Preliminary Study of the Superlubricity Behavior of Polyimide-Induced Liquid Crystal Alignment

Gao, Xiaoya; Chen, Hao; Lv, Sichao; Zhang, Zhiyong; Wang, Tingting

doi:10.1115/1.4051546

Cited by 7 publications

(3 citation statements)

References 33 publications

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“…The formation of this intermediary layer is largely influenced by the molecular structure of the lubricant. A study by Gao et al [ 35 ] demonstrated that certain lubricants, due to their unique molecular structures, could align themselves to form highly ordered ‘liquid crystals’ at the interface, effectively reducing the contact area between the surfaces, and thus enabling superlubricity.…”

Section: Mechanics Of Superlubricitymentioning

confidence: 99%

Superlubricity of Materials: Progress, Potential, and Challenges

et al. 2023

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This review paper provides a comprehensive overview of the phenomenon of superlubricity, its associated material characteristics, and its potential applications. Superlubricity, the state of near-zero friction between two surfaces, presents significant potential for enhancing the efficiency of mechanical systems, thus attracting significant attention in both academic and industrial realms. We explore the atomic/molecular structures that enable this characteristic and discuss notable superlubric materials, including graphite, diamond-like carbon, and advanced engineering composites. The review further elaborates on the methods of achieving superlubricity at both nanoscale and macroscale levels, highlighting the influence of environmental conditions. We also discuss superlubricity’s applications, ranging from mechanical systems to energy conservation and biomedical applications. Despite the promising potential, the realization of superlubricity is laden with challenges. We address these technical difficulties, specifically those related to achieving and maintaining superlubricity, and the issues encountered in scaling up for industrial applications. The paper also underscores the sustainability concerns associated with superlubricity and proposes potential solutions. We conclude with a discussion of the possible future research directions and the impact of technological innovations in this field. This review thus provides a valuable resource for researchers and industry professionals engaged in the development and application of superlubric materials.

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Section: Mechanics Of Superlubricitymentioning

confidence: 99%

Superlubricity of Materials: Progress, Potential, and Challenges

et al. 2023

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“…It is widely recognized that the key to achieving liquid superlubricity is to ensure that the liquid molecules are stabilized on the surface of the friction pair under external pressure while providing very low shear strength [ 34 ]. Through the initial exploration of liquid superlubricity systems, our team also discovered a superlubricity system using nematic liquid crystals (LCs) as the lubricant and GCr15 steel with PI as the friction pair [ 35 , 36 ].…”

Section: Introductionmentioning

confidence: 99%

“…In a previous study, we tested a system with a PI film and GCr15 steel as the friction pair and nematic LCs as the lubricant and found that friction led to the alignment of PI, and aligned PI induced the orientation of LCs in the grooves of PI wear scars, resulting in the stable superlubricity property of the system [ 35 , 36 ]. For this type of superlubricity system, the alignment of PI and LCs is very important.…”

Section: Introductionmentioning

confidence: 99%

Design of Superlubricity System Using Si3N4/Polyimide as the Friction Pair and Nematic Liquid Crystals as the Lubricant

Gao,

Cheng,

Shi

et al. 2023

Polymers

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Polyimide (PI) is a high-performance engineering plastic used as a bearing material. A superlubricity system using Si3N4/PI as the friction pair and nematic liquid crystals (LCs) as the lubricant was designed. The superlubricity performance was studied by simulating the start-stop condition of the machine, and it was found that the superlubricity system had good reproducibility and stability. In the superlubricity system, friction aligned with the PI molecules, and this alignment was less relevant compared to which substance was rubbing on the PI. Oriented PI molecules induced LC molecule alignment when the pretilt angle was very small, and the LC molecules were almost parallel to the PI molecules due to the one-dimensional ordered arrangement of LC molecules and low viscosity, which is conducive to the occurrence of the superlubricity phenomenon.

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Superlubricity by polyimide-induced alignment

et al. 2023

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We have investigated the lubrication alignment behavior of point—plane contact and plane—plane contact between the GCr15 steel and polyimide (PI) friction pair using nematic liquid crystals (LCs) as the lubricant. In this system, rubbing orients the macromolecular PI molecules, and the oriented PI molecules induce alignment of the LC molecules in contact with or close to the oriented PI molecules. The LC molecules are aligned in the wear scar grooves of the PI film, and alignment extends to the GCr15-steel counterpart. Alignment of the LC molecules is correlated with the strong interaction force between the PI and LC molecules, the stable coordination structure of the LCs and GCr15 steel, and the weak interaction between the LC molecules. We performed simulations of the pretilt angle of PI and LCs and discussed the relationship between the pretilt angle and the friction properties. Owing to the small pretilt angle between PI and the LCs, the LC molecules orient almost parallel to the PI material, which is beneficial for superlubricity of this type of friction system.

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Preliminary Study of the Superlubricity Behavior of Polyimide-Induced Liquid Crystal Alignment

Cited by 7 publications

References 33 publications

Superlubricity of Materials: Progress, Potential, and Challenges

Superlubricity of Materials: Progress, Potential, and Challenges

Design of Superlubricity System Using Si3N4/Polyimide as the Friction Pair and Nematic Liquid Crystals as the Lubricant

Superlubricity by polyimide-induced alignment

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