The Effect of Geometrical Shape of Surface Texture on the Rheology and Tribology of Confined Lubricants

Understanding lubrication at the nanoscale is essential for reducing friction. While alkanes, the primary component in most lubricants, have been studied for their molecular structure’s impact on rheology and behavior when confined by solid surfaces, the influence of confining surface texture remain...

Full description

Saved in:
Bibliographic Details
Main Authors: Fankai Peng, Ahmad Jabbarzadeh
Format: Article
Language:English
Published: MDPI AG 2025-01-01
Series:Lubricants
Subjects:
Online Access:https://www.mdpi.com/2075-4442/13/1/13
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832588044446728192
author Fankai Peng
Ahmad Jabbarzadeh
author_facet Fankai Peng
Ahmad Jabbarzadeh
author_sort Fankai Peng
collection DOAJ
description Understanding lubrication at the nanoscale is essential for reducing friction. While alkanes, the primary component in most lubricants, have been studied for their molecular structure’s impact on rheology and behavior when confined by solid surfaces, the influence of confining surface texture remains underexplored. This research uses molecular dynamics simulations to investigate the rheological behavior of thin film lubrication between various patterned rough surfaces. The study focuses on sinusoidal, sawtooth, and squaretooth wave-patterned surfaces, using hexadecane as the lubricant. The simulations examine the effects under different normal loads and shear rates. Surface patterns significantly influence the formation and structure of crystalline bridges, depending on shear rates and normal loads. The sawtooth wave-patterned surface exhibits the highest viscosity under low normal load and shear rate conditions, forming crystalline bridges with a molecular orientation perpendicular to the shear direction. The squaretooth patterns exhibit the lowest viscosities due to the nematic order in crystalline bridges with molecules aligned in the shearing direction. The sinusoidal wave-patterned surface shows intermediary viscosity with disordered crystalline bridge groups formed with random molecular orientation. The lowest viscosity provided by the squaretooth pattern surface persists across various conditions, including both transitory and steady states, under high and low loads, and over a wide range of shear rates. However, the difference in shear viscosity is reduced at higher normal loads. This research provides valuable insights for designing nanoelectromechanical systems (NEMS) and other applications where boundary conditions are critical to lubrication.
format Article
id doaj-art-2173b45ad0294cc8bfb82c1b13fdaa9e
institution Kabale University
issn 2075-4442
language English
publishDate 2025-01-01
publisher MDPI AG
record_format Article
series Lubricants
spelling doaj-art-2173b45ad0294cc8bfb82c1b13fdaa9e2025-01-24T13:38:58ZengMDPI AGLubricants2075-44422025-01-011311310.3390/lubricants13010013The Effect of Geometrical Shape of Surface Texture on the Rheology and Tribology of Confined LubricantsFankai Peng0Ahmad Jabbarzadeh1School of Aerospace, Mechanical, and Mechatronic Engineering, University of Sydney, Camperdown, NSW 2006, AustraliaSchool of Aerospace, Mechanical, and Mechatronic Engineering, University of Sydney, Camperdown, NSW 2006, AustraliaUnderstanding lubrication at the nanoscale is essential for reducing friction. While alkanes, the primary component in most lubricants, have been studied for their molecular structure’s impact on rheology and behavior when confined by solid surfaces, the influence of confining surface texture remains underexplored. This research uses molecular dynamics simulations to investigate the rheological behavior of thin film lubrication between various patterned rough surfaces. The study focuses on sinusoidal, sawtooth, and squaretooth wave-patterned surfaces, using hexadecane as the lubricant. The simulations examine the effects under different normal loads and shear rates. Surface patterns significantly influence the formation and structure of crystalline bridges, depending on shear rates and normal loads. The sawtooth wave-patterned surface exhibits the highest viscosity under low normal load and shear rate conditions, forming crystalline bridges with a molecular orientation perpendicular to the shear direction. The squaretooth patterns exhibit the lowest viscosities due to the nematic order in crystalline bridges with molecules aligned in the shearing direction. The sinusoidal wave-patterned surface shows intermediary viscosity with disordered crystalline bridge groups formed with random molecular orientation. The lowest viscosity provided by the squaretooth pattern surface persists across various conditions, including both transitory and steady states, under high and low loads, and over a wide range of shear rates. However, the difference in shear viscosity is reduced at higher normal loads. This research provides valuable insights for designing nanoelectromechanical systems (NEMS) and other applications where boundary conditions are critical to lubrication.https://www.mdpi.com/2075-4442/13/1/13crystalline bridgehexadecanemolecular dynamicspatterned wallrheology behaviorrough surface
spellingShingle Fankai Peng
Ahmad Jabbarzadeh
The Effect of Geometrical Shape of Surface Texture on the Rheology and Tribology of Confined Lubricants
Lubricants
crystalline bridge
hexadecane
molecular dynamics
patterned wall
rheology behavior
rough surface
title The Effect of Geometrical Shape of Surface Texture on the Rheology and Tribology of Confined Lubricants
title_full The Effect of Geometrical Shape of Surface Texture on the Rheology and Tribology of Confined Lubricants
title_fullStr The Effect of Geometrical Shape of Surface Texture on the Rheology and Tribology of Confined Lubricants
title_full_unstemmed The Effect of Geometrical Shape of Surface Texture on the Rheology and Tribology of Confined Lubricants
title_short The Effect of Geometrical Shape of Surface Texture on the Rheology and Tribology of Confined Lubricants
title_sort effect of geometrical shape of surface texture on the rheology and tribology of confined lubricants
topic crystalline bridge
hexadecane
molecular dynamics
patterned wall
rheology behavior
rough surface
url https://www.mdpi.com/2075-4442/13/1/13
work_keys_str_mv AT fankaipeng theeffectofgeometricalshapeofsurfacetextureontherheologyandtribologyofconfinedlubricants
AT ahmadjabbarzadeh theeffectofgeometricalshapeofsurfacetextureontherheologyandtribologyofconfinedlubricants
AT fankaipeng effectofgeometricalshapeofsurfacetextureontherheologyandtribologyofconfinedlubricants
AT ahmadjabbarzadeh effectofgeometricalshapeofsurfacetextureontherheologyandtribologyofconfinedlubricants