Journal Home > Volume 11 , Issue 7

Polyalkylene glycol (PAG) aqueous solutions have recently been demonstrated to exhibit an ultralow friction coefficient (COF, μ < 0.01). However, the prolonged running-in period and low bearing capacity have limited its widespread application. In this study, we determined that the running-in period can be decreased by more than 75% when the pH value of the lubricant is controlled at 3 by introducing various acid solutions. Additionally, less time was required to realize stable superlubricity with inorganic acid at lower pH values. This was mainly attributed to the acceleration effect of hydrogen ions around the contact region. In case of PAG aqueous solution with organic acid, the wear loss between sliding solid surfaces was reduced, and thus the bearing pressure during the superlubricity period was significantly improved from approximately 30 to 160 MPa. Furthermore, the organic acid molecules were considered to form strong hydrogen bonds with PAG macromolecules and solid surfaces. This in turn strengthened the structure of the adsorption layers. The unique effect of different acids in aqueous polymer lubrication can potentially significantly aid in advancing the study of polymer tribology and broadening industrial applications.


menu
Abstract
Full text
Outline
About this article

Adjustable superlubricity system using polyalkylene glycol with various acid aqueous solutions

Show Author's information Wenrui LIU1Hongdong WANG2( )Yuhong LIU1( )
State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
School of Mechatronic Engineering and Key Laboratory of Advanced Display and System Application, Ministry of Education, Shanghai University, Shanghai 200444, China

Abstract

Polyalkylene glycol (PAG) aqueous solutions have recently been demonstrated to exhibit an ultralow friction coefficient (COF, μ < 0.01). However, the prolonged running-in period and low bearing capacity have limited its widespread application. In this study, we determined that the running-in period can be decreased by more than 75% when the pH value of the lubricant is controlled at 3 by introducing various acid solutions. Additionally, less time was required to realize stable superlubricity with inorganic acid at lower pH values. This was mainly attributed to the acceleration effect of hydrogen ions around the contact region. In case of PAG aqueous solution with organic acid, the wear loss between sliding solid surfaces was reduced, and thus the bearing pressure during the superlubricity period was significantly improved from approximately 30 to 160 MPa. Furthermore, the organic acid molecules were considered to form strong hydrogen bonds with PAG macromolecules and solid surfaces. This in turn strengthened the structure of the adsorption layers. The unique effect of different acids in aqueous polymer lubrication can potentially significantly aid in advancing the study of polymer tribology and broadening industrial applications.

Keywords: superlubricity, hydrogen bond, running-in time, bearing pressure, organic acid

References(42)

[1]
Perry S, Tysoe W. Frontiers of fundamental tribological research. Tribol Lett 19(3): 151–161 (2005)
[2]
Holmberg K, Erdemir A. Influence of tribology on global energy consumption, costs and emissions. Friction 5(3): 263–284 (2017)
[3]
Luo J, Zhou X. Superlubricitive engineering—Future industry nearly getting rid of wear and frictional energy consumption. Friction 8(4): 643–665 (2020)
[4]
Hirano M, Shinjo K. Atomistic locking and friction. Phys Rev B 41: 11837-11851 (1990)
[5]
Meng Y, Xu J, Jin Z, Prakash B, Hu Y. A review of recent advances in tribology. Friction 8(2): 221–300 (2020)
[6]
Shi S, Guo D, Luo J. Micro/atomic-scale vibration induced superlubricity. Friction 9(5): 1163–1174 (2021)
[7]
Zhai W, Zhou K. Nanomaterials in superlubricity. Adv Funct Mater 29(28): 1806395 (2019)
[8]
Song Y, Qu C, Ma M, Zheng Q. Structural superlubricity based on crystalline materials. Small 16(15): 1903018 (2020)
[9]
Chen Xin, Li J. Superlubricity of carbon nanostructures. Carbon 158: 1–23 (2020)
[10]
Wang H, Liu Y. Superlubricity achieved with two-dimensional nano-additives to liquid lubricants. Friction 8(6): 1007–1024 (2020)
[11]
Deng H, Ma M, Song Y, He Q, Zheng Q. Structural superlubricity in graphite flakes assembled under ambient conditions. Nanoscale 10(29): 14314–14320 (2018)
[12]
Berman D, Erdemir A, Sumant A. Approaches for achieving superlubricity in two-dimensional materials. ACS Nano 12(3): 2122–2137 (2018)
[13]
Tan S, Shi H, Fu L, Ma J, Du X, Song J, Liu Y, Zeng Q, Xu H, Wan J. Superlubricity of fullerene derivatives induced by host-guest assembly. ACS Appl Mater. Interfaces 12(16): 18924–18933 (2020)
[14]
Jahn S, Klein J. Hydration lubrication: The macromolecular domain. Macromolecules 48(15): 5059–5075 (2015)
[15]
Ge X, Li J, Luo J. Macroscale superlubricity achieved with various liquid molecules: A review. Front Mech Eng 5: 2 (2019)
[16]
Xiao C, Li J, Chen L, Zhang C, Zhou N, Qing T, Qian L, Zhang J, Luo J. Water-based superlubricity in vacuum. Friction 7(2): 192–198 (2019)
[17]
Yi S, Ge X, Li J. Development and prospects of liquid superlubricity. Journal of Tsinghua University (Science and Technology) 60(8): 617–629 (2020)
[18]
Tomizawa H, Fischer T E. Friction and wear of silicon nitride and silicon carbide in Water: hydrodynamic lubrication at low sliding speed obtained by tribochemical wear. ASLE Trans 30(1): 41–46 (1987)
[19]
Kato K, Adachi K. Wear of Advanced Ceramics. Wear 253(11–12): 1097–1104 (2002)
[20]
Ootani Y, Xu J, Adachi K, Kubo M. First-principles molecular dynamics study of silicon-based ceramics: different tribochemical reaction mechanisms during the running-in period of silicon nitride and silicon carbide. J Phys Chem C 124(37): 20079–20089 (2020)
[21]
Klein J, Kumacheva E, Mahalu D, Perahia D, Fetters L. Reduction of frictional forces between solid surfaces bearing polymer brushes. Nature 370(6491): 634–636 (1994)
[22]
Raviv U, Giasson S, Kampf N, Gohy J F, Jéröme R, Klein J. Lubrication by charged polymers. Nature 425(6954): 163–165 (2003)
[23]
Adibnia V, Olszewski M, De Crescenzo G, Matyjaszewski K, Banquy X. Superlubricity of zwitterionic bottlebrush polymers in the presence of multivalent ions. J Am Chem Soc 142(35): 14843–14847 (2020)
[24]
Nonoyama T, Gong J. Double-network hydrogel and its potential biomedical application: A review. Proc Inst Mech Eng H 229(12): 853–863 (2015)
[25]
Urueña J, Pitenis A, Nixon R, Schulze K, Angelini T, Sawyer W. Mesh size control of polymer fluctuation lubrication in gemini hydrogels. Biotribology 1–2: 24–29 (2015)
[26]
Liu W, Simič R, Liu Y, Spencer N. Effect of contact geometry on the friction of acrylamide hydrogels with different surface structures. Friction 10: 360–373 (2022)
[27]
Li J, Zhang C, Deng M, Luo J. Investigations of the superlubricity of sapphire against ruby under phosphoric acid lubrication. Friction 2(2): 164–172 (2014)
[28]
Han T, Zhang C, Li J, Yuan S, Chen X, Zhang J, Luo J. Origins of superlubricity promoted by hydrated multivalent ions. J Phys Chem Let 11(1): 184–190 (2020)
[29]
Han T, Zhang C, Chen X, Li J, Wang W, Luo J. Contribution of a tribo-induced silica layer to macroscale superlubricity of hydrated ions. J Phys Chem C 123(33): 20270–20277 (2019)
[30]
Arad S, Rapoport L, Moshkovich A, Van Moppes D, Karpasas M, Golan R, Golan Y. Superior biolubricant from a species of red microalga. Langmuir 22(17): 7313–7317 (2006)
[31]
Liu P, Liu Y, Yang Y, Chen Z, Li J, Luo J. Mechanism of biological liquid superlubricity of brasenia schreberi mucilage. Langmuir 30(13): 3811–3816 (2014)
[32]
Zhang L, Liu Y, Chen Z, Liu P. Behavior and mechanism of ultralow friction of basil seed gel. Colloid Surf A 489: 454–460 (2016)
[33]
Wang H, Liu Y, Li J, Luo J. Investigation of superlubricity achieved by polyalkylene glycol aqueous solutions. Adv Mater Interfaces 3(19): 1–9 (2016)
[34]
Ge X, Halmans T, Li J, Luo J. Molecular behaviors in thin film lubrication-part three: superlubricity attained by polar and nonpolar molecules. Friction 7(6): 625–636 (2019)
[35]
Liu W, Wang H, Liu Y, Li J, Erdemir A, Luo J. Mechanism of superlubricity conversion with polyalkylene glycol aqueous solutions. Langmuir 35(36): 11784–11790 (2019)
[36]
Zhang C H, Zhao Y C, Björling M, Wang Y, Luo J, Prakash B. EHL properties of polyalkylene glycols and their aqueous solutions. Tribol Lett 45(3): 379–385 (2012)
[37]
Wang H, Liu Y, Liu W, Liu Y, Wang K, Li J, Ma T, Eryilmaz O, Shi Y, Erdemir A, Luo J. Superlubricity of polyalkylene glycol aqueous solutions enabled by ultrathin layered double hydroxide nanosheets. ACS Appl Mate. Interfaces 11(22): 20249–20256 (2019)
[38]
Liu W, Wang H, Liu Y, Zhang C, Luo J. Controllable superlubricity system of polyalkylene glycol aqueous solutions under various applied conditions. Macromol Mater Eng 305(7): 2000141 (2020)
[39]
Deng M, Zhang C, Li J, Ma L, Luo J. Hydrodynamic effect on the superlubricity of phosphoric acid between ceramic and sapphire. Friction 2(2): 173–181 (2014)
[40]
Li J, Zhang C, Luo J. Superlubricity achieved with mixtures of polyhydroxy alcohols and acids. Langmuir 29(17): 5239–5245 (2013)
[41]
Hartung W, Rossi A, Lee S, Spencer N. Aqueous lubrication of SiC and Si3N4 ceramics aided by a brush-like copolymer additive, poly(l-lysine)-graft-poly(ethylene glycol). Tribol Lett 34: 201–210 (2009)
[42]
Kulig M, Greil P. Surface chemistry and suspension stability of oxide-nitride powder mixtures. J Mater Sci 26: 216–224 (1991)
Publication history
Copyright
Acknowledgements
Rights and permissions

Publication history

Received: 22 February 2021
Revised: 01 July 2021
Accepted: 24 March 2022
Published: 16 July 2022
Issue date: July 2023

Copyright

© The author(s) 2022.

Acknowledgements

This study was financially supported by the National Natural Science Foundation of China (Grant Nos. 51875303 and 51905294) and the Tribology Science Fund of State Key Laboratory of Tribology (Grant No. SKLTKF20A01).

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.

The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.

Return