Surface modification of fabrics is an effective way to endow them with antifouling properties while still maintaining their key advantages such as comfort,softness and stretchability.Herein,an atmospheric pressure die...Surface modification of fabrics is an effective way to endow them with antifouling properties while still maintaining their key advantages such as comfort,softness and stretchability.Herein,an atmospheric pressure dielectric barrier discharge(DBD)plasma method is demonstrated for the processing of silk fabrics using 1H,1H,2H,2H-perfluorodecyltriethoxysilane(PFDS)as the precursor.The results showed the successful grafting of PFDS groups onto the surface of silk fabrics without causing damage.Meanwhile,the gas temperature is rather low during the whole processing procedure,suggesting the non-equilibrium characteristics of DBD plasma.The influence on fabrics of the processing parameters(PFDS concentration,plasma treatment time and plasma discharge power)was systematically investigated.An optimum processing condition was determined to be a PFDS concentration of 8wt%,a plasma processing time of 40 s and a plasma power of 11.87 W.However,with prolonged plasma processing time or enhanced plasma power,the plasma-grafted PFDS films could be degraded.Further study revealed that plasma processing of silk fabrics with PFDS would lead to a change in their chemical composition and surface roughness.As a result,the surface energy of the fabrics was reduced,accompanied by improved water and oil repellency as well as enhanced antifouling performance.Besides,the plasma-grafted PFDS films also had good durability and stability.By extending the method to polyester and wool against different oil-/water-based stains,the DBD plasma surface modification technique demonstrated good versatility in improving the antifouling properties of fabrics.This work provides guidance for the surface modification of fabrics using DBD plasma to confer them with desirable functionalities.展开更多
Solving intrinsic structural problems such as low conductivity is the main challenge to promote the commercial application of Li_(2)TiSiO_(5).In this study,Li_(2)TiSiO_(5) is synthesized by the sol-gelmethod,and the s...Solving intrinsic structural problems such as low conductivity is the main challenge to promote the commercial application of Li_(2)TiSiO_(5).In this study,Li_(2)TiSiO_(5) is synthesized by the sol-gelmethod,and the surface modification of Li_(2)TiSiO_(5) is carried out at different temperatures using low-temperature plasma to enhance its lithium storage performance.The morphological structure and electrochemical tests demonstrate that plasma treatment can improve the degree of agglomeration.The peak position of the plasma-treated Li_(2)TiSiO_(5) is shifted to a lower angle,and the shift angle increases with increasing sputtering power.Li_(2)TiSiO_(5) after 300 W bombardment shows excellent capacity(144.7 mA·hg^(−1)after 500 cycles at 0.1 Ag^(−1))and rate performance(140 mA·hg^(−1)at 5 Ag^(−1)).Electrochemical analysis indicates that excellent electrochemical performance is attributed to the enhancement of electronic and ionic conductivity by plasma bombardment.展开更多
An atmospheric pressure argon plasma brush with air addition is employed to treat polyethylene terephthalate(PET)surface in order to improve its hydrophilicity.Results indicate that the plasma plume generated by the p...An atmospheric pressure argon plasma brush with air addition is employed to treat polyethylene terephthalate(PET)surface in order to improve its hydrophilicity.Results indicate that the plasma plume generated by the plasma brush presents periodically pulsed current despite a direct current voltage is applied.Voltage-current curve reveals that there is a transition from a Townsend discharge regime to a glow one during one discharge period.Optical emission spectrum indicates that more oxygen atoms are produced in the plume with increasing air content,which leads to the better hydrophilicity of PET surface after plasma treatment.Besides,an aging behavior is also observed.The hydrophilicity improvement is attributed to the production of oxygen functional groups,which increase in number with increasing air content.Moreover,some grain-like structures are observed on the treated PET surface,and its mean roughness increases with increasing air content.These results are of great importance for the hydrophilicity improvement of PET surface with a large scale.展开更多
The aging effects of the contact angle and surface energy on polyethylene terephthalate (PET) have been investigated with surface modification by water vapor plasma. The experimental results show that the contact ang...The aging effects of the contact angle and surface energy on polyethylene terephthalate (PET) have been investigated with surface modification by water vapor plasma. The experimental results show that the contact angle of water and PET decreases obviously and surface energy increases. However, with the increase of the aging time, the contact angle and surface energy change back gradually to original state.展开更多
In this study, compounded surface modification technology-high current pulsed electron beam （HCPEB） ＋ micro-plasma oxidation （MPO） was applied to treat ZK60 Mg alloys. The characteristics of the microstructure of...In this study, compounded surface modification technology-high current pulsed electron beam （HCPEB） ＋ micro-plasma oxidation （MPO） was applied to treat ZK60 Mg alloys. The characteristics of the microstructure of ZK60 Mg alloy after single MPO and HCPEB＋MPO compounded treatment were investigated by SEM. The results showed that the density of the ceramic layer of HCPEB＋MPO-treated ZK60 Mg alloy was improved and defects were reduced compared to that under MPO treatment alone. Surface modified layer of ZK60 Mg alloys treated by HCPEB＋MPO was divided into three zones, namely the top loose ceramic zone, middle compact zone and inside HCPEB-induced melted zone. Corrosion resistance of ZK60 Mg alloy before and after the compounded surface modification was measured in a solution of 3.5% NaCl by potentiodynamic polarization curves. It was found that the corrosion current density of ZK60 Mg alloys could be reduced by about three orders of magnitude, from 311μA/cm^2 of the original sample to 0.2μA/cm^2 of the HCPEB＋MPO-treated sample. This indicates the great application potential of the HCPEB＋MPO compounded surface modification technology in improving the corrosion resistance of ZK60 Mg alloys in the future.展开更多
Indium gallium tin oxide(IGTO)thin films have the potential for high mobility and lowtemperature processing,which makes them suitable for applications such as display backplanes and high-voltage switching devices.Howe...Indium gallium tin oxide(IGTO)thin films have the potential for high mobility and lowtemperature processing,which makes them suitable for applications such as display backplanes and high-voltage switching devices.However,very few studies have investigated the plasmaetching characteristics of IGTO and changes in its properties after etching.In this study,the etching characteristics of IGTO were investigated using Cl_(2)/Ar plasma,and changes in surface properties were analyzed.Results showed that the etch rate increased with an increase in the proportion of Cl_(2),with the highest etch rate observed at 69 nm min^(-1)in pure Cl_(2)plasma with a gas flow rate of 100 sccm.Furthermore,increased radio-frequency power caused a rise in the etch rate,while a process pressure of 15 m Torr was optimal.The primary etching mechanism for IGTO thin films under Cl_(2)plasma was a chemical reaction,and an increased work function indicated the occurrence of defects on the surface.In addition,the etching process reduced the surface roughness of Cl_(2)-containing plasma,whereas the etching process in pure Ar plasma increased surface roughness.This study contributes to a better understanding of the plasmaetching characteristics of IGTO and changes in its properties after etching,providing valuable insights for IGTO-based applications.展开更多
The inner surface modification process by plasma-based low-energy ion implantation（PBLEII）with an electron cyclotron resonance（ECR）microwave plasma source located at the central axis of a cylindrical tube is model...The inner surface modification process by plasma-based low-energy ion implantation（PBLEII）with an electron cyclotron resonance（ECR）microwave plasma source located at the central axis of a cylindrical tube is modeled to optimize the low-energy ion implantation parameters for industrial applications.In this paper,a magnetized plasma diffusion fluid model has been established to describe the plasma nonuniformity caused by plasma diffusion under an axial magnetic field during the pulse-off time of low pulsed negative bias.Using this plasma density distribution as the initial condition,a sheath collisional fluid model is built up to describe the sheath evolution and ion implantation during the pulse-on time.The plasma nonuniformity at the end of the pulse-off time is more apparent along the radial direction compared with that in the axial direction due to the geometry of the linear plasma source in the center and the difference between perpendicular and parallel plasma diffusion coefficients with respect to the magnetic field.The normalized nitrogen plasma densities on the inner and outer surfaces of the tube are observed to be about 0.39 and 0.24,respectively,of which the value is 1 at the central plasma source.After a 5μs pulse-on time,in the area less than 2 cm from the end of the tube,the nitrogen ion implantation energy decreases from 1.5 keV to 1.3 keV and the ion implantation angle increases from several degrees to more than 40°;both variations reduce the nitrogen ion implantation depth.However,the nitrogen ion implantation dose peaks of about 2×10^（10）-7×10^（10）ions/cm^2 in this area are 2-4 times higher than that of 1.18×10^（10）ions/cm^2 and 1.63×10^（10）ions/cm^2 on the inner and outer surfaces of the tube.The sufficient ion implantation dose ensures an acceptable modification effect near the end of the tube under the low energy and large angle conditions for nitrogen ion implantation,because the modification effect is mainly determined by the ion implantation dose,just as the mass transfer process in PBLEII is dominated by low-energy ion implantation and thermal diffusion.Therefore,a comparatively uniform surface modification by the low-energy nitrogen ion implantation is achieved along the cylindrical tube on both the inner and outer surfaces.展开更多
Cold plasma techniques were used to treat the surface of Kevlar-49 fibers. The dynamic parameters of wetting, contact-angles and surface energy of the fiber before and alter the treatment were compared to see the chan...Cold plasma techniques were used to treat the surface of Kevlar-49 fibers. The dynamic parameters of wetting, contact-angles and surface energy of the fiber before and alter the treatment were compared to see the changes in the wetting property. ESCA and electron spin resonance were utilized to examine the chemical composition and the attached free radicals of the fiber surface. The results, together with changes in the magnitude of the contact-angle and the number of free radicals with time after the plasma treatment do not show any ageing effect. Single filament test revealed that the tensile strength was not impaired but even improved somewhat after the plasma treatment. The experiment shows that the interlaminar shear strength of Kevlar fiber reinforced epoxy resin compo- site is increased for more than 60％% after the treatment.展开更多
The effects of non-thermal plasma （NTP） treatment on biomass in the form of pulverized palmbased empty fruit bunches （EFB） are investigated. Specifically, this study investigates the effects of NTP treatment on th...The effects of non-thermal plasma （NTP） treatment on biomass in the form of pulverized palmbased empty fruit bunches （EFB） are investigated. Specifically, this study investigates the effects of NTP treatment on the surface reactivity, morphology, oxygen-to-carbon （O/C） ratio of the EFB at varying treatment times. The surface reactivity is determined by the reaction of antioxidant functional groups or reactive species with 2,2-diphenyl-l-picrylhydrazyl （DPPH）. By measuring the concentration of the DPPH with a spectrophotometer, the change in the amount of antioxidant functional groups can be measured to determine the surface reactivity. The reactions of the various lignin components in the EFB with respect to the NTP treatment are discussed by qualitatively assessing the changes in the Fourier transform infrared （FTIR） spectra. The surface morphology is examined by a scanning electron microscope. To determine the amount of oxygen deposited on the EFB by the air-based NTP treatment, the oxygen and carbon contents are measured by an energy dispersive x-ray detector to determine the O/C ratio. The results show that the NTP reactor produced reactive species such as atomic oxygen and ozone, increasing the surface reactivity and chemical scavenging rate of the EFB. Consequently, the surface morphology changed, with an observed rougher surface from the images of the EFB samples. The change in the appearance of the surface is accompanied by a high O/C ratio, and is caused by reactions of certain components of lignin due to the NTP treatment, The lignin component that was modified is believed to be syringyl, as the syringyl portion in the lignin of EFBs is higher compared to the other components. Syringyl components are detected in the range of F-FIR wavenumbers of 1109-1363 cm-1. With increasing NTP treatment times, the absorbance （of the peaks in the PTIR spectra） for syringyl related C-H and lignin associated C=C bonds decreases as the syringyl decomposes. The resulting release of carboxyl compounds increases the absorbance for the carbonyl C=O group. The results show that NTP treatment is able to modify the surface properties of EFB, and that the surface reactivity can be increased to improve their conversion and processing efficiencies.展开更多
The surface modification of nanometer carbon material has been studied by using an Induced Dielectric Barrier Discharge Plasma device (IDBD). The experimental results show that with different work gases and different ...The surface modification of nanometer carbon material has been studied by using an Induced Dielectric Barrier Discharge Plasma device (IDBD). The experimental results show that with different work gases and different discharge conditions, the surface behaviors of carbon black can be changed according to needs, including the use of different functional groups and the change of the surface roughness of carbon particles etc., which increased the grinding and dispersion abilities in binder.展开更多
Using argon as the work gas, the effects and mechanisms of poly（tetrafluoroethylene） （PTFE） film surface modification were investigated in a low pressure plasma reactor. Results show that higher hydrophilicity wit...Using argon as the work gas, the effects and mechanisms of poly（tetrafluoroethylene） （PTFE） film surface modification were investigated in a low pressure plasma reactor. Results show that higher hydrophilicity with little degradation, in terms of the scanning electron microscopy （SEM）, was obtained after treatment, especially when the sample was placed in the post-discharge area. More polar functional groups and higher surface free energy, especially the polar component, formed on the PTFE surface were responsible for the modification. For the relatively high purity radicals and rare discharge particles in the post-discharge area, the etching was restrained and the introducing reactions were enhanced, and thus, a better modification occurred there.展开更多
In this paper, an improved quasi-stable atmospheric pressure dielectric barrier discharge （DBD） plasma source is achieved after carefully controlled discharge voltage and current, discharge power, working gas, treat...In this paper, an improved quasi-stable atmospheric pressure dielectric barrier discharge （DBD） plasma source is achieved after carefully controlled discharge voltage and current, discharge power, working gas, treatment period, and gap between the electrodes. This plasma source has been used to modify the surface of Polybutylene Terephthalate （PBT） melt-blown nonwovens and Polyester （PET） fabrics, and the various influences on surface modification and the aging effect of treated polymeric materials have been systematically investigated. In addition, the method of spectrum analysis is also used for diagnosing plasma paramneters such as electron temperature. Experimental results indicate that both the wettablity and permeation of treated PBT melt-blown nonwovens and dyeing ability of treated PET fabrics are certainly improved.展开更多
Surfaces of optical elements are deposited by antireflection coatings (ARCs) to decrease the reflection of light. Surface needs treatment before depositing the ARC one of treatment processes by plasma for adhesion imp...Surfaces of optical elements are deposited by antireflection coatings (ARCs) to decrease the reflection of light. Surface needs treatment before depositing the ARC one of treatment processes by plasma for adhesion improvement and surface hardening. A comparison of RF and DC glow discharges treated CR-39 polymer films gives insight into the mechanism of these surface processes. The surface properties of the plasma-treated samples are examined by microscopy techniques include contact angle measurements, scanning electron microscopy (SEM), atomic force microscopy (AFM), infrared (IR) spectroscopy and refractive index measurements. Results show that the plasma treatment modifies the polymer surface in both composition and morphology. It is found that the surface wettability is enhanced after plasma treatment. It is found that, RF plasma is more effective than DC plasma in CR-39 surface modification, as it implants more oxygen atoms into the surface and makes the contact angle declining to a lower level.展开更多
To reduce Ni ion release and improve biocompatibility of NiTi alloy, the cathodic plasma electrolytic deposition （CPED） technique was used to fabricate ceramic coating onto a NiTi alloy surface. The formation of a c...To reduce Ni ion release and improve biocompatibility of NiTi alloy, the cathodic plasma electrolytic deposition （CPED） technique was used to fabricate ceramic coating onto a NiTi alloy surface. The formation of a coating with a rough and micro-textured surface was confirmed by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy, re- spectively. An inductively coupled plasma mass spectrometry test showed that the formed coating significantly reduced the release of Ni ions from the NiTi alloy in simulated body fluid. The in- fluence of CPED treated NiTi substrates on the biological behaviors of osteoblasts, including cell adhesion, cell viability, and osteogenic differentiation function （alkaline phosphatase）, was inves- tigated in vitro. Immunofluorescence staining of nuclei revealed that the CPED treated NiTi alloy was favorable for cell growth. Osteoblasts on CPED modified NiTi alloy showed greater cell viability than those for the native NiTi substrate after 4 and 7 days cultures. More importantly, osteoblasts cultured onto a modified NiTi sample displayed significantly higher differentiation lev-els of alkaline phosphatase. The results suggested that surface functionalization of NiTi alloy with ceramic coating via the CPED technique was beneficial for cell proliferation and differentiation. The approach presented here is useful for NiTi implants to enhance bone osseointegration and reduce Ni ion release in vitro.展开更多
The hot dipping process of pure aluminum on H13 steel substrates followed by plasma electrolytic oxidation(PEO) was studied to form alumina ceramic coatings for protective purpose.H13 steel bars were first dipped in p...The hot dipping process of pure aluminum on H13 steel substrates followed by plasma electrolytic oxidation(PEO) was studied to form alumina ceramic coatings for protective purpose.H13 steel bars were first dipped in pure aluminum melts,and then,a reactive iron-aluminum intermetallic layer grew at the interface between the melt and the steel substrate.The reactive layer was mainly composed of intermetallic Fe-Al(Fe_2Al_5);the thickness of aluminum layer and Fe-Al intermetallic layer were mainly influenced by dipping time(1.5～12.0 min) and dipping temperature(710～760 ℃).After PEO process,uniform Al_2O_3 ceramic coatings were deposited on the surface of aluminized steel.The element distribution,phase composition and morphology of the aluminized layer,and the ceramic coatings were characterized by SEM/EDS and XRD.The distribution of hardness across the composite coating is demonstrated,and the maximum value reaches 1864 HV.The thermal shock resistance of the coated sample is also well improved.展开更多
In this paper,plasma fluorination is combined with plasma silicon deposition to achieve step gradient modification on an epoxy resin surface.The physicochemical characteristics of samples are investigated and the elec...In this paper,plasma fluorination is combined with plasma silicon deposition to achieve step gradient modification on an epoxy resin surface.The physicochemical characteristics of samples are investigated and the electrical performances measured.The obtained results show that compared with untreated and single treated samples,the samples treated by step gradient modification significantly improve the flashover performance.According to experiment and simulation,the mechanism explanations are summarized as follows.First,it is found that the step gradient conductivity can effectively optimize the electric field distribution of a needle-needle electrode.Then,step gradient modification suppresses the accumulation of surface charge at the triple junction and makes the charge distribution more uniform.Furthermore,it can accelerate the surface dissipation on a high electrical field region and control the dissipation rate on a low electrical field region.All these results can restrain surface discharge and increase the flashover voltage.The step gradient modification method proposed in this paper provides a new idea for improving the surface insulation performance.展开更多
The flashover performance of insulating materials plays an important role in the development of high-voltage insulation systems.In this paper,silicone rubber(SIR)is modified by CF4 radio frequency capacitively coupled...The flashover performance of insulating materials plays an important role in the development of high-voltage insulation systems.In this paper,silicone rubber(SIR)is modified by CF4 radio frequency capacitively coupled plasma(CCP)for the improvement of surface insulation performance.The discharge mode and active particles of CCP are diagnosed by the digital single-lens reflex and the spectrometer.Scanning electron microscopy and x-ray photoelectron spectroscopy are used for the surface physicochemical properties of samples,while the surface charge dissipation,charge accumulation measurement,and flashover test are applied for the surface electrical characteristics.Experimental results show that the fluorocarbon groups can be grafted and the surface roughness increases after plasma treatment.Besides,the surface charge dissipation is decelerated and the positive charge accumulation is inhibited obviously for the treated samples.Furthermore,the surface flashover voltage can be increased by 26.67%after 10 min of treatment.It is considered that strong electron affinity of C–F and increased surface roughness can contribute to deepening surface traps,which not only inhibits the development of secondary electron emission avalanche but also alleviates the surface charge accumulation and finally improves the surface flashover voltage of SIR.展开更多
Enhancement of the surface hydrophilicity of biodegradable poly （D,L-lactic acid） （PLA） films is studied. The PLA films were treated by nitrogen plasma （PLA-N2） and nitro- gen/hydrogen plasma （PLA-N2/H2）, resp...Enhancement of the surface hydrophilicity of biodegradable poly （D,L-lactic acid） （PLA） films is studied. The PLA films were treated by nitrogen plasma （PLA-N2） and nitro- gen/hydrogen plasma （PLA-N2/H2）, respectively. The surface properties and microstructure of PLA-N2 and PLA-N2/H2 were studied by static contact angle measurement, surface free energy calculation, X-ray photoelectron spectroscopy （XPS） and atomic force microscopy （AFM）. It is confirmed that the surface hydrophilicity of PLA-N2 and PLA-N2/H2 was higher than that of pristine PLA, and the surface hydrophilicity of PLA-N2 films was better than that of PLA-N2/H2.展开更多
In this study, commercial poly vinyl chloride （PVC） films were treated by oxygen and argon plasmas in a cylindrical glass tube which was surrounded by a DC variable magnetic field, with different sample positions in...In this study, commercial poly vinyl chloride （PVC） films were treated by oxygen and argon plasmas in a cylindrical glass tube which was surrounded by a DC variable magnetic field, with different sample positions in the plasma reactor and also different exposure durations. Effects of the plasma treatment on the hydrophilic properties of the films were studied by mea- suring the water drop contact angle on the surface of the samples. The surface topography of the untreated and plasma treated films was analyzed and compared by atomic force microscopy （AFM）. The optical characteristic changes in treated samples were investigated using reflective spectrophotometry. Also, the chemical changes which appeared on the surface of the samples were investigated using Fourier transform infrared spectroscopy （FTIR）. The results show that the plasma treated PVC becomes more hydrophilic with an enhanced wettability. A sharp de- crease in the water contact angle may also be a consequence of the surface texturization. The aging effect on wettability of the samples was also investigated. The results show that the effect of oxygen plasma on the surface properties of the samples is more pronounced compared with that of argon plasma.展开更多
The surface charge accumulation on polymers often leads to surface flashover.Current solutions are mainly based on the introduction of inorganic fillers.The high-cost process and low compatibility remain formidable ch...The surface charge accumulation on polymers often leads to surface flashover.Current solutions are mainly based on the introduction of inorganic fillers.The high-cost process and low compatibility remain formidable challenges.Moreover,existing researches on all-organic insulation focus on capturing electrons,contrary to alleviating charge accumulation.Here,an all-organic modification coating was prepared on polystyrene(PS)with the large-scale atmospheric-pressure plasma,which exhibits outperformed function in mitigating surface charge accumulation.The surface charge dissipation rate and surface conductivity are promoted by about 1.37 and 9.45 times,respectively.Simulation and experimental results show that this all-organic modification coating has a smaller electron affinity potential compared with PS.The decrease of electron affinity potential may result in accelerated surface charge decay of PS,which has never been involved in previous works.Moreover,this coating also has good reliability in a repeated surface flashover.This facile and large-scale approach brings up a novel idea for surface charge regulation and the manufacture of advanced dielectric polymers.展开更多
基金the financial support from National Natural Science Foundation of China(Nos.22078125 and 52004102)Postdoctoral Science Foundation of China(No.2023M741472)。
文摘Surface modification of fabrics is an effective way to endow them with antifouling properties while still maintaining their key advantages such as comfort,softness and stretchability.Herein,an atmospheric pressure dielectric barrier discharge(DBD)plasma method is demonstrated for the processing of silk fabrics using 1H,1H,2H,2H-perfluorodecyltriethoxysilane(PFDS)as the precursor.The results showed the successful grafting of PFDS groups onto the surface of silk fabrics without causing damage.Meanwhile,the gas temperature is rather low during the whole processing procedure,suggesting the non-equilibrium characteristics of DBD plasma.The influence on fabrics of the processing parameters(PFDS concentration,plasma treatment time and plasma discharge power)was systematically investigated.An optimum processing condition was determined to be a PFDS concentration of 8wt%,a plasma processing time of 40 s and a plasma power of 11.87 W.However,with prolonged plasma processing time or enhanced plasma power,the plasma-grafted PFDS films could be degraded.Further study revealed that plasma processing of silk fabrics with PFDS would lead to a change in their chemical composition and surface roughness.As a result,the surface energy of the fabrics was reduced,accompanied by improved water and oil repellency as well as enhanced antifouling performance.Besides,the plasma-grafted PFDS films also had good durability and stability.By extending the method to polyester and wool against different oil-/water-based stains,the DBD plasma surface modification technique demonstrated good versatility in improving the antifouling properties of fabrics.This work provides guidance for the surface modification of fabrics using DBD plasma to confer them with desirable functionalities.
基金supported by Changzhou Basic Research Program(No.CJ20235030)the Research Initiation Fund of Changzhou University(No.ZMF23020057).
文摘Solving intrinsic structural problems such as low conductivity is the main challenge to promote the commercial application of Li_(2)TiSiO_(5).In this study,Li_(2)TiSiO_(5) is synthesized by the sol-gelmethod,and the surface modification of Li_(2)TiSiO_(5) is carried out at different temperatures using low-temperature plasma to enhance its lithium storage performance.The morphological structure and electrochemical tests demonstrate that plasma treatment can improve the degree of agglomeration.The peak position of the plasma-treated Li_(2)TiSiO_(5) is shifted to a lower angle,and the shift angle increases with increasing sputtering power.Li_(2)TiSiO_(5) after 300 W bombardment shows excellent capacity(144.7 mA·hg^(−1)after 500 cycles at 0.1 Ag^(−1))and rate performance(140 mA·hg^(−1)at 5 Ag^(−1)).Electrochemical analysis indicates that excellent electrochemical performance is attributed to the enhancement of electronic and ionic conductivity by plasma bombardment.
基金supported by National Natural Science Foundation of China(Nos.11875121,11575050 and51977057)the Midwest Universities Comprehensive Strength Promotion Project+4 种基金the Natural Science Foundation of Hebei Province,China(Nos.A2019201100,A2020201025)College Hundred Outstanding Innovative Talent Support Program of Hebei Education Bureau(No.SLRC2017021)Post-graduate’s Innovation Fund Project of Hebei Province(Nos.CXZZBS2019023,CXZZBS2019029)the Natural Science Interdisciplinary Research Program of Hebei University(No.DXK201908)Post-graduate’s Innovation Fund Project of Hebei University(No.HBU2021bs011)。
文摘An atmospheric pressure argon plasma brush with air addition is employed to treat polyethylene terephthalate(PET)surface in order to improve its hydrophilicity.Results indicate that the plasma plume generated by the plasma brush presents periodically pulsed current despite a direct current voltage is applied.Voltage-current curve reveals that there is a transition from a Townsend discharge regime to a glow one during one discharge period.Optical emission spectrum indicates that more oxygen atoms are produced in the plume with increasing air content,which leads to the better hydrophilicity of PET surface after plasma treatment.Besides,an aging behavior is also observed.The hydrophilicity improvement is attributed to the production of oxygen functional groups,which increase in number with increasing air content.Moreover,some grain-like structures are observed on the treated PET surface,and its mean roughness increases with increasing air content.These results are of great importance for the hydrophilicity improvement of PET surface with a large scale.
文摘The aging effects of the contact angle and surface energy on polyethylene terephthalate (PET) have been investigated with surface modification by water vapor plasma. The experimental results show that the contact angle of water and PET decreases obviously and surface energy increases. However, with the increase of the aging time, the contact angle and surface energy change back gradually to original state.
基金supported by Liaoning BaiQianWan Talents Program of China (No. 2008921028)Doctoral Fund of Ministry of Education of China (No. 200801451082)
文摘In this study, compounded surface modification technology-high current pulsed electron beam （HCPEB） ＋ micro-plasma oxidation （MPO） was applied to treat ZK60 Mg alloys. The characteristics of the microstructure of ZK60 Mg alloy after single MPO and HCPEB＋MPO compounded treatment were investigated by SEM. The results showed that the density of the ceramic layer of HCPEB＋MPO-treated ZK60 Mg alloy was improved and defects were reduced compared to that under MPO treatment alone. Surface modified layer of ZK60 Mg alloys treated by HCPEB＋MPO was divided into three zones, namely the top loose ceramic zone, middle compact zone and inside HCPEB-induced melted zone. Corrosion resistance of ZK60 Mg alloy before and after the compounded surface modification was measured in a solution of 3.5% NaCl by potentiodynamic polarization curves. It was found that the corrosion current density of ZK60 Mg alloys could be reduced by about three orders of magnitude, from 311μA/cm^2 of the original sample to 0.2μA/cm^2 of the HCPEB＋MPO-treated sample. This indicates the great application potential of the HCPEB＋MPO compounded surface modification technology in improving the corrosion resistance of ZK60 Mg alloys in the future.
基金supported by the Chung-Ang University Research Grants in 2021the National Research Foundation(NRF)of Korea(No.2020R1G1A1102692)。
文摘Indium gallium tin oxide(IGTO)thin films have the potential for high mobility and lowtemperature processing,which makes them suitable for applications such as display backplanes and high-voltage switching devices.However,very few studies have investigated the plasmaetching characteristics of IGTO and changes in its properties after etching.In this study,the etching characteristics of IGTO were investigated using Cl_(2)/Ar plasma,and changes in surface properties were analyzed.Results showed that the etch rate increased with an increase in the proportion of Cl_(2),with the highest etch rate observed at 69 nm min^(-1)in pure Cl_(2)plasma with a gas flow rate of 100 sccm.Furthermore,increased radio-frequency power caused a rise in the etch rate,while a process pressure of 15 m Torr was optimal.The primary etching mechanism for IGTO thin films under Cl_(2)plasma was a chemical reaction,and an increased work function indicated the occurrence of defects on the surface.In addition,the etching process reduced the surface roughness of Cl_(2)-containing plasma,whereas the etching process in pure Ar plasma increased surface roughness.This study contributes to a better understanding of the plasmaetching characteristics of IGTO and changes in its properties after etching,providing valuable insights for IGTO-based applications.
基金supported by National Natural Science Foundation of China(Nos.50725519,51271048,51321004)
文摘The inner surface modification process by plasma-based low-energy ion implantation（PBLEII）with an electron cyclotron resonance（ECR）microwave plasma source located at the central axis of a cylindrical tube is modeled to optimize the low-energy ion implantation parameters for industrial applications.In this paper,a magnetized plasma diffusion fluid model has been established to describe the plasma nonuniformity caused by plasma diffusion under an axial magnetic field during the pulse-off time of low pulsed negative bias.Using this plasma density distribution as the initial condition,a sheath collisional fluid model is built up to describe the sheath evolution and ion implantation during the pulse-on time.The plasma nonuniformity at the end of the pulse-off time is more apparent along the radial direction compared with that in the axial direction due to the geometry of the linear plasma source in the center and the difference between perpendicular and parallel plasma diffusion coefficients with respect to the magnetic field.The normalized nitrogen plasma densities on the inner and outer surfaces of the tube are observed to be about 0.39 and 0.24,respectively,of which the value is 1 at the central plasma source.After a 5μs pulse-on time,in the area less than 2 cm from the end of the tube,the nitrogen ion implantation energy decreases from 1.5 keV to 1.3 keV and the ion implantation angle increases from several degrees to more than 40°;both variations reduce the nitrogen ion implantation depth.However,the nitrogen ion implantation dose peaks of about 2×10^（10）-7×10^（10）ions/cm^2 in this area are 2-4 times higher than that of 1.18×10^（10）ions/cm^2 and 1.63×10^（10）ions/cm^2 on the inner and outer surfaces of the tube.The sufficient ion implantation dose ensures an acceptable modification effect near the end of the tube under the low energy and large angle conditions for nitrogen ion implantation,because the modification effect is mainly determined by the ion implantation dose,just as the mass transfer process in PBLEII is dominated by low-energy ion implantation and thermal diffusion.Therefore,a comparatively uniform surface modification by the low-energy nitrogen ion implantation is achieved along the cylindrical tube on both the inner and outer surfaces.
文摘Cold plasma techniques were used to treat the surface of Kevlar-49 fibers. The dynamic parameters of wetting, contact-angles and surface energy of the fiber before and alter the treatment were compared to see the changes in the wetting property. ESCA and electron spin resonance were utilized to examine the chemical composition and the attached free radicals of the fiber surface. The results, together with changes in the magnitude of the contact-angle and the number of free radicals with time after the plasma treatment do not show any ageing effect. Single filament test revealed that the tensile strength was not impaired but even improved somewhat after the plasma treatment. The experiment shows that the interlaminar shear strength of Kevlar fiber reinforced epoxy resin compo- site is increased for more than 60％% after the treatment.
基金Tenaga Nasional Berhad (Malaysia) for funding this research (TNBR/SF 240/2016)
文摘The effects of non-thermal plasma （NTP） treatment on biomass in the form of pulverized palmbased empty fruit bunches （EFB） are investigated. Specifically, this study investigates the effects of NTP treatment on the surface reactivity, morphology, oxygen-to-carbon （O/C） ratio of the EFB at varying treatment times. The surface reactivity is determined by the reaction of antioxidant functional groups or reactive species with 2,2-diphenyl-l-picrylhydrazyl （DPPH）. By measuring the concentration of the DPPH with a spectrophotometer, the change in the amount of antioxidant functional groups can be measured to determine the surface reactivity. The reactions of the various lignin components in the EFB with respect to the NTP treatment are discussed by qualitatively assessing the changes in the Fourier transform infrared （FTIR） spectra. The surface morphology is examined by a scanning electron microscope. To determine the amount of oxygen deposited on the EFB by the air-based NTP treatment, the oxygen and carbon contents are measured by an energy dispersive x-ray detector to determine the O/C ratio. The results show that the NTP reactor produced reactive species such as atomic oxygen and ozone, increasing the surface reactivity and chemical scavenging rate of the EFB. Consequently, the surface morphology changed, with an observed rougher surface from the images of the EFB samples. The change in the appearance of the surface is accompanied by a high O/C ratio, and is caused by reactions of certain components of lignin due to the NTP treatment, The lignin component that was modified is believed to be syringyl, as the syringyl portion in the lignin of EFBs is higher compared to the other components. Syringyl components are detected in the range of F-FIR wavenumbers of 1109-1363 cm-1. With increasing NTP treatment times, the absorbance （of the peaks in the PTIR spectra） for syringyl related C-H and lignin associated C=C bonds decreases as the syringyl decomposes. The resulting release of carboxyl compounds increases the absorbance for the carbonyl C=O group. The results show that NTP treatment is able to modify the surface properties of EFB, and that the surface reactivity can be increased to improve their conversion and processing efficiencies.
文摘The surface modification of nanometer carbon material has been studied by using an Induced Dielectric Barrier Discharge Plasma device (IDBD). The experimental results show that with different work gases and different discharge conditions, the surface behaviors of carbon black can be changed according to needs, including the use of different functional groups and the change of the surface roughness of carbon particles etc., which increased the grinding and dispersion abilities in binder.
基金supported by National Natural Science Foundation of China(No.21077084)the Foundational Research Fund of Xi'an Jiaotong University(No.08143023)
文摘Using argon as the work gas, the effects and mechanisms of poly（tetrafluoroethylene） （PTFE） film surface modification were investigated in a low pressure plasma reactor. Results show that higher hydrophilicity with little degradation, in terms of the scanning electron microscopy （SEM）, was obtained after treatment, especially when the sample was placed in the post-discharge area. More polar functional groups and higher surface free energy, especially the polar component, formed on the PTFE surface were responsible for the modification. For the relatively high purity radicals and rare discharge particles in the post-discharge area, the etching was restrained and the introducing reactions were enhanced, and thus, a better modification occurred there.
文摘In this paper, an improved quasi-stable atmospheric pressure dielectric barrier discharge （DBD） plasma source is achieved after carefully controlled discharge voltage and current, discharge power, working gas, treatment period, and gap between the electrodes. This plasma source has been used to modify the surface of Polybutylene Terephthalate （PBT） melt-blown nonwovens and Polyester （PET） fabrics, and the various influences on surface modification and the aging effect of treated polymeric materials have been systematically investigated. In addition, the method of spectrum analysis is also used for diagnosing plasma paramneters such as electron temperature. Experimental results indicate that both the wettablity and permeation of treated PBT melt-blown nonwovens and dyeing ability of treated PET fabrics are certainly improved.
文摘Surfaces of optical elements are deposited by antireflection coatings (ARCs) to decrease the reflection of light. Surface needs treatment before depositing the ARC one of treatment processes by plasma for adhesion improvement and surface hardening. A comparison of RF and DC glow discharges treated CR-39 polymer films gives insight into the mechanism of these surface processes. The surface properties of the plasma-treated samples are examined by microscopy techniques include contact angle measurements, scanning electron microscopy (SEM), atomic force microscopy (AFM), infrared (IR) spectroscopy and refractive index measurements. Results show that the plasma treatment modifies the polymer surface in both composition and morphology. It is found that the surface wettability is enhanced after plasma treatment. It is found that, RF plasma is more effective than DC plasma in CR-39 surface modification, as it implants more oxygen atoms into the surface and makes the contact angle declining to a lower level.
基金supported by China Ministry of Science and Technology (973 project No. 2009CB930000)National Natural Science Foundation of China (Nos. 11032012 and 51173216)+3 种基金Fok Ying Tung Education Foundation (121035)Natural Science Foundation of Chongqing Municipal Government (CSTC2011jjjq10004 and CSTC2012gg-yyjs10023)Fundamental Research Funds for the Central Universities (Nos. CDJXS10232211, CDJZR11230005)the sharing fund of Chongqing University's large-scale equipment (Nos. 2011063046,2011063047)
文摘To reduce Ni ion release and improve biocompatibility of NiTi alloy, the cathodic plasma electrolytic deposition （CPED） technique was used to fabricate ceramic coating onto a NiTi alloy surface. The formation of a coating with a rough and micro-textured surface was confirmed by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy, re- spectively. An inductively coupled plasma mass spectrometry test showed that the formed coating significantly reduced the release of Ni ions from the NiTi alloy in simulated body fluid. The in- fluence of CPED treated NiTi substrates on the biological behaviors of osteoblasts, including cell adhesion, cell viability, and osteogenic differentiation function （alkaline phosphatase）, was inves- tigated in vitro. Immunofluorescence staining of nuclei revealed that the CPED treated NiTi alloy was favorable for cell growth. Osteoblasts on CPED modified NiTi alloy showed greater cell viability than those for the native NiTi substrate after 4 and 7 days cultures. More importantly, osteoblasts cultured onto a modified NiTi sample displayed significantly higher differentiation lev-els of alkaline phosphatase. The results suggested that surface functionalization of NiTi alloy with ceramic coating via the CPED technique was beneficial for cell proliferation and differentiation. The approach presented here is useful for NiTi implants to enhance bone osseointegration and reduce Ni ion release in vitro.
基金supported by Natural Science Foundation of Chongqing (No. 2008AA4029)Scientific Research Training Program of Chongqing University
文摘The hot dipping process of pure aluminum on H13 steel substrates followed by plasma electrolytic oxidation(PEO) was studied to form alumina ceramic coatings for protective purpose.H13 steel bars were first dipped in pure aluminum melts,and then,a reactive iron-aluminum intermetallic layer grew at the interface between the melt and the steel substrate.The reactive layer was mainly composed of intermetallic Fe-Al(Fe_2Al_5);the thickness of aluminum layer and Fe-Al intermetallic layer were mainly influenced by dipping time(1.5～12.0 min) and dipping temperature(710～760 ℃).After PEO process,uniform Al_2O_3 ceramic coatings were deposited on the surface of aluminized steel.The element distribution,phase composition and morphology of the aluminized layer,and the ceramic coatings were characterized by SEM/EDS and XRD.The distribution of hardness across the composite coating is demonstrated,and the maximum value reaches 1864 HV.The thermal shock resistance of the coated sample is also well improved.
基金supported by National Natural Science Foundation of China(No.51777076)the Self-topic Fund of State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(No.LAPS2019-21)。
文摘In this paper,plasma fluorination is combined with plasma silicon deposition to achieve step gradient modification on an epoxy resin surface.The physicochemical characteristics of samples are investigated and the electrical performances measured.The obtained results show that compared with untreated and single treated samples,the samples treated by step gradient modification significantly improve the flashover performance.According to experiment and simulation,the mechanism explanations are summarized as follows.First,it is found that the step gradient conductivity can effectively optimize the electric field distribution of a needle-needle electrode.Then,step gradient modification suppresses the accumulation of surface charge at the triple junction and makes the charge distribution more uniform.Furthermore,it can accelerate the surface dissipation on a high electrical field region and control the dissipation rate on a low electrical field region.All these results can restrain surface discharge and increase the flashover voltage.The step gradient modification method proposed in this paper provides a new idea for improving the surface insulation performance.
基金supported by National Natural Science Foundation of China(Nos.11775175,U1766218,51827809)Natural Science Research Fund of Higher Education of Anhui Province(No.KJ2020A0246)。
文摘The flashover performance of insulating materials plays an important role in the development of high-voltage insulation systems.In this paper,silicone rubber(SIR)is modified by CF4 radio frequency capacitively coupled plasma(CCP)for the improvement of surface insulation performance.The discharge mode and active particles of CCP are diagnosed by the digital single-lens reflex and the spectrometer.Scanning electron microscopy and x-ray photoelectron spectroscopy are used for the surface physicochemical properties of samples,while the surface charge dissipation,charge accumulation measurement,and flashover test are applied for the surface electrical characteristics.Experimental results show that the fluorocarbon groups can be grafted and the surface roughness increases after plasma treatment.Besides,the surface charge dissipation is decelerated and the positive charge accumulation is inhibited obviously for the treated samples.Furthermore,the surface flashover voltage can be increased by 26.67%after 10 min of treatment.It is considered that strong electron affinity of C–F and increased surface roughness can contribute to deepening surface traps,which not only inhibits the development of secondary electron emission avalanche but also alleviates the surface charge accumulation and finally improves the surface flashover voltage of SIR.
基金supported by the Fundamental Research Funds for the Central Universities (Nos. GK200901023, GK201004001)
文摘Enhancement of the surface hydrophilicity of biodegradable poly （D,L-lactic acid） （PLA） films is studied. The PLA films were treated by nitrogen plasma （PLA-N2） and nitro- gen/hydrogen plasma （PLA-N2/H2）, respectively. The surface properties and microstructure of PLA-N2 and PLA-N2/H2 were studied by static contact angle measurement, surface free energy calculation, X-ray photoelectron spectroscopy （XPS） and atomic force microscopy （AFM）. It is confirmed that the surface hydrophilicity of PLA-N2 and PLA-N2/H2 was higher than that of pristine PLA, and the surface hydrophilicity of PLA-N2 films was better than that of PLA-N2/H2.
文摘In this study, commercial poly vinyl chloride （PVC） films were treated by oxygen and argon plasmas in a cylindrical glass tube which was surrounded by a DC variable magnetic field, with different sample positions in the plasma reactor and also different exposure durations. Effects of the plasma treatment on the hydrophilic properties of the films were studied by mea- suring the water drop contact angle on the surface of the samples. The surface topography of the untreated and plasma treated films was analyzed and compared by atomic force microscopy （AFM）. The optical characteristic changes in treated samples were investigated using reflective spectrophotometry. Also, the chemical changes which appeared on the surface of the samples were investigated using Fourier transform infrared spectroscopy （FTIR）. The results show that the plasma treated PVC becomes more hydrophilic with an enhanced wettability. A sharp de- crease in the water contact angle may also be a consequence of the surface texturization. The aging effect on wettability of the samples was also investigated. The results show that the effect of oxygen plasma on the surface properties of the samples is more pronounced compared with that of argon plasma.
基金the Graduate Student Research Innovation Project of Chongqing(No.CYB22016)National Natural Science Foundation of China(Nos.52237010,52277135,51907011)。
文摘The surface charge accumulation on polymers often leads to surface flashover.Current solutions are mainly based on the introduction of inorganic fillers.The high-cost process and low compatibility remain formidable challenges.Moreover,existing researches on all-organic insulation focus on capturing electrons,contrary to alleviating charge accumulation.Here,an all-organic modification coating was prepared on polystyrene(PS)with the large-scale atmospheric-pressure plasma,which exhibits outperformed function in mitigating surface charge accumulation.The surface charge dissipation rate and surface conductivity are promoted by about 1.37 and 9.45 times,respectively.Simulation and experimental results show that this all-organic modification coating has a smaller electron affinity potential compared with PS.The decrease of electron affinity potential may result in accelerated surface charge decay of PS,which has never been involved in previous works.Moreover,this coating also has good reliability in a repeated surface flashover.This facile and large-scale approach brings up a novel idea for surface charge regulation and the manufacture of advanced dielectric polymers.
