Perfluoropolyether(PFPE)lubricants are a kind of high-molecular polymer with many excellent properties.However,the use of PFPEs in the nuclear industry can lead to partial decomposition and carrying radionuclides,resu...Perfluoropolyether(PFPE)lubricants are a kind of high-molecular polymer with many excellent properties.However,the use of PFPEs in the nuclear industry can lead to partial decomposition and carrying radionuclides,resulting in a large amount of radioactive waste PFPE lubricants annually.Moreover,radioactive waste PFPE lubricants are difficult to be effectively treated due to their high stability,the risk of possible leakage of radionuclides,and hypertoxic fluorine-containing by-products.In this study,without any precedent,a strategy of Mn O_(2)-catalyzed decomposition and Na_(2)CO_(3)-immobilized conversion was proposed for PFPE lubricant decomposition and fluorine immobilization simultaneously based on the Lewis acid-base and oxygen vacancies concept.A high fluorine conversion efficiency of 95.4%was achieved.Meanwhile,the mechanism of decomposition suggested that Mn O_(2)mainly provided Lewis acid sites and attacked the(basic)fluorine or oxygen atoms in PFPE molecules.The decomposition of PFPE chains was proceed down and volatile fluorine-containing gas was released by partial electron transfer,intramolecular disproportionation reaction,and unzipping fashion.Subsequently,gas by-products could be further oxidized and then immobilized into fluoride salts by carbonate solid absorbents.Overall,this study provides a simple,safe,and potentially practical strategy for the harmless conversion of refractory fluorinated organic wastes,especially perfluoropolymers.展开更多
The spread of perfluoropolyether （PFPE） droplets on solid surfaces has been measured from the top-down view through a microscope system. Effects of substrates, molecular weight and end-group functionality on spreadi...The spread of perfluoropolyether （PFPE） droplets on solid surfaces has been measured from the top-down view through a microscope system. Effects of substrates, molecular weight and end-group functionality on spreading of the PFPE droplets have been studied experimentally and the results were compared with those by molecular dynamics （MD） simulations. Silicon wafer and diamond-like carbon （DLC） substrates were used to study the effect of substrates on spreading. Two types of PFPE, Z-dol and Z-tetraol, with the same chain structure and various molecular weights （2000 and 4000 g/mol） were employed in experiments. Effect of molecular weight has been investigated through comparing the spreading of Z-dol 2000 and Z-dol 4000, and it is found that the increase of molecular weight will decrease the mobility of PFPE. Comparison between spreading of Z-dol and Z-tetraol of the same molecular weight proved that functional end group plays a significant role on the spreading of PFPE, which confirmed the MD simulation results.展开更多
The geometries of CF3OCF2, CF3OCFCF3 and CF3OCF2CF2 radicals were investigated by density functional theory（DFT） method. The calculated results indicate that all the three radicals have pyramidal shapes at their cen...The geometries of CF3OCF2, CF3OCFCF3 and CF3OCF2CF2 radicals were investigated by density functional theory（DFT） method. The calculated results indicate that all the three radicals have pyramidal shapes at their centers, and the aC is one top of the pyramids. Based on the DFT optimized geometries, the hyperfine coupling constants（hfec＇s） of the 19F atoms of the three radicals were calculated by B3LYP, MP2（full） and QCISD（full） methods. The calculated values agree with the experimental values, especially for the a values of Fa, the a values are 125.6× 10 -4, 104.2× 10 - 4, and 83.2×10 -4 T of CF3OCF2, CF3OCFCF3 and CF3OCF2CF2, respectively. These results better explain the experimental observation.展开更多
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
A kind of vacuum lubricating grease was prepared by using perfluoropolyether as base oil,perfluorinated polymer as thickener,and self-made additives.The colloidal stability of the grease was greatly improved by introd...A kind of vacuum lubricating grease was prepared by using perfluoropolyether as base oil,perfluorinated polymer as thickener,and self-made additives.The colloidal stability of the grease was greatly improved by introducing a colloidal structure modifier.The rheological properties of the self-made grease(SMG),such as viscosity versus time,thixotropy,etc.,were studied by a rheometer at different temperatures and were compared with those of foreign brand grease(FBG).The results show that the performance of SMG reached the level of similar FBG,and some properties such as mechanical stability,colloidal stability,extreme pressure and antiwear properties were better.It can be used for long life lubrication of moving parts in a vacuum environment.展开更多
Lubricant spreading on solid substrates has drawn considerable attention not only for the microscopic wetting theory but also for the dramatic application in head-disk interface of magnetic storage drive systems. Mole...Lubricant spreading on solid substrates has drawn considerable attention not only for the microscopic wetting theory but also for the dramatic application in head-disk interface of magnetic storage drive systems. Molecular dynamic simulation based on a coarse-grained bead-spring model has been used to study such a spreading process. The spreading profiles indicate that the hydrogen bonds among lubricant molecules and the hydrogen bonds between lubricant molecules and polar atoms of solid substrates will complicate the spreading process in a tremendous degree. The hydrogen bonds among lubricant molecules will strengthen the lubricant combination intensity, which may hinder most molecules from flowing down to the substrates and diffusing along the substrates. And the hydrogen bonds between lubricant molecules and polar atoms of solid substrates will confine the lubricant molecules around polar atoms, which may hinder the molecules from diffusing along the substrates and cause precursor film to vanish.展开更多
Molecular dynamic simulations based on a coarse-gralned, bead-spring model are adopted to investigate the spreading of both nonfunctional and functional perfluoropolyether （PFPE） on solid substrates. For nonfunction...Molecular dynamic simulations based on a coarse-gralned, bead-spring model are adopted to investigate the spreading of both nonfunctional and functional perfluoropolyether （PFPE） on solid substrates. For nonfunctional PFPE, the spreading generally exhibits a smooth profile with a precursor film. The spreading profiles on different substrates are compared, which indicate that the bead-substrate interaction has a significant effect on the spreading behaviour, especially on the formation of the precursor film. For functional PFPE, the spreading generally exhibits a complicated terraced profile. The spreading profiles with different endbeads are compared, which indicate that the endbead-substrate interaction and the endbead-endbead interaction, especially the latter, have a significant effect on the spreading behaviour.展开更多
Surfactants are central to droplet-based microfluidics,where they stabilize immiscible interfaces,prevent coalescence,and enable precise control of discrete fluid volumes for biological and chemical applications.Recen...Surfactants are central to droplet-based microfluidics,where they stabilize immiscible interfaces,prevent coalescence,and enable precise control of discrete fluid volumes for biological and chemical applications.Recent efforts in fluorosurfactant design have emphasized how variations in hydrophilic head groups,fluorinated tail architecture,and synthesis strategies determine performance in droplet systems.This review surveys advances from conventional polyethylene glycol(PEG)-perfluoropolyether(PFPE)architectures to emerging alternatives with nonionic polar head groups,highlighting those with the greatest potential to advance the field.Particular attention is given to reversible addition-fragmentation chain transfer(RAFT)polymerization,which has revolutionized fluorosurfactant development by enabling precise molecular control and tunable properties.This has allowed the integration of responsive functionalities,including temperature-sensitive N-isopropylacrylamide(NIPAM),pH-responsive 2-(dimethylamino)ethyl acrylate(DMAEA),and zwitterionic monomers,thereby greatly expanding functional versatility.Such innovations improve droplet stability,suppress molecular exchange,and enhance biocompatibility under challenging experimental conditions.These advanced fluorosurfactants demonstrate exceptional utility across a spectrum of biological applications,including high-throughput screening,droplet digital PCR,single-cell genomics,cell encapsulation,and three-dimensional culture systems.Collectively,they establish a foundation for next-generation microfluidic technologies that demand robust compartmentalization with minimal biological interference.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
Perfluoropolyether(PFPE)is a promising material for protective coatings on Li metal anodes due to its chemical inertness and minimal swelling in electrolytes.However,a conventional PFPE coating with poor ionic conduct...Perfluoropolyether(PFPE)is a promising material for protective coatings on Li metal anodes due to its chemical inertness and minimal swelling in electrolytes.However,a conventional PFPE coating with poor ionic conductivity and mechanical stability is still not satisfactory for long-term cycling of Li anodes.Here,we design and synthesize an adaptive and high-conductivity supramolecular polymer(PFPE-EG-I).This polymer is constructed from PFPE chains,ethylene glycol(EG)segments,and hydrogen-bonding moieties derived from isophoronediisocyanate,serving as a multifaceted artificial solid electrolyte interphase(SEI).The incorporated EG segments enhance the Li+conductivity of the SEI,and the hydrogen-bonding units introduce a dynamic self-adaptive behavior to the polymer matrix.A solution-processed PFPE-EG-I coating is demonstrated to promote uniform Li deposition and mitigate side reactions between Li and the electrolyte.Consequently,this leads to enhanced coulombic efficiency and prolonged cycle longevity in lithium metal batteries(LMBs).The innovative design of this multifunctional artificial SEI offers a promising avenue for the realization of dendrite-free Li anodes,paving the way for the advancement of high-performance LMBs.展开更多
基金Sichuan Science and Technology Program (No.2021YJ0482)the Fundamental Research Funds for the Central Universities (No.2021SCU12087)。
文摘Perfluoropolyether(PFPE)lubricants are a kind of high-molecular polymer with many excellent properties.However,the use of PFPEs in the nuclear industry can lead to partial decomposition and carrying radionuclides,resulting in a large amount of radioactive waste PFPE lubricants annually.Moreover,radioactive waste PFPE lubricants are difficult to be effectively treated due to their high stability,the risk of possible leakage of radionuclides,and hypertoxic fluorine-containing by-products.In this study,without any precedent,a strategy of Mn O_(2)-catalyzed decomposition and Na_(2)CO_(3)-immobilized conversion was proposed for PFPE lubricant decomposition and fluorine immobilization simultaneously based on the Lewis acid-base and oxygen vacancies concept.A high fluorine conversion efficiency of 95.4%was achieved.Meanwhile,the mechanism of decomposition suggested that Mn O_(2)mainly provided Lewis acid sites and attacked the(basic)fluorine or oxygen atoms in PFPE molecules.The decomposition of PFPE chains was proceed down and volatile fluorine-containing gas was released by partial electron transfer,intramolecular disproportionation reaction,and unzipping fashion.Subsequently,gas by-products could be further oxidized and then immobilized into fluoride salts by carbonate solid absorbents.Overall,this study provides a simple,safe,and potentially practical strategy for the harmless conversion of refractory fluorinated organic wastes,especially perfluoropolymers.
基金Project supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No20060003025)the State Key Development Program for Basic Research of China(Grant No2003CB716201)
文摘The spread of perfluoropolyether （PFPE） droplets on solid surfaces has been measured from the top-down view through a microscope system. Effects of substrates, molecular weight and end-group functionality on spreading of the PFPE droplets have been studied experimentally and the results were compared with those by molecular dynamics （MD） simulations. Silicon wafer and diamond-like carbon （DLC） substrates were used to study the effect of substrates on spreading. Two types of PFPE, Z-dol and Z-tetraol, with the same chain structure and various molecular weights （2000 and 4000 g/mol） were employed in experiments. Effect of molecular weight has been investigated through comparing the spreading of Z-dol 2000 and Z-dol 4000, and it is found that the increase of molecular weight will decrease the mobility of PFPE. Comparison between spreading of Z-dol and Z-tetraol of the same molecular weight proved that functional end group plays a significant role on the spreading of PFPE, which confirmed the MD simulation results.
基金Supported by the Major State Basic Research Development Programs of China(No2007CB815206)the National Natural Science Foundation of China(Nos20873010, 20720102038)the Fundamental Research Funds for the Central Universities of China
文摘The geometries of CF3OCF2, CF3OCFCF3 and CF3OCF2CF2 radicals were investigated by density functional theory（DFT） method. The calculated results indicate that all the three radicals have pyramidal shapes at their centers, and the aC is one top of the pyramids. Based on the DFT optimized geometries, the hyperfine coupling constants（hfec＇s） of the 19F atoms of the three radicals were calculated by B3LYP, MP2（full） and QCISD（full） methods. The calculated values agree with the experimental values, especially for the a values of Fa, the a values are 125.6× 10 -4, 104.2× 10 - 4, and 83.2×10 -4 T of CF3OCF2, CF3OCFCF3 and CF3OCF2CF2, respectively. These results better explain the experimental observation.
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.
文摘A kind of vacuum lubricating grease was prepared by using perfluoropolyether as base oil,perfluorinated polymer as thickener,and self-made additives.The colloidal stability of the grease was greatly improved by introducing a colloidal structure modifier.The rheological properties of the self-made grease(SMG),such as viscosity versus time,thixotropy,etc.,were studied by a rheometer at different temperatures and were compared with those of foreign brand grease(FBG).The results show that the performance of SMG reached the level of similar FBG,and some properties such as mechanical stability,colloidal stability,extreme pressure and antiwear properties were better.It can be used for long life lubrication of moving parts in a vacuum environment.
基金Project supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No 20060003025)the Science Foundation for Post Doctoral Research from the Ministry of Science and Technology of China (Grant No 20070420017)the 111 Project (Grant No B08043) and the National Natural Science Foundation of China (Grant No 50705009)
文摘Lubricant spreading on solid substrates has drawn considerable attention not only for the microscopic wetting theory but also for the dramatic application in head-disk interface of magnetic storage drive systems. Molecular dynamic simulation based on a coarse-grained bead-spring model has been used to study such a spreading process. The spreading profiles indicate that the hydrogen bonds among lubricant molecules and the hydrogen bonds between lubricant molecules and polar atoms of solid substrates will complicate the spreading process in a tremendous degree. The hydrogen bonds among lubricant molecules will strengthen the lubricant combination intensity, which may hinder most molecules from flowing down to the substrates and diffusing along the substrates. And the hydrogen bonds between lubricant molecules and polar atoms of solid substrates will confine the lubricant molecules around polar atoms, which may hinder the molecules from diffusing along the substrates and cause precursor film to vanish.
基金Project supported by the National Natural Science Foundation of China （Grant No 50390060） and the State Key Development Program for Basic Research of China （Grant No 2003CB716201）.
文摘Molecular dynamic simulations based on a coarse-gralned, bead-spring model are adopted to investigate the spreading of both nonfunctional and functional perfluoropolyether （PFPE） on solid substrates. For nonfunctional PFPE, the spreading generally exhibits a smooth profile with a precursor film. The spreading profiles on different substrates are compared, which indicate that the bead-substrate interaction has a significant effect on the spreading behaviour, especially on the formation of the precursor film. For functional PFPE, the spreading generally exhibits a complicated terraced profile. The spreading profiles with different endbeads are compared, which indicate that the endbead-substrate interaction and the endbead-endbead interaction, especially the latter, have a significant effect on the spreading behaviour.
基金support from the National Health and Medical Research Council(APP1196850)Australian Research Council(DP240102315)+1 种基金Queensland-Chinese Academy of Sciences(Q-CAS)Collaborative Science Fund(QCAS2022016)H.P.received funding from the Innovative Ingredients Program at Australia’s Food and Beverage Accelerator(FaBA),and UQ Biosustainability Hub.
文摘Surfactants are central to droplet-based microfluidics,where they stabilize immiscible interfaces,prevent coalescence,and enable precise control of discrete fluid volumes for biological and chemical applications.Recent efforts in fluorosurfactant design have emphasized how variations in hydrophilic head groups,fluorinated tail architecture,and synthesis strategies determine performance in droplet systems.This review surveys advances from conventional polyethylene glycol(PEG)-perfluoropolyether(PFPE)architectures to emerging alternatives with nonionic polar head groups,highlighting those with the greatest potential to advance the field.Particular attention is given to reversible addition-fragmentation chain transfer(RAFT)polymerization,which has revolutionized fluorosurfactant development by enabling precise molecular control and tunable properties.This has allowed the integration of responsive functionalities,including temperature-sensitive N-isopropylacrylamide(NIPAM),pH-responsive 2-(dimethylamino)ethyl acrylate(DMAEA),and zwitterionic monomers,thereby greatly expanding functional versatility.Such innovations improve droplet stability,suppress molecular exchange,and enhance biocompatibility under challenging experimental conditions.These advanced fluorosurfactants demonstrate exceptional utility across a spectrum of biological applications,including high-throughput screening,droplet digital PCR,single-cell genomics,cell encapsulation,and three-dimensional culture systems.Collectively,they establish a foundation for next-generation microfluidic technologies that demand robust compartmentalization with minimal biological interference.
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.
基金National Natural Science Foundation of China(grant no.22075164)Fundamental Research Funds for the Central Universities,Southwest Jiaotong University(grant no.2682023CX005).
文摘Perfluoropolyether(PFPE)is a promising material for protective coatings on Li metal anodes due to its chemical inertness and minimal swelling in electrolytes.However,a conventional PFPE coating with poor ionic conductivity and mechanical stability is still not satisfactory for long-term cycling of Li anodes.Here,we design and synthesize an adaptive and high-conductivity supramolecular polymer(PFPE-EG-I).This polymer is constructed from PFPE chains,ethylene glycol(EG)segments,and hydrogen-bonding moieties derived from isophoronediisocyanate,serving as a multifaceted artificial solid electrolyte interphase(SEI).The incorporated EG segments enhance the Li+conductivity of the SEI,and the hydrogen-bonding units introduce a dynamic self-adaptive behavior to the polymer matrix.A solution-processed PFPE-EG-I coating is demonstrated to promote uniform Li deposition and mitigate side reactions between Li and the electrolyte.Consequently,this leads to enhanced coulombic efficiency and prolonged cycle longevity in lithium metal batteries(LMBs).The innovative design of this multifunctional artificial SEI offers a promising avenue for the realization of dendrite-free Li anodes,paving the way for the advancement of high-performance LMBs.
