Perfluoropolyether(PFPE)oils pose challenges in terms of their compatibility with nanoparticle lubrication additives because of their unique molecular structure,limiting their lubrication performance enhancement.To ad...Perfluoropolyether(PFPE)oils pose challenges in terms of their compatibility with nanoparticle lubrication additives because of their unique molecular structure,limiting their lubrication performance enhancement.To address this issue,we propose the development of nanoparticle composite supramolecular gel lubricants,aiming to maintain the dispersion stability of molybdenum disulfide(MoS_(2))nanoparticles within PFPE lubricants.This was achieved by harnessing the self-assembled three-dimensional(3D)network structure of supramolecular gels to entrap MoS_(2)nanoparticles.The MoS_(2)nanoparticles tended to cluster and settle in PFPE oils.However,the MoS_(2)-composite PFPE supramolecular gel lubricant(gel@MoS_(2))exhibited exceptional dispersion stability over an extended period.MoS_(2)nanoparticles used as additives in PFPE-based supramolecular gel lubricants not only enhanced the mechanical strength but also retained outstanding thixotropic properties.Additionally,nanoparticles improved the extreme pressure performance,antifriction capabilities,and anti-wear properties of PFPE-based supramolecular gel lubricants under a high load of 300 N.Furthermore,the lubrication mechanism of the gel@MoS_(2)composites was elucidated using focused ion beam-transmission electron microscopy and X-ray photoelectron spectroscopy.During the friction process,the 3D networks of the supramolecular gels,held together by weak interaction forces such as hydrogen bonds,halogen bonds,and van der Waals forces,were disrupted under continuous shear forces.Consequently,some of the MoS_(2)nanoparticles and gelators migrated to the steel surface,forming a protective lubricating film.This research holds significant importance in prolonging the lifespan of equipment in critical sectors such as aerospace and aviation,where high-end lubrication is essential.展开更多
In this study, SU-8 and its composites are fabricated by blending 10 wt.% hexagonal boron nitride(h-BN) fillers with/without lubricants, such as 10 wt.% base oil(SN150) and 20 wt.% perfluoropolyether(PFPE). The thickn...In this study, SU-8 and its composites are fabricated by blending 10 wt.% hexagonal boron nitride(h-BN) fillers with/without lubricants, such as 10 wt.% base oil(SN150) and 20 wt.% perfluoropolyether(PFPE). The thickness of SU-8 and its composites coating is fabricated in the range ~100–105 μm. Further, SU-8 and its composites are characterized by a 3D optical profilometer, atomic force microscopy, scanning electron microscopy, a thermal gravimetric analyzer, a goniometer, a hardness tester, and an optical microscope. Under a tribology test performed at different normal loads of 2, 4, and 6 N and at a constant sliding speed of 0.28 m/s, the reduction in the initial and steady-state coefficient of friction is obtained to be ~0.08 and ~0.098, respectively, in comparison to SU-8(~0.42 and ~0.75), and the wear resistance is enhanced by more than 103 times that of pure SU-8. Moreover, the thermal stability is improved by ~80–120 ℃, and the hardness and elastic modulus by ~3 and ~2 times that of pure SU-8, respectively. The SU-8 composite reinforced with 10 wt.% h-BN and 20 wt.% PFPE demonstrated the best thermo-mechanical and tribological properties with a nano-textured surface of high hydrophobicity.展开更多
Triboelectric nanogenerator(TENG)based on triboelectrification has attracted wide attention due to its effective utilization of green energy sources such as marine energy.However,researches about liquid-liquid triboel...Triboelectric nanogenerator(TENG)based on triboelectrification has attracted wide attention due to its effective utilization of green energy sources such as marine energy.However,researches about liquid-liquid triboelectrification are still scanty as solid-liquid triboelectrification has been widely studied.Herein,this work focuses on the hydrophobic/slippery substrate-water interfacial triboelectrification based on the solid friction materials of polytetrafluoroethylene(PTFE)nanoparticles.The hydrophobic/slippery substrate-water interfacial triboelectrification are studied by assembling PTFE coated Al sheets and perfluoropolyether(PFPE)infused PTFE coated Al sheets(formed the slippery lubricant-infused surfaces(SLIPSs))as the friction electrode,and water as liquid friction materials,respectively.The results show that the hydrophobic TENG output performances improved as the PTFE nanoparticles cumulating,and the SLIPSs TENG output performances increased with the thinner PFPE thickness.Both the triboelectrification behavior of hydrophobic/SLIPSs TENG assembled in this work are dominated by the electron transfer.Thanks to the introduction of SLIPSs,the SLIPSs TENG exhibits superior stability and durability than the hydrophobic TENG.The investigation of hydrophobic/slippery substrate-water interfacial triboelectrification contributes to optimize the TENG performances,and expands the application in harsh environments including low temperature and high humidity on the ocean.展开更多
基金funding support of the National Natural Science Foundation of China(Nos.U21A20280,5240053531,and U23A20623)the Space Utilization System of China Manned Space Engineering(No.KJZ-YY-WCL02)+3 种基金the Key Research and Development Program in Shandong Province(No.SYS202203)the Gansu Province Science and Technology Plan(Nos.22ZD6GA002,22ZD6GA025,and 24ZD13GA001)the Shandong Provincial Natural Science Foundation(Nos.ZR2023QB014 and ZR2024ZD26)the Taishan Scholars Program.
文摘Perfluoropolyether(PFPE)oils pose challenges in terms of their compatibility with nanoparticle lubrication additives because of their unique molecular structure,limiting their lubrication performance enhancement.To address this issue,we propose the development of nanoparticle composite supramolecular gel lubricants,aiming to maintain the dispersion stability of molybdenum disulfide(MoS_(2))nanoparticles within PFPE lubricants.This was achieved by harnessing the self-assembled three-dimensional(3D)network structure of supramolecular gels to entrap MoS_(2)nanoparticles.The MoS_(2)nanoparticles tended to cluster and settle in PFPE oils.However,the MoS_(2)-composite PFPE supramolecular gel lubricant(gel@MoS_(2))exhibited exceptional dispersion stability over an extended period.MoS_(2)nanoparticles used as additives in PFPE-based supramolecular gel lubricants not only enhanced the mechanical strength but also retained outstanding thixotropic properties.Additionally,nanoparticles improved the extreme pressure performance,antifriction capabilities,and anti-wear properties of PFPE-based supramolecular gel lubricants under a high load of 300 N.Furthermore,the lubrication mechanism of the gel@MoS_(2)composites was elucidated using focused ion beam-transmission electron microscopy and X-ray photoelectron spectroscopy.During the friction process,the 3D networks of the supramolecular gels,held together by weak interaction forces such as hydrogen bonds,halogen bonds,and van der Waals forces,were disrupted under continuous shear forces.Consequently,some of the MoS_(2)nanoparticles and gelators migrated to the steel surface,forming a protective lubricating film.This research holds significant importance in prolonging the lifespan of equipment in critical sectors such as aerospace and aviation,where high-end lubrication is essential.
文摘In this study, SU-8 and its composites are fabricated by blending 10 wt.% hexagonal boron nitride(h-BN) fillers with/without lubricants, such as 10 wt.% base oil(SN150) and 20 wt.% perfluoropolyether(PFPE). The thickness of SU-8 and its composites coating is fabricated in the range ~100–105 μm. Further, SU-8 and its composites are characterized by a 3D optical profilometer, atomic force microscopy, scanning electron microscopy, a thermal gravimetric analyzer, a goniometer, a hardness tester, and an optical microscope. Under a tribology test performed at different normal loads of 2, 4, and 6 N and at a constant sliding speed of 0.28 m/s, the reduction in the initial and steady-state coefficient of friction is obtained to be ~0.08 and ~0.098, respectively, in comparison to SU-8(~0.42 and ~0.75), and the wear resistance is enhanced by more than 103 times that of pure SU-8. Moreover, the thermal stability is improved by ~80–120 ℃, and the hardness and elastic modulus by ~3 and ~2 times that of pure SU-8, respectively. The SU-8 composite reinforced with 10 wt.% h-BN and 20 wt.% PFPE demonstrated the best thermo-mechanical and tribological properties with a nano-textured surface of high hydrophobicity.
基金financially supported by the National Natural Science Foundation of China(Nos.51735013 and 51905520).
文摘Triboelectric nanogenerator(TENG)based on triboelectrification has attracted wide attention due to its effective utilization of green energy sources such as marine energy.However,researches about liquid-liquid triboelectrification are still scanty as solid-liquid triboelectrification has been widely studied.Herein,this work focuses on the hydrophobic/slippery substrate-water interfacial triboelectrification based on the solid friction materials of polytetrafluoroethylene(PTFE)nanoparticles.The hydrophobic/slippery substrate-water interfacial triboelectrification are studied by assembling PTFE coated Al sheets and perfluoropolyether(PFPE)infused PTFE coated Al sheets(formed the slippery lubricant-infused surfaces(SLIPSs))as the friction electrode,and water as liquid friction materials,respectively.The results show that the hydrophobic TENG output performances improved as the PTFE nanoparticles cumulating,and the SLIPSs TENG output performances increased with the thinner PFPE thickness.Both the triboelectrification behavior of hydrophobic/SLIPSs TENG assembled in this work are dominated by the electron transfer.Thanks to the introduction of SLIPSs,the SLIPSs TENG exhibits superior stability and durability than the hydrophobic TENG.The investigation of hydrophobic/slippery substrate-water interfacial triboelectrification contributes to optimize the TENG performances,and expands the application in harsh environments including low temperature and high humidity on the ocean.
