Proton exchange membrane fuel cells(PEMFCs)have gained increasing interests as promising power sources due to their ability to convert hydrogen and oxygen directly into electricity with high efficiency and zero greenh...Proton exchange membrane fuel cells(PEMFCs)have gained increasing interests as promising power sources due to their ability to convert hydrogen and oxygen directly into electricity with high efficiency and zero greenhouse gas emissions.Bipolar plates(BPs)are considered as a critical component of PEMFCs,serving to collect current,separate gases,distribute the flow field,and conduct heat.This paper reviews the technical status and advancements in BP materials,with special focus on strategies for enhancing interfacial contact resistance(ICR)and corrosion resistance through conductive polymer(CP)coatings.First,commonly used BP materials in PEMFCs are summarized.Then,the advantages and limitations of various coatings for metallic BPs are discussed.Finally,recent progress in CP coatings for metallic BPs,aimed at achieving high corrosion resistance and low ICR,is comprehensively reviewed.展开更多
Passive daytime radiative cooling has great potential for energy conservation and sustainable development.Polymer-based radiative cooling materials have received much attention due to their excellent cooling performan...Passive daytime radiative cooling has great potential for energy conservation and sustainable development.Polymer-based radiative cooling materials have received much attention due to their excellent cooling performance and scalable potential.However,the use of large amounts of organic solvents,the long cycle time,and the complexity of the preparation process have limited their development.Herein,we report a two-step cold-press sintering method for the preparation of a polymer radiative cooler,which is free of organic solvents.For demonstration,a polyvinylidene fluoride-hexafluoropropylene copolymer(PVDF-HFP)coating with a solar reflectance of 97.4%and an emissivity of 0.969 within the atmospheric window is prepared,which can achieve a sub-ambient cooling phenomenon with a temperature reduction of 4.8℃.Besides,the maximal radiative cooling power of 50.2 W/m^(2)is also obtained under sunlight.After the implementation of the proposed sintered PVDF-HFP coating in buildings,more than 10%of annual energy consumption can be saved in China.This work proposes a simple,environmentally friendly,and scalable processing method for the preparation of radiative cooling materials,facilitating the large-scale application of radiative cooling technology.展开更多
Coating polymer on the surface is an effective way to realize functional modification of the materials for diverse applications,which has been proved to enhance the stability of metal anodes in batteries.However,given...Coating polymer on the surface is an effective way to realize functional modification of the materials for diverse applications,which has been proved to enhance the stability of metal anodes in batteries.However,given the limited operability of coating from polymer dispersions,it is imperative to develop simple aqueous-based strategies from monomers for versatile polymer coating.Herein,a Ti_(3)C_(2)Tx MXene-assisted approach is proposed to construct polymer coating on zinc metal surfaces directly from the aqueous solution of monomers in an ice bath.By combining a doctor-blading method with spontaneous polymerization of monomers on the substrates at room temperature,a uniform,adhesive,and versatile coating layer assisted by a small amount of MXene is produced in one step.Additionally,MXene nanosheets serve as nanofillers to further enhance the mechanical strength and ionic conductivity of the polymer coating.Benefiting from good film formation and improved interfacial contact,the coated zinc anode exhibits a long cycling lifespan of over 1900 h.The assembled full cells show excellent cycling stability with a high capacity retention of 85.0%at 16 A g^(-1)over 2600 cycles.This work provides a simple and efficient way to produce polymer coatings directly from monomers,which may give new insights into design multifunctional polymer coatings for various applications.展开更多
Novel antibacterial polymer coatings were prepared by a facile thiol-yne click photopolymerization of 1-propargyl-3-allYl-l,3-diazanyl-2,4-cyclopentadiene bromide （[PAIMIBr） and tetra（3-mercapto-pro- pionate）penta...Novel antibacterial polymer coatings were prepared by a facile thiol-yne click photopolymerization of 1-propargyl-3-allYl-l,3-diazanyl-2,4-cyclopentadiene bromide （[PAIMIBr） and tetra（3-mercapto-pro- pionate）pentaerythritol （PETMP） （2：1 molar ratio） using 2,2-dimethoxy-2-phenylacetophenone （DMPA） as initiator. The antibacterial activity of the coatings was tested against Staphylococcus aureus （ATCC 292130） and Escherichia coli （ATCC 25922） by the dynamic shake method. The evaluation results revealed the antibacterial polymer coatings exhibited excellent inhibitory activity against S. aureus and E. coil, especially for S. aureus.展开更多
Organic polymer coatings have been commonly used in biomedical field,which play an important role in achieving biological antifouling,drug delivery,and bacteriostasis.With the continuous development of polymer science...Organic polymer coatings have been commonly used in biomedical field,which play an important role in achieving biological antifouling,drug delivery,and bacteriostasis.With the continuous development of polymer science,organic polymer coatings can be designed with complex and advanced functions,which is conducive to the construction of biomedical materials with different performances.According to different physical and chemical properties of materials,biomedical organic polymer coating materials are classified into zwitterionic polymers,non-ionic polymers,and biomacromolecules.The strategies of combining coatings with substrates include physical adsorption,chemical grafting,and self-adhesion.Though the coating materials and construction methods are different,many biomedical polymer coatings have been developed to achieve excellent performances,i.e.,enhanced lubrication,anti-inflammation,antifouling,antibacterial,drug release,anti-encrustation,anti-thrombosis,etc.Consequently,a large number of biomedical polymer coatings have been used in artificial lungs,ureteral stent,vascular flow diverter,and artificial joints.In this review,we summarize different types,properties,construction methods,biological functions,and clinical applications of biomedical organic polymer coatings,and prospect future direction for development of organic polymer coatings in biomedical field.It is anticipated that this review can be useful for the design and synthesis of functional organic polymer coatings with various biomedical purposes.展开更多
A new method was developed based on the electron beam vacuum dispersion（EBVD） technology to prepare the PTFE polymer coating of the new polymer quartz piezoelectric crystal sensor for testing liquor products. The ne...A new method was developed based on the electron beam vacuum dispersion（EBVD） technology to prepare the PTFE polymer coating of the new polymer quartz piezoelectric crystal sensor for testing liquor products. The new method was applied in the new EBVD equipment which we designed. A real-time system monitoring the polymer coating＇s thickness was designed for the new EBVD equipment according to the quartz crystal microbalance（QCM） principle, playing an important role in preparing stable and uniform PTFE polymer coatings of the same thickness. 30 pieces of PTFE polymer coatings on the surface of the quartz crystal basis were prepared with the PTFE polymer ultrafine powder（purity ≥ 99.99%）as the starting material. We obtained 30 pieces of new PTFE polymer sensors. By using scanning electron microscopy（SEM）, the structure of the PTFE polymer coating＇s column clusters was studied. One sample from the 30 pieces of new PTFE polymer sensors was analysed by SEM in four scales, i.e., 400×, 1000×, 10000×, and 25000×. It was shown that under the condition of high bias voltage and low bias current, uniformly PTFE polymer coating could be achieved, which indicates that the new EBVD equipment is suitable for mass production of stable and uniform polymer coating.展开更多
Enhancing cavern sealing is crucial for improving the efficiency of compressed air energy storage(CAES)in hard rock formations.This study introduced a novel approach using a nano-grade organosilicon polymer(NOSP)as a ...Enhancing cavern sealing is crucial for improving the efficiency of compressed air energy storage(CAES)in hard rock formations.This study introduced a novel approach using a nano-grade organosilicon polymer(NOSP)as a sealant,coupled with an air seepage evaluation model that incorporates Knudsen diffusion.Moreover,the initial coating application methods were outlined,and the advantages of using NOSP compared to other sealing materials,particularly regarding cost and construction techniques,were also examined and discussed.Experimental results indicated a significant reduction in permeability of rock specimens coated with a 7–10μm thick NOSP layer.Specifically,under a 0.5 MPa pulse pressure,the permeability decreased to less than 1 n D,and under a 4 MPa pulse pressure,it ranged between4.5×10^(-6)–5.5×10^(-6)m D,marking a 75%–80%decrease in granite permeability.The sealing efficacy of NOSP surpasses concrete and is comparable to rubber materials.The optimal viscosity for application lies between 95 and 105 KU,and the coating thickness should ideally range from 7 to 10μm,applied to substrates with less than 3%porosity.This study provides new insights into air transport and sealing mechanisms at the pore level,proposing NOSP as a cost-effective and simplified solution for CAES applications.展开更多
The purpose of this work is in development of the model that allows to investigate the conformations of macromolecules near the interface"dielectric-metal"depending on the conditions of formation of the poly...The purpose of this work is in development of the model that allows to investigate the conformations of macromolecules near the interface"dielectric-metal"depending on the conditions of formation of the polymer coating.In the modified model of"sticky tape",one part of macromolecule is anchored to the metal surface while the other can be elongated due to effective mean(molecular)field of dipolar type formed by free ends of other chains.The dynamic Monte-Carlo method for Langmuir's model is used for calculation of adhesion force taking into account the interaction energy of monomers with the metal surface.It is shown that conformation of polymer chain is defined by temperature conditions of its formation.The obtained results are confirmed by the data of production tests on polymer coatings in JSC"Severstal".展开更多
Developing advanced technologies to address the bacterial associated infections is an urgent requirement for metallic implants and devices.Here,we report a novel phosphonate/quaternary amine block polymer as the high-...Developing advanced technologies to address the bacterial associated infections is an urgent requirement for metallic implants and devices.Here,we report a novel phosphonate/quaternary amine block polymer as the high-efficiency antibacterial coating for metallic substrates.Three pDEMMP-b-pTMAEMA block polymers that bearing identical phosphonate segments(repeat units of 15)but varied cationic segments(repeat units of 8,45,and 70)were precisely prepared.Stable cationic polymer coatings were constructed on TC4 substrates based on the strong covalent binding between phosphonate group and metallic substrate.Robust relationship between the segment chain length of the polymer coating and the antibacterial property endowed to the substrates have been established based on quantitative and qualitative evaluations.Results showed that the antibacterial rate of the modified TC4 surface were 95.8%of S.aureus and 92.9%of E.coli cells attached.Interestingly,unlike the cationic free polymer or cationic hydrogels,the surface anchored cationic polymers do compromise the viability of the attached C2C12 cells but without significant cytotoxicity.In addition,the phosphonate/quate rnary amine block polymers can be easily constructed on titanium,stainless steel,and Ni/Cr alloy with significantly improved antibacterial property,indicating the generality of the block polymer for surface antibacterial modification of bio-metals.展开更多
The strain and temperature sensing performance of fiber-optic Bragg gratings （FBGs） with soft polymeric coating, which can be used to sense internal strain in superconducting coils, are evaluated under variable cryo...The strain and temperature sensing performance of fiber-optic Bragg gratings （FBGs） with soft polymeric coating, which can be used to sense internal strain in superconducting coils, are evaluated under variable cryogenic field and magnetic field. The response to a temperature and strain change of coated-soft polymeric FBGs is tested by comparing with those of coated-metal FBGs. The results indicate that the coated-soft polymeric FBGs can freely detect temperature and thermal strain, their At variable magnetic field, the tested results indicate accuracy and repeatability are also discussed in detail. that the cross-coupling effects of FBGs with different matrixes are not negligible to measure electromagnetic strain during fast excitation. The present results are expected to be able to provide basis measurements on the strain of pulsed superconducting magnet/cable （cable- around-conduit conductors, cable-in-conduit conductors）, independently or utilized together with other strain measurement methods.展开更多
Twice-painting technique was adopted to prepare heavy-duty anticorrosive coating films formed by aqueous latexes of copolymers of vinylidene chloride（VDC） with an acrylate, namely methyl acrylate（MA）, ethyl acryl...Twice-painting technique was adopted to prepare heavy-duty anticorrosive coating films formed by aqueous latexes of copolymers of vinylidene chloride（VDC） with an acrylate, namely methyl acrylate（MA）, ethyl acrylate（EA）, butyl acrylate（BA） or 2-ethylhexyl acrylate（EHA）. Harsh salt-spray corrosion tests demonstrated that the optimized twicepainting technique was that the acidic latex solution was adjusted to p H 5-6 for the first painting, while it was utilized directly for the second painting. The test of 600 h of harsh salt-spray corrosion showed that MA-VDC85 coating could protect the steel excellently, whereas the other acrylate-VDC coatings with 75%-90% VDC content could not protect the steel so effectively. Further corrosion test showed that（1） MA-VDC85 coating protected steel from loss of metallic luster for at least 1000 h of salt-spray corrosion;（2） adhesion of MA-VDC85 coating to steel was excellent for at least 800 h of saltspray corrosion, but became very poor after 1000 h. Differential scanning calorimetry, thermogravimetric analysis, X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy were used to evaluate the corroded MA-VDC85 film.展开更多
Four kinds of polymer coated urea(PCU)were put in distilled water at 30℃ to determine the variation of coating penetrability and give a precise description of the urea release kinetics. The urea release from PCU coul...Four kinds of polymer coated urea(PCU)were put in distilled water at 30℃ to determine the variation of coating penetrability and give a precise description of the urea release kinetics. The urea release from PCU could be divided into four stages: lag stage, swell stage, steady stage and decay stage. The release rate coefficient K, a measure of coating penetrability, was linearly increased at swell stage, but almost not variable at steady stage. At decay stage, the relation of X to time t could be described by the equation K= mtn-1where m and n are the coefficients). When n>1, the coating penetrability was gradually increased, and the urea release from PCU was accelerated; when n=1, the coating penetrability was steady, and the urea release from PCU obeyed the first-order kinetics; and when n<1.the coating penetrability was gradually decreased, and the urea release from PCU was delayed, resulting in a significant 'tailing effect'.展开更多
Superhydrophobic coatings have been considerably used in corrosion and its protection of metallic Mg.And the comprehensive performance(hydrophobicity,bonding strength,and corrosion resistance,etc.)of the top coating m...Superhydrophobic coatings have been considerably used in corrosion and its protection of metallic Mg.And the comprehensive performance(hydrophobicity,bonding strength,and corrosion resistance,etc.)of the top coating may be highly dependent on the physical and chemical properties of the primer or under coat.Herein,an integrated superhydrophobic polypropylene(PP)coating was fabricated on the micro-arc oxidized Mg substrate via one-step dipping.Surface morphologies and chemical compositions of the composite coating were examined through Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD),and field-emission scanning electron microscopy(FESEM)together with X-ray photoelectron spectroscopy(XPS).The surface wettability of the coating was determined by contact angle and sliding angle.The corrosion-resistant performance was evaluated via electrochemical and immersion measurements.The results showed that the hybrid coating possessed micron-scaled granular structure on the surface with a high water contact angle of 167.2±0.8°and a low water sliding angle of 2.7±0.5°.The corrosion resistance of superhydrophobic coating was obviously enhanced with a low corrosion current density of 8.76×10^(−9)A/cm^(2),and the coating still maintained integrity after 248 h of immersion in 3.5wt%NaCl aqueous solution.The MAO coating provides better adhesion of PP to the surface.Hence,the superhydrophobic coating exhibited superior bonding strength,corrosion resistance and durability.展开更多
Mg has received much attention as a next-generation implantable material owing to its biocompatibility,bone-like mechanical properties,and biodegradability in physiological environments.The application of various poly...Mg has received much attention as a next-generation implantable material owing to its biocompatibility,bone-like mechanical properties,and biodegradability in physiological environments.The application of various polymer coatings has been conducted in the past to reduce the rapid formation of hydrogen gas and the local change in pH during the initial phase of the chemical reaction with the body fluids.Here,we propose femtosecond(fs)laser-mediated Mg surface patterning for significant enhancement of the binding strength of the coating material,which eventually reduces the corrosion rate.Analyses of the structural,physical,crystallographic,and chemical properties of the Mg surface have been conducted in order to understand the mechanism by which the surface adhesion increases between Mg and the polymer coating layer.Depending on the fs laser conditions,the surface structure becomes rough owing to the presence of several microscaled pits and grooves of nanoporous MgO,resulting in a tightly bonded poly(lactic-co-glycolic acid)(PLGA)layer.The corrosion rate of the PLGA-coated,fs laser-treated Mg is considerably slow compared with the non-treated Mg;the treated Mg is also more biocompatible compared with the non-treated Mg.The fs laser-based surface modification technique offers a simple and quick method for introducing a rough coating on Mg;further,it does not require any chemical treatment,thereby overcoming a potential obstacle for its clinical use.展开更多
Hexagonal boron nitride(h-BN)fillers are incorporated into poly(vinyl butyral)(PVB)coatings to improve the corrosion protection performance of copper.It has been revealed that the h-BN fillers exhibit an excellent dis...Hexagonal boron nitride(h-BN)fillers are incorporated into poly(vinyl butyral)(PVB)coatings to improve the corrosion protection performance of copper.It has been revealed that the h-BN fillers exhibit an excellent dispersiblility in PVB coating due to the non-covalent interactions between h-BN fillers and the PVB molecules.Electrochemical characterization reveals that the corrosion resistance of the BN-reinforced PVB(BN-P)coating is 5-6 orders of magnitude higher than that of the pristine PVB coating.Photographs and metallography show that the copper substrate beneath the BN-P coating does not suffer from corrosion after immersion for 2 months,indicating that the BN-P coating can provide a long-term protective barrier for the underlying copper substrate.Loading 0-0.25 g h-BN fillers in 2.0 g PVB,the corrosion protection performance increases with increasing the loading of h-BN fillers.The scratch test results suggest that h-BN fillers do not accelerate copper corrosion when the BN-P coating is damaged.展开更多
A double-layer aluminum consisting of an aluminum core and a shellof SiO2 and polyacrylic acid was synthesized.This modified aluminum was used to improve the corrosion resistance and dispersive property of aluminum in...A double-layer aluminum consisting of an aluminum core and a shellof SiO2 and polyacrylic acid was synthesized.This modified aluminum was used to improve the corrosion resistance and dispersive property of aluminum in waterborne media.TEM,FTIR,XPS,and EDX determination showed that PAA and SiO2 were coated on the surface of aluminum.Evolved hydrogen detection showed that the corrosion resistance of composite particle had been markedly improved.Maximum corrosion inhibition efficiency of SiO2 coated aluminum（SiO2@Al）was 95.1% while that of double-layer coated aluminum（PAA/SiO2@Al）was 98.8%.Meanwhile,polyacrylic acid layer improved the agglomeration of aluminum significantly.According to the dispersibility test,the particle size of 50% volume fraction [d（0.5）] of aluminum,SiO2@Aland PAA/SiO2@Alwere 42,53,and 34 μm,respectively.展开更多
The paper presents results of investigation on the erosive wear kinetics of epoxy coatings modified with alumina or silica nanoparticles. Natural weathering caused a decrease of their erosive wear resistance. After a ...The paper presents results of investigation on the erosive wear kinetics of epoxy coatings modified with alumina or silica nanoparticles. Natural weathering caused a decrease of their erosive wear resistance. After a 3-year natural weathering, highest erosive wear resistance showed the epoxy coating modified with alumina nanoparticles.展开更多
In recent years, graphene has been widely employed in the field of metal corrosion protection owing to its outstanding impermeability and chemical stability, with examples of such metal protection including pure graph...In recent years, graphene has been widely employed in the field of metal corrosion protection owing to its outstanding impermeability and chemical stability, with examples of such metal protection including pure graphene coatings and graphene-based composite coatings. But the conductive graphene could promote the electrochemical reaction at the interface and accelerate the corrosion of metal substrates. More emerging graphene-like 2D nanosheets are attracting research attention for the application of metal anticorrosion, because of their barrier properties and poor conductivity, mainly including boron nitride(BN),molybdenum disulfide(MoS_(2)), zirconium phosphate(ZrP), and titanium carbide(MXene). In this review,the application of these graphene-like 2D nanosheets to metal protection is comprehensively reviewed.First, the general preparation methods of 2D nanosheets are briefly introduced. Second, surface functionalization of 2D nanosheets, including covalent and non-covalent modification, is described in detail.Third, the anticorrosion performance and optimization measures of pure 2D nanosheets coatings are summarized. Next, the protection performance, anticorrosive mechanism, and optimizations of 2D nanosheets composite coatings are presented. Finally, the future development of 2D nanosheets-based anticorrosive coatings has been prospected, and the challenges in the industrial application are discussed.展开更多
Inorganic coating was fabricated on the surface of the porous Si3N4 ceramic by polymer derived（PD） and spraying technology, via using vinyl-polysilazane（PSN-1） as a preceramic polymer and Si3N4 and lithium alumino...Inorganic coating was fabricated on the surface of the porous Si3N4 ceramic by polymer derived（PD） and spraying technology, via using vinyl-polysilazane（PSN-1） as a preceramic polymer and Si3N4 and lithium aluminosilicate（LAS） powders as fillers. The phase and microstructure of the coatings were analyzed by X-ray diffraction（XRD） analysis and scanning electron microscopy（SEM）, respectively. The effect of the coatings on mechanical property and humidity resistance of the porous Si3N4 ceramic was investigated. The experimental results showed that we successfully fabricated the uniform and dense coating which preferably combined with the substrate upon the addition of fillers. The bending strength of the porous Si3N4 ceramic sprayed the coating increased by more than 18%, and the surface hardness increased by 1.7 times. The apparent porosity of the materials reduced by an average of 97.7%, and water absorption was below 0.5%. Therefore, the prepared coating with preferable density had an obviously moisture-proof and enhanced effect on the porous Si3N4 ceramic.展开更多
The main objective was to study the anticorrosion performance of poly（o-toluidine）/nano ZrO2/epoxy composite coating.Poly（o-toluidine）/nano ZrO2 composite was prepared by in situ polymerization of o-toluidine mono...The main objective was to study the anticorrosion performance of poly（o-toluidine）/nano ZrO2/epoxy composite coating.Poly（o-toluidine）/nano ZrO2 composite was prepared by in situ polymerization of o-toluidine monomer in the presence of nano ZrO2 particles.Fourier transformation infrared spectroscopy（FT-IR）,UV-visible spectroscopy（UV-vis）,X-ray diffraction（XRD）,Scanning electron microscopy（SEM）,and Thermogravimetric analysis（TGA） were used to characterize the composition and structure of the composite.Poly（o-toluidine）/nano ZrO2 composite was mixed with epoxy resin through a solution blending method and the three components poly（o-toluidine）/nano ZrO2/epoxy composite coating was coated onto the surface of steel sample by the brush coating method.The anticorrosion performance of poly（o-toluidine）/nano ZrO2/epoxy composite coating on steel sample was studied by polarization curve and electrochemical impendence spectroscopy in 3.5% Na Cl solution as corrosion environment and also compared with that of poly（o-toluidine）/epoxy composite coating and pure epoxy coating.It was observed that the composite coating containing poly（otoluidine）/nano ZrO2 composite has got higher corrosion protection ability than that of poly（o-toluidine）.The electrochemical measurement results demonstrated that poly（o-toluidine） fillers improve the electrochemical anticorrosion performance of epoxy coating and the addition of nano ZrO2 particles increases the tortuosity of the diffusion pathway of corrosive substances.展开更多
基金supported by the National Natural Science Foundation of China under Grant Nos.12102310 and U21A20113the Guangdong Basic and Applied Basic Research Foundation under Grant No.2020A1515110818+2 种基金the Inovation Team Project for Colleges and Universities of Guangdong Province under Grant No.2023KCXTD030the Key Project of Biomedicine and Health in Colleges and Universities of Guangdong Province under Grant No.2021ZDZX2055the Medical Science and Technology Research Fund of Guangdong Province under Grant No.A2022004.
文摘Proton exchange membrane fuel cells(PEMFCs)have gained increasing interests as promising power sources due to their ability to convert hydrogen and oxygen directly into electricity with high efficiency and zero greenhouse gas emissions.Bipolar plates(BPs)are considered as a critical component of PEMFCs,serving to collect current,separate gases,distribute the flow field,and conduct heat.This paper reviews the technical status and advancements in BP materials,with special focus on strategies for enhancing interfacial contact resistance(ICR)and corrosion resistance through conductive polymer(CP)coatings.First,commonly used BP materials in PEMFCs are summarized.Then,the advantages and limitations of various coatings for metallic BPs are discussed.Finally,recent progress in CP coatings for metallic BPs,aimed at achieving high corrosion resistance and low ICR,is comprehensively reviewed.
基金supported by the National Natural Science Foundation of China(NSFC 52130601 and 52106276)the Young Elite Scientists Sponsorship Program by CAST(2023QNRC001)+1 种基金the University of Science and Technology of China-Southwest University of Science and Technology Counterpart Cooperation and Development Joint Fund(24LHJJ09)the USTC Center for Micro and Nanoscale Research and Fabrication。
文摘Passive daytime radiative cooling has great potential for energy conservation and sustainable development.Polymer-based radiative cooling materials have received much attention due to their excellent cooling performance and scalable potential.However,the use of large amounts of organic solvents,the long cycle time,and the complexity of the preparation process have limited their development.Herein,we report a two-step cold-press sintering method for the preparation of a polymer radiative cooler,which is free of organic solvents.For demonstration,a polyvinylidene fluoride-hexafluoropropylene copolymer(PVDF-HFP)coating with a solar reflectance of 97.4%and an emissivity of 0.969 within the atmospheric window is prepared,which can achieve a sub-ambient cooling phenomenon with a temperature reduction of 4.8℃.Besides,the maximal radiative cooling power of 50.2 W/m^(2)is also obtained under sunlight.After the implementation of the proposed sintered PVDF-HFP coating in buildings,more than 10%of annual energy consumption can be saved in China.This work proposes a simple,environmentally friendly,and scalable processing method for the preparation of radiative cooling materials,facilitating the large-scale application of radiative cooling technology.
基金the support from the National Natural Science Foundation of China(51972228 and 22109116)the TJU Nanoyang-Neware Joint Laboratory for Energy Innovation。
文摘Coating polymer on the surface is an effective way to realize functional modification of the materials for diverse applications,which has been proved to enhance the stability of metal anodes in batteries.However,given the limited operability of coating from polymer dispersions,it is imperative to develop simple aqueous-based strategies from monomers for versatile polymer coating.Herein,a Ti_(3)C_(2)Tx MXene-assisted approach is proposed to construct polymer coating on zinc metal surfaces directly from the aqueous solution of monomers in an ice bath.By combining a doctor-blading method with spontaneous polymerization of monomers on the substrates at room temperature,a uniform,adhesive,and versatile coating layer assisted by a small amount of MXene is produced in one step.Additionally,MXene nanosheets serve as nanofillers to further enhance the mechanical strength and ionic conductivity of the polymer coating.Benefiting from good film formation and improved interfacial contact,the coated zinc anode exhibits a long cycling lifespan of over 1900 h.The assembled full cells show excellent cycling stability with a high capacity retention of 85.0%at 16 A g^(-1)over 2600 cycles.This work provides a simple and efficient way to produce polymer coatings directly from monomers,which may give new insights into design multifunctional polymer coatings for various applications.
文摘Novel antibacterial polymer coatings were prepared by a facile thiol-yne click photopolymerization of 1-propargyl-3-allYl-l,3-diazanyl-2,4-cyclopentadiene bromide （[PAIMIBr） and tetra（3-mercapto-pro- pionate）pentaerythritol （PETMP） （2：1 molar ratio） using 2,2-dimethoxy-2-phenylacetophenone （DMPA） as initiator. The antibacterial activity of the coatings was tested against Staphylococcus aureus （ATCC 292130） and Escherichia coli （ATCC 25922） by the dynamic shake method. The evaluation results revealed the antibacterial polymer coatings exhibited excellent inhibitory activity against S. aureus and E. coil, especially for S. aureus.
基金supported by the National Natural Science Foundation of China(Nos.52275199 and 52335004)Beijing–Tianjin–Hebei Fundamental Research Cooperation Project(No.J230001).
文摘Organic polymer coatings have been commonly used in biomedical field,which play an important role in achieving biological antifouling,drug delivery,and bacteriostasis.With the continuous development of polymer science,organic polymer coatings can be designed with complex and advanced functions,which is conducive to the construction of biomedical materials with different performances.According to different physical and chemical properties of materials,biomedical organic polymer coating materials are classified into zwitterionic polymers,non-ionic polymers,and biomacromolecules.The strategies of combining coatings with substrates include physical adsorption,chemical grafting,and self-adhesion.Though the coating materials and construction methods are different,many biomedical polymer coatings have been developed to achieve excellent performances,i.e.,enhanced lubrication,anti-inflammation,antifouling,antibacterial,drug release,anti-encrustation,anti-thrombosis,etc.Consequently,a large number of biomedical polymer coatings have been used in artificial lungs,ureteral stent,vascular flow diverter,and artificial joints.In this review,we summarize different types,properties,construction methods,biological functions,and clinical applications of biomedical organic polymer coatings,and prospect future direction for development of organic polymer coatings in biomedical field.It is anticipated that this review can be useful for the design and synthesis of functional organic polymer coatings with various biomedical purposes.
基金Project supported by the National High Technology Research and Development Program of China(Grant No.2013AA030901)
文摘A new method was developed based on the electron beam vacuum dispersion（EBVD） technology to prepare the PTFE polymer coating of the new polymer quartz piezoelectric crystal sensor for testing liquor products. The new method was applied in the new EBVD equipment which we designed. A real-time system monitoring the polymer coating＇s thickness was designed for the new EBVD equipment according to the quartz crystal microbalance（QCM） principle, playing an important role in preparing stable and uniform PTFE polymer coatings of the same thickness. 30 pieces of PTFE polymer coatings on the surface of the quartz crystal basis were prepared with the PTFE polymer ultrafine powder（purity ≥ 99.99%）as the starting material. We obtained 30 pieces of new PTFE polymer sensors. By using scanning electron microscopy（SEM）, the structure of the PTFE polymer coating＇s column clusters was studied. One sample from the 30 pieces of new PTFE polymer sensors was analysed by SEM in four scales, i.e., 400×, 1000×, 10000×, and 25000×. It was shown that under the condition of high bias voltage and low bias current, uniformly PTFE polymer coating could be achieved, which indicates that the new EBVD equipment is suitable for mass production of stable and uniform polymer coating.
基金supported by the National Natural Science Foundation of China(No.42272321)Hubei Provincial Key Research Projects(Nos.2022BAA093 and 2022BAD163)+1 种基金Major Scientific and Technological Special Project of Jiangxi Province(No.2023ACG01004)WSGRI Engineering&Surveying Incorporation Limited(No.6120230256)。
文摘Enhancing cavern sealing is crucial for improving the efficiency of compressed air energy storage(CAES)in hard rock formations.This study introduced a novel approach using a nano-grade organosilicon polymer(NOSP)as a sealant,coupled with an air seepage evaluation model that incorporates Knudsen diffusion.Moreover,the initial coating application methods were outlined,and the advantages of using NOSP compared to other sealing materials,particularly regarding cost and construction techniques,were also examined and discussed.Experimental results indicated a significant reduction in permeability of rock specimens coated with a 7–10μm thick NOSP layer.Specifically,under a 0.5 MPa pulse pressure,the permeability decreased to less than 1 n D,and under a 4 MPa pulse pressure,it ranged between4.5×10^(-6)–5.5×10^(-6)m D,marking a 75%–80%decrease in granite permeability.The sealing efficacy of NOSP surpasses concrete and is comparable to rubber materials.The optimal viscosity for application lies between 95 and 105 KU,and the coating thickness should ideally range from 7 to 10μm,applied to substrates with less than 3%porosity.This study provides new insights into air transport and sealing mechanisms at the pore level,proposing NOSP as a cost-effective and simplified solution for CAES applications.
基金The study results are obtained at the performance of State Task No.2014/267 from 31.01.2014,No.1715.
文摘The purpose of this work is in development of the model that allows to investigate the conformations of macromolecules near the interface"dielectric-metal"depending on the conditions of formation of the polymer coating.In the modified model of"sticky tape",one part of macromolecule is anchored to the metal surface while the other can be elongated due to effective mean(molecular)field of dipolar type formed by free ends of other chains.The dynamic Monte-Carlo method for Langmuir's model is used for calculation of adhesion force taking into account the interaction energy of monomers with the metal surface.It is shown that conformation of polymer chain is defined by temperature conditions of its formation.The obtained results are confirmed by the data of production tests on polymer coatings in JSC"Severstal".
基金the grant supports from the National Natural Science Foundation of China(No.21504046)the Six Talent Peaks Project in Jiangsu Province(SWYY-060)+1 种基金the Projects of Nanjing Normal University(No.184080H20192184080H10386)。
文摘Developing advanced technologies to address the bacterial associated infections is an urgent requirement for metallic implants and devices.Here,we report a novel phosphonate/quaternary amine block polymer as the high-efficiency antibacterial coating for metallic substrates.Three pDEMMP-b-pTMAEMA block polymers that bearing identical phosphonate segments(repeat units of 15)but varied cationic segments(repeat units of 8,45,and 70)were precisely prepared.Stable cationic polymer coatings were constructed on TC4 substrates based on the strong covalent binding between phosphonate group and metallic substrate.Robust relationship between the segment chain length of the polymer coating and the antibacterial property endowed to the substrates have been established based on quantitative and qualitative evaluations.Results showed that the antibacterial rate of the modified TC4 surface were 95.8%of S.aureus and 92.9%of E.coli cells attached.Interestingly,unlike the cationic free polymer or cationic hydrogels,the surface anchored cationic polymers do compromise the viability of the attached C2C12 cells but without significant cytotoxicity.In addition,the phosphonate/quate rnary amine block polymers can be easily constructed on titanium,stainless steel,and Ni/Cr alloy with significantly improved antibacterial property,indicating the generality of the block polymer for surface antibacterial modification of bio-metals.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11302225,11121202 and 11327802the National Key Project of Magneto-Constrained Fusion Energy Development Program under Grant No 2013GB110002the Postdoctoral Science Foundation of China under Grant No 2014M560820
文摘The strain and temperature sensing performance of fiber-optic Bragg gratings （FBGs） with soft polymeric coating, which can be used to sense internal strain in superconducting coils, are evaluated under variable cryogenic field and magnetic field. The response to a temperature and strain change of coated-soft polymeric FBGs is tested by comparing with those of coated-metal FBGs. The results indicate that the coated-soft polymeric FBGs can freely detect temperature and thermal strain, their At variable magnetic field, the tested results indicate accuracy and repeatability are also discussed in detail. that the cross-coupling effects of FBGs with different matrixes are not negligible to measure electromagnetic strain during fast excitation. The present results are expected to be able to provide basis measurements on the strain of pulsed superconducting magnet/cable （cable- around-conduit conductors, cable-in-conduit conductors）, independently or utilized together with other strain measurement methods.
基金financially supported by the Program for New Century Excellent Talents in Universitiesthe National Natural Science Foundation of China(No.21074088)
文摘Twice-painting technique was adopted to prepare heavy-duty anticorrosive coating films formed by aqueous latexes of copolymers of vinylidene chloride（VDC） with an acrylate, namely methyl acrylate（MA）, ethyl acrylate（EA）, butyl acrylate（BA） or 2-ethylhexyl acrylate（EHA）. Harsh salt-spray corrosion tests demonstrated that the optimized twicepainting technique was that the acidic latex solution was adjusted to p H 5-6 for the first painting, while it was utilized directly for the second painting. The test of 600 h of harsh salt-spray corrosion showed that MA-VDC85 coating could protect the steel excellently, whereas the other acrylate-VDC coatings with 75%-90% VDC content could not protect the steel so effectively. Further corrosion test showed that（1） MA-VDC85 coating protected steel from loss of metallic luster for at least 1000 h of salt-spray corrosion;（2） adhesion of MA-VDC85 coating to steel was excellent for at least 800 h of saltspray corrosion, but became very poor after 1000 h. Differential scanning calorimetry, thermogravimetric analysis, X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy were used to evaluate the corroded MA-VDC85 film.
基金supported by the National 863 Program,Ministry of Science and Technology of China(2001AA246021)the Knowledge Innovation Engineering of the Chinese Academy of Sciences(KZCX2-402).
文摘Four kinds of polymer coated urea(PCU)were put in distilled water at 30℃ to determine the variation of coating penetrability and give a precise description of the urea release kinetics. The urea release from PCU could be divided into four stages: lag stage, swell stage, steady stage and decay stage. The release rate coefficient K, a measure of coating penetrability, was linearly increased at swell stage, but almost not variable at steady stage. At decay stage, the relation of X to time t could be described by the equation K= mtn-1where m and n are the coefficients). When n>1, the coating penetrability was gradually increased, and the urea release from PCU was accelerated; when n=1, the coating penetrability was steady, and the urea release from PCU obeyed the first-order kinetics; and when n<1.the coating penetrability was gradually decreased, and the urea release from PCU was delayed, resulting in a significant 'tailing effect'.
基金This work was supported by the National Natural Science Foundation of China(51571134)the SDUST Research Fund(2014TDJH104).
文摘Superhydrophobic coatings have been considerably used in corrosion and its protection of metallic Mg.And the comprehensive performance(hydrophobicity,bonding strength,and corrosion resistance,etc.)of the top coating may be highly dependent on the physical and chemical properties of the primer or under coat.Herein,an integrated superhydrophobic polypropylene(PP)coating was fabricated on the micro-arc oxidized Mg substrate via one-step dipping.Surface morphologies and chemical compositions of the composite coating were examined through Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD),and field-emission scanning electron microscopy(FESEM)together with X-ray photoelectron spectroscopy(XPS).The surface wettability of the coating was determined by contact angle and sliding angle.The corrosion-resistant performance was evaluated via electrochemical and immersion measurements.The results showed that the hybrid coating possessed micron-scaled granular structure on the surface with a high water contact angle of 167.2±0.8°and a low water sliding angle of 2.7±0.5°.The corrosion resistance of superhydrophobic coating was obviously enhanced with a low corrosion current density of 8.76×10^(−9)A/cm^(2),and the coating still maintained integrity after 248 h of immersion in 3.5wt%NaCl aqueous solution.The MAO coating provides better adhesion of PP to the surface.Hence,the superhydrophobic coating exhibited superior bonding strength,corrosion resistance and durability.
基金This work was supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.2020R1A2C2010413)the KIST project(2E30341)。
文摘Mg has received much attention as a next-generation implantable material owing to its biocompatibility,bone-like mechanical properties,and biodegradability in physiological environments.The application of various polymer coatings has been conducted in the past to reduce the rapid formation of hydrogen gas and the local change in pH during the initial phase of the chemical reaction with the body fluids.Here,we propose femtosecond(fs)laser-mediated Mg surface patterning for significant enhancement of the binding strength of the coating material,which eventually reduces the corrosion rate.Analyses of the structural,physical,crystallographic,and chemical properties of the Mg surface have been conducted in order to understand the mechanism by which the surface adhesion increases between Mg and the polymer coating layer.Depending on the fs laser conditions,the surface structure becomes rough owing to the presence of several microscaled pits and grooves of nanoporous MgO,resulting in a tightly bonded poly(lactic-co-glycolic acid)(PLGA)layer.The corrosion rate of the PLGA-coated,fs laser-treated Mg is considerably slow compared with the non-treated Mg;the treated Mg is also more biocompatible compared with the non-treated Mg.The fs laser-based surface modification technique offers a simple and quick method for introducing a rough coating on Mg;further,it does not require any chemical treatment,thereby overcoming a potential obstacle for its clinical use.
基金supported by the National Natural Science Foundation of China(Nos.U1706225,42006046,2019GGX102014,and 2019YFC0312103)the Research Fund of Open Studio for Marine Corrosion and Protection,Pilot National Laboratory for Marine Science and Technology(Qingdao,No.HYFSKF-201804)。
文摘Hexagonal boron nitride(h-BN)fillers are incorporated into poly(vinyl butyral)(PVB)coatings to improve the corrosion protection performance of copper.It has been revealed that the h-BN fillers exhibit an excellent dispersiblility in PVB coating due to the non-covalent interactions between h-BN fillers and the PVB molecules.Electrochemical characterization reveals that the corrosion resistance of the BN-reinforced PVB(BN-P)coating is 5-6 orders of magnitude higher than that of the pristine PVB coating.Photographs and metallography show that the copper substrate beneath the BN-P coating does not suffer from corrosion after immersion for 2 months,indicating that the BN-P coating can provide a long-term protective barrier for the underlying copper substrate.Loading 0-0.25 g h-BN fillers in 2.0 g PVB,the corrosion protection performance increases with increasing the loading of h-BN fillers.The scratch test results suggest that h-BN fillers do not accelerate copper corrosion when the BN-P coating is damaged.
基金Funded by the National Natural Science Foundation of China(31170558)the Fundamental Research Funds for the Central Universities(410500006)
文摘A double-layer aluminum consisting of an aluminum core and a shellof SiO2 and polyacrylic acid was synthesized.This modified aluminum was used to improve the corrosion resistance and dispersive property of aluminum in waterborne media.TEM,FTIR,XPS,and EDX determination showed that PAA and SiO2 were coated on the surface of aluminum.Evolved hydrogen detection showed that the corrosion resistance of composite particle had been markedly improved.Maximum corrosion inhibition efficiency of SiO2 coated aluminum（SiO2@Al）was 95.1% while that of double-layer coated aluminum（PAA/SiO2@Al）was 98.8%.Meanwhile,polyacrylic acid layer improved the agglomeration of aluminum significantly.According to the dispersibility test,the particle size of 50% volume fraction [d（0.5）] of aluminum,SiO2@Aland PAA/SiO2@Alwere 42,53,and 34 μm,respectively.
文摘The paper presents results of investigation on the erosive wear kinetics of epoxy coatings modified with alumina or silica nanoparticles. Natural weathering caused a decrease of their erosive wear resistance. After a 3-year natural weathering, highest erosive wear resistance showed the epoxy coating modified with alumina nanoparticles.
基金financially supported by the National Natural Science Foundation of China(No.51973231)Guangdong Basic and Applied Basic Research Foundation(Nos.2021A1515012449,2019A1515010743)+1 种基金the Fundamental Research Funds for the Central Universities,Sun Yat-sen University(No.20lgzd17)Open Project from State Key Laboratory of Inorganic Synthesis and Preparative Chemistry(No.2020-31)。
文摘In recent years, graphene has been widely employed in the field of metal corrosion protection owing to its outstanding impermeability and chemical stability, with examples of such metal protection including pure graphene coatings and graphene-based composite coatings. But the conductive graphene could promote the electrochemical reaction at the interface and accelerate the corrosion of metal substrates. More emerging graphene-like 2D nanosheets are attracting research attention for the application of metal anticorrosion, because of their barrier properties and poor conductivity, mainly including boron nitride(BN),molybdenum disulfide(MoS_(2)), zirconium phosphate(ZrP), and titanium carbide(MXene). In this review,the application of these graphene-like 2D nanosheets to metal protection is comprehensively reviewed.First, the general preparation methods of 2D nanosheets are briefly introduced. Second, surface functionalization of 2D nanosheets, including covalent and non-covalent modification, is described in detail.Third, the anticorrosion performance and optimization measures of pure 2D nanosheets coatings are summarized. Next, the protection performance, anticorrosive mechanism, and optimizations of 2D nanosheets composite coatings are presented. Finally, the future development of 2D nanosheets-based anticorrosive coatings has been prospected, and the challenges in the industrial application are discussed.
文摘Inorganic coating was fabricated on the surface of the porous Si3N4 ceramic by polymer derived（PD） and spraying technology, via using vinyl-polysilazane（PSN-1） as a preceramic polymer and Si3N4 and lithium aluminosilicate（LAS） powders as fillers. The phase and microstructure of the coatings were analyzed by X-ray diffraction（XRD） analysis and scanning electron microscopy（SEM）, respectively. The effect of the coatings on mechanical property and humidity resistance of the porous Si3N4 ceramic was investigated. The experimental results showed that we successfully fabricated the uniform and dense coating which preferably combined with the substrate upon the addition of fillers. The bending strength of the porous Si3N4 ceramic sprayed the coating increased by more than 18%, and the surface hardness increased by 1.7 times. The apparent porosity of the materials reduced by an average of 97.7%, and water absorption was below 0.5%. Therefore, the prepared coating with preferable density had an obviously moisture-proof and enhanced effect on the porous Si3N4 ceramic.
基金Funded by the Innovation Project of Guangxi Graduate Education(No.YCSZ2014202)
文摘The main objective was to study the anticorrosion performance of poly（o-toluidine）/nano ZrO2/epoxy composite coating.Poly（o-toluidine）/nano ZrO2 composite was prepared by in situ polymerization of o-toluidine monomer in the presence of nano ZrO2 particles.Fourier transformation infrared spectroscopy（FT-IR）,UV-visible spectroscopy（UV-vis）,X-ray diffraction（XRD）,Scanning electron microscopy（SEM）,and Thermogravimetric analysis（TGA） were used to characterize the composition and structure of the composite.Poly（o-toluidine）/nano ZrO2 composite was mixed with epoxy resin through a solution blending method and the three components poly（o-toluidine）/nano ZrO2/epoxy composite coating was coated onto the surface of steel sample by the brush coating method.The anticorrosion performance of poly（o-toluidine）/nano ZrO2/epoxy composite coating on steel sample was studied by polarization curve and electrochemical impendence spectroscopy in 3.5% Na Cl solution as corrosion environment and also compared with that of poly（o-toluidine）/epoxy composite coating and pure epoxy coating.It was observed that the composite coating containing poly（otoluidine）/nano ZrO2 composite has got higher corrosion protection ability than that of poly（o-toluidine）.The electrochemical measurement results demonstrated that poly（o-toluidine） fillers improve the electrochemical anticorrosion performance of epoxy coating and the addition of nano ZrO2 particles increases the tortuosity of the diffusion pathway of corrosive substances.
