in regards to reducing the protein denaturation effect on the surface. The surface properties were characterized by using surface energy evaluation, zeta potential, and Fourier Transform Infra-red (FTIR). Following that, wear properties of each UHMWPE composite were evaluated by using a multidirectional pin-on-disc wear test under a lubricated condition. The worn surface of each pin sample was evaluated, and the dominating factors of wear properties were determined. In addition to that, the effect of protein absorption on the UHMWPE composites was also evaluated in this study. The results show both fillers (GO and GF) had no effect in altering the UHMWPE composites’ physicochemical properties. The improvement of UHMWPE composite’s wear properties was discovered to be primarily dominated by the existence of GO filler (1.0 wt%) near the sliding surface has improved the subsurface strength of the material and heat dissipation effect which reduces the denaturation of the proteins.

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“…In the year 1962, Dowson [6] unified the various attempts in generalizing the Reynolds Equation by considering the variation of fluid properties across as well as along the fluid film thickness by neglecting the slip effects at the bearing surfaces. Since then many researchers have studied the effects of viscosity variation in lubricated systems by considering Reynolds Equation [7][8][9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Effect of Cartilage Porosity on Synovial Joint: Boosted Lubrication

Shekhar¹,

Tyagi²

2019

IJRAT

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An analytical solution of load bearing characteristics in a squeeze film model for normal human knee joint is obtained. The cartilage surfaces are taken to be porous and the viscosity variation of synovial fluid with hyaluronate concentration is also considered. It is found that the effect of permeability in the normal direction has a favorable effect on the load capacity as well as on the squeeze time.

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Effects of Surface Roughness in Squeeze Film Lubrication of Spherical Bearings

Cited by 7 publications

References 10 publications

Effects of surface wettability and thermal conductivity on the wear performance of ultrahigh molecular weight polyethylene/graphite and ultrahigh molecular weight polyethylene/graphene oxide composites

Effects of surface wettability and thermal conductivity on the wear performance of ultrahigh molecular weight polyethylene/graphite and ultrahigh molecular weight polyethylene/graphene oxide composites

Effect of Protein Interactions on the UHMWPE Composites After the Multidirectional Wear Test

Effect of Cartilage Porosity on Synovial Joint: Boosted Lubrication

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