Pulsed Laser Manufactured Heteroatom Doped Carbon Dots via Heterocyclic Aromatic Hydrocarbons for Improved Tribology Performance

Small, Journal Year: 2024, Volume and Issue: 20(29)

Published: Feb. 25, 2024

Traditional laser-assisted method (top-down synthesis strategy) is applied in the preparation of carbon dots (CDs) by cutting larger materials, which requires harsh conditions, and size distribution CDs seldom monodisperse. In this work, heteroatom-doped CDs, represented N,S co-doped (N,S-CDs), can be prepared successfully pulsed laser irradiation heterocyclic aromatic hydrocarbons-based small molecule compound solution. The friction coefficient (COF) base oil PAO decreases from 0.650 to 0.093, wear volume reduces 92.0% accompanied 1 wt.% N,S-CDs addition, while load-bearing capacity improved 100 950 N. excellent lubrication performance mainly attributed formation a robust tribofilm via tribochemical reaction between pairs, play mending effect polishing for worn surfaces. Furthermore, lubricant containing heteroatom doped are capable being situ hydrocarbons oil, avoid redispersed problem nano-additive maintain long-term dispersion, with COF 0.103 low ≈1.99 × 10

Language: Английский

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Carbon Dots with Spatially‐Mediated‐N/S‐Co‐Doping Enabling One‐Year Stable Lubricant with Oil Leakage Detection Capability

Small, Journal Year: 2024, Volume and Issue: 20(29)

Published: Feb. 17, 2024

Abstract The dispersion stability of nano‐lubricating additives is crucial for the shelf life lubricant and its practical applications. Nitrogen–sulfur co‐doped carbon dots (N,S@CDs) via a one‐step hydrothermal method with nitropyrene thiourea as raw materials are hereby presented. N S elements selectively distributed throughout entire skeleton doping amount 22.6 at%. as‐synthesized N,S@CDs exhibit excellent in PEG200 maintain over one year. experiment results indicate that significantly improve anti‐wear friction reduction properties PEG200, while coefficient reduced from 0.25 to 0.09 1.5 wt% addition, wear volume, depth, width by 68%, 52%, 57%, respectively. good lubrication performance attributed stability, enhanced filling polishing effects, complex tribochemical reactions caused heteroatom form stable protective film on worn surface. Furthermore, as‐prepared intrinsic fluorescence intensity photoluminescence quantum yield (PLQY) 12.5% remain fluorescent during long‐term process, therefore have potential application prospect non‐destructive detection oil leakage labeling method.

Language: Английский

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Tribological properties of graphene quantum dot hybrid polyethylene glycol lubricated molybdenum disulfide films

Tribology International, Journal Year: 2024, Volume and Issue: 193, P. 109437 - 109437

Published: Feb. 17, 2024

Language: Английский

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Macroscale Superlubricity with High Pressure Enabled by Partially Oxidized Violet Phosphorus for Engineering Steel

Advanced Functional Materials, Journal Year: 2024, Volume and Issue: 34(36)

Published: May 9, 2024

Abstract As a novel cross‐structured 2D material, violet phosphorus (VP) promises to further develop the dynamic performance, energy efficiency, and service lifetime of mechanical components owing its high strength toughness, large carrier mobility, wide bandgap, good friction‐reducing properties. In this work, partially oxidized nanosheets (oVP) are synthesized employed as lubricating additives in poly alpha olefin (PAO) oil environment with less oleic acid (OA) improver, which can trigger macroscale superlubricity on diamond‐like carbon (DLC) film deposited steel surface at loading pressures (>800 MPa) sliding speeds (>0.1 m s −1 ). The friction coefficient (COF) steel‐DLC tribopair lubricated by oVP‐PAO reduce down 0.0064 little wear. At high‐pressure interface, force‐thermal coupling action during running‐in process promotes cleavage recombination oVP OA molecules form reliable chemical adsorption tribofilm mainly composed oxides amorphous carbon, prevents original asperities from direct contact provides an ultralow shear strength. These findings suggest new method achieve oil‐based for engineering through lubrication catalyzation effects oVP.

Language: Английский

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Robust and durable superlubricity enabled by carboxylated graphene quantum dots in lubricated steel contacts

Carbon, Journal Year: 2024, Volume and Issue: 226, P. 119226 - 119226

Published: May 9, 2024

Achieving macroscale superlubricity on engineering steel by utilizing aqueous green lubricants has gained growing interest, given its substantial potential to reduce energy consumption and carbon footprint. However, maintaining under diverse sliding conditions over a prolonged duration is major obstacle for real-scale applications. Herein, we report that robust durable tribofilm enabled unique lubrication mechanism based carboxylated graphene quantum dots (CGQDs) in glycerol triggers self-mated contacts. A dedicated intermittent test was designed show the superlubricity's robustness ability of adapt variety relevant conditions. Moreover, boundary film provides an average coefficient friction around 0.007 up 69 % wear reduction (compared base lubricant), resulting maintenance at real final contact pressure 123 MPa, which increases upper limit compared current aqueous-lubricated The new chemical adsorption CGQDs onto worn metal surface, coupled with tribo-induced structural degradation transformation into layered graphitic structures generate adaptable low-shear interface. This work insights role achieving important step forward implementing energy-efficient technologies industrial

Language: Английский

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Preparation of near superlubric polysiloxane/Ti3C2Tx nanocomposite coating by incorporating polyalphaolefin oil microcapsules

Tribology International, Journal Year: 2025, Volume and Issue: unknown, P. 110555 - 110555

Published: Jan. 1, 2025

Language: Английский

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Liquid-Like Carbon Dots as Lubricating Grease Additives

ACS Applied Nano Materials, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 29, 2025

Liquid-like nanomaterials are emerging as unique nanolubricating materials due to their combined advantages of fluidity and nanoscale size. However, development application have been hindered by relatively complex synthesis processes. Herein, a one-step method for synthesizing liquid-like carbon dots (LCDs) was developed introducing ammonium salts into citric acid–based system. Compared solid (CDs) synthesized with acid, LCDs exhibit characteristics, which were further explored through molecular simulations. When used additives in lubricating grease, demonstrate excellent tribological performance, including friction reduction, antiwear properties, improved load-carrying capacity. This study not only introduces simple cost-effective strategy producing LCDs, advancing the CDs but also expands understanding grease.

Language: Английский

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Dynamic Covalent Oleogel with Mechanical Force‐Induced Reversible Phase Transition for Self‐Adaptive Lubrication

Advanced Functional Materials, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 9, 2025

Abstract Substantial progress has been made in stimulus‐responsive and performance‐tunable hydrogels, yet endowing organogels with dynamic adaptive properties remains challenging. Especially, the development of functional oleogel materials is further constrained by weak interactions between oil gel network, along high viscosity oil. Herein, state self‐adaptability oleogels enabled constructing mechanical responsive covalent networks via ring‐opening polymerization thioctic acid (TA). Mechanically breaking rebuilding disulfide bonds endow force‐induced reversible phase transition poly(TA) oleogels. Mechanical bond breakage disrupts transforming into a sol state. Once force removed, rapid bonding sulfur radicals rebuilds network. Furthermore, this highly generalizable strategy potential as self‐adaptive lubricant. Self‐adaptive can exist or that adapts to whether machine running stopped. Systematic tribological tests confirm excellent lubricating their outstanding performance stability adapting changing friction conditions. This provides insights for developing properties, well new smart materials.

Language: Английский

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Synthesizing lignin-based gelators to prepare oleogels used as green and fossil-free greases

International Journal of Biological Macromolecules, Journal Year: 2025, Volume and Issue: 305, P. 141074 - 141074

Published: Feb. 19, 2025

Traditional lubricating greases are mainly derived from petroleum, which poses major environmental challenges due to their non-biodegradability and pollution issues. This study attempts synthesize lignin-based green thickeners explore potential for developing fossil-free greases. A gelator was successfully synthesized by reacting malic acid with lignin epoxidized soybean oil, in participated both the esterification reaction ring-opening of epoxy group. used as thickener prepare several different oils, e.g., castor rapeseed PAO 15, paraffin oil. It found that combining this oil can be preparing greases, while it does not work other oils. Rheological studied showed 35 % gelator-castor grease exhibited strong gel-like behaviour, storage modulus (G', 400 Pa) exceeding loss (G", 40 shear-thinning viscosity reducing 106 104 mPa·s under stress. Comprehensive tribological studies on developed show gelators significantly improve lubricant performance (about 20 lower friction around wear a contact pressure 2.72 GPa, reciprocating speed 0.1 m/s, 80 °C). XPS analysis further revealed ability form protective film metal surfaces. demonstrates great provides new ideas high-performance, green,

Language: Английский

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Superlubricity Microcapsules

ACS Applied Materials & Interfaces, Journal Year: 2025, Volume and Issue: 17(9), P. 14634 - 14644

Published: Feb. 19, 2025

Superlubricity, a lubricating state in which the coefficient of friction (COF) is smaller than 0.01, has been achieved at macroscale variety aqueous solutions and oils, as well two-dimensional (2D) carbon materials; nevertheless, it rarely realized with polymer composites. In present work, superlubricity was composite on basis microcapsule technique, an effective self-lubricating method for composites by releasing lubricants demand. Solid submicrometer capsules were used basic units matrix composite, oil-containing microcapsules lubrication fillers. On this material design strategy, robust COF 0.003–0.009 wide temperature range (0–200 °C) under atmospheric conditions, could be kept sliding distance over 500 m. It found that trace oil released from interface favored formation hydrodynamic film boundary tribo-film ultralow shear strength. This work provided novel to achieve potentially expanded engineering application superlubricity.

Language: Английский

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