Non-thermal plasma(NTP)is considered to be a promising technology for the removal of volatile organic compounds;however,its application is limited by low CO_(2) selectivity and undesirable by-products.To overcome thes...Non-thermal plasma(NTP)is considered to be a promising technology for the removal of volatile organic compounds;however,its application is limited by low CO_(2) selectivity and undesirable by-products.To overcome these issues,this paper discusses the degradation of chlorobenzene(CB)in systems of NTP coupled with catalysts,and the influence of catalyst locations in the NTP was investigated.In addition,the interaction between plasma and catalyst was also explored.The results indicated that the degradability of CB was remarkably improved through the combination of NTP with catalysts,and the formation of ozone was effectively inhibited.The degradation efficiency increased from 33.9%to 79.6%at 14 kV in the NTPcatalytic system,while the ozone concentration decreased from 437 to 237 mg m^(-3),and the degradation efficiency of in plasma catalysis(IPC)systems was superior to that of the post plasma catalysis system,while the inhibition ability of ozone exhibited an opposing trend.In the IPC system,the degradation efficiency was 87.7%at 14 k V,while the ozone concentration was151 mg m^(-3).Besides,the plasma did not destroy the pore structure and crystal structure of the catalyst,but affected the surface morphology and redox performance of the catalyst.Thus,NTP coupled catalytic system could improve the degradation performance of CB.Furthermore,the plasma discharge characteristics played a major role in the NTP synergistic catalytic degradation of CB.Finally,based on the experiment analysis results,the general reaction mechanism of CB degradation in an IPC reaction system was proposed.展开更多
C1 chemistrymainly involves the catalytic transformation of C1molecules(i.e.,CO,CO2,CH4 and CH3OH),which usually encounters thermodynamic and/or kinetic limitations.To address these limitations,non-thermal plasma(NTP)...C1 chemistrymainly involves the catalytic transformation of C1molecules(i.e.,CO,CO2,CH4 and CH3OH),which usually encounters thermodynamic and/or kinetic limitations.To address these limitations,non-thermal plasma(NTP)activated heterogeneous catalysis offers a number of advantages,such as relatively mild reaction conditions and energy efficiency,in comparison to the conventional thermal catalysis.This review presents the state-of-the-art for the application of NTP-catalysis towards C1 chemistry,including the CO2 hydrogenation,reforming of CH4 and CH3OH,and water-gas shift(WGS)reaction.In the hybrid NTP-catalyst system,the plasma-catalyst interactions aremultifaceted.Accordingly,this reviewalso includes a brief discussion on the fundamental research into themechanisms of NTP activated catalytic C1 chemistry,such as the advanced characterisation methods(e.g.,in situ diffuse reflectance infrared Fourier transform spectroscopy,DRIFTS),temperatureprogrammed plasma surface reaction(TPPSR),kinetic studies.Finally,prospects for the future research on the development of tailor-made catalysts for NTP-catalysis systems(which will enable the further understanding of its mechanism)and the translation of the hybrid technique to practical applications of catalytic C1 chemistry are discussed.展开更多
This review describes the application of non-thermal plasma(NTP) technology for high barrier layer fabrication in packaging area.NTP technology is considered to be the most prospective approaches for the barrier lay...This review describes the application of non-thermal plasma(NTP) technology for high barrier layer fabrication in packaging area.NTP technology is considered to be the most prospective approaches for the barrier layer fabrication over the past decades due to unpollution,high speed,low-costing.The applications of NTP technology have achieved numerous exciting results in high barrier packaging area.Now it seemly demands a detailed review to summarize the past works and direct the future developments.This review focuses on the different NTP resources applied in the high barrier area,the role of plasma surface modification on packaging film surface properties,and the deposition of different barrier coatings based on NTP technology.In particular,this review emphasizes the cutting-edge technologies of NTP on interlayer deposition with organic,inorganic for multilayer barriers fabrication.The future prospects of NTP technology in high barrier film areas are also described.展开更多
In order to investigate the feasibility of sequential removal NO and SO2 using non-thermal plasma and adsorbent simultaneously, the removal of NO and SO2 from dry gas stream (NO/SO2/N2/O2) with very little O2 using ...In order to investigate the feasibility of sequential removal NO and SO2 using non-thermal plasma and adsorbent simultaneously, the removal of NO and SO2 from dry gas stream (NO/SO2/N2/O2) with very little O2 using non-thermal plasma was investigated using a coaxial dielectric barrier discharge. Comparative experiments were carried out in the dry gas stream with and without Ar respectively at O2 concentration of 0.1%. The results showed that NO could be removed remarkably and it would be enhanced in the presence of Ar in the dry gas stream. It seems that SO2 could not be removed unless there is Ar in the dry gas stream. The mechanism of removal of NO and SO2 in the dry gas stream was discussed.展开更多
An experimental system of De-NO with plasma-catalyst(Cu zeolite) was established to investigate the differences between De- NO with plasma-catalyst and De-NO only with plasma, to provide the instruction for selectin...An experimental system of De-NO with plasma-catalyst(Cu zeolite) was established to investigate the differences between De- NO with plasma-catalyst and De-NO only with plasma, to provide the instruction for selecting appropriate catalyst and operating condition, The characteristics of De-NO with plasma and De-NO with plasma-catalyst were investigated comparatively by experiments. The experimental results show that De-NO with plasma-catalyst has high NO removal rate; Cu zeolite is an effective catalyst which can promote NO removal rate in plasma remarkably; De-NO with plasma-catalyst should be operated at low temperature and the temperature has opposite effects on the function of catalvst and plasma; water vapor and O2 can increase the NO removal rate.展开更多
In this work,non-thermal plasma has been applied to treat polyacrylamide(PAM)wastewater.We have investigated the in fluence of the rule of PAM wastewater initial pH,solution concentration and discharge time,discharge ...In this work,non-thermal plasma has been applied to treat polyacrylamide(PAM)wastewater.We have investigated the in fluence of the rule of PAM wastewater initial pH,solution concentration and discharge time,discharge voltage on chemical oxygen demand(COD)degradation rate.At the same time,the effect of pH and discharge time on the viscosity removal rate of PAM solution was also studied.Then,the effect of pH on the viscosity removal rate of 1.0g 1^-1 PAM solution was studied separately.Through orthogonal test,the factors affecting the COD degradation rate of PAM wastewater were determined as follows:discharge time>discharge voltage>solution concentration>wastewater initial pH.1'he COD highest removal rate of PAM wastewater reached 85.74%,when the optimal conditions are as follows:discharge voltage 40 kV,discharge time 5 h,solution concentration 1.0 g 1^-1,pH 1.5.This research provides some basic data and new theoretical basis for PAM wastewater purification.展开更多
An atmospheric non-thermal plasma jet was developed for sterilizing the Staphylococcus aureus (S. aureus). The plasma jet was generated by dielectric barrier discharge (DBD), which was characterized by electrical ...An atmospheric non-thermal plasma jet was developed for sterilizing the Staphylococcus aureus (S. aureus). The plasma jet was generated by dielectric barrier discharge (DBD), which was characterized by electrical and optical diagnostics. The survival curves of the bacteria showed that the plasma jet could effectively inactivate 10 6 cells of S. aureus within 120 seconds and the sterilizing efficiency depended critically on the discharge parameter of the applied voltage. It was further confirmed by scanning electron microscopy (SEM) that the cell morphology was seriously damaged by the plasma treatment. The plasma sterilization mechanism of S. aureus was attributed to the active species of OH, N 2 + and O, which were generated abundantly in the plasma jet and characterized by OES. Our findings suggest a convenient and low-cost way for sterilization and inactivation of bacteria.展开更多
The present study evaluated the effect of non-thermal plasma on skin wound healing in BalB/c mice.Two 6-mm wounds along the both sides of the spine were created on the back of each mouse(n=80) by using a punch biops...The present study evaluated the effect of non-thermal plasma on skin wound healing in BalB/c mice.Two 6-mm wounds along the both sides of the spine were created on the back of each mouse(n=80) by using a punch biopsy.The mice were assigned randomly into two groups,with 40 animals in each group:a non-thermal plasma group in which the mice were treated with the non-thermal plasma;a control group in which the mice were left to heal naturally.Wound healing was evaluated on postoperative days(POD) 4,7,10 and 14(n=5 per group in each POD) by percentage of wound closure.The mice was euthanized on POD 1,4,7,10,14,21,28 and 35(n=1 in each POD).The wounds were removed,routinely fixed,paraffin-embedded,sectioned and HE-stained.A modified scoring system was used to evaluate the wounds.The results showed that acute inflammation peaked on POD 4 in non-thermal plasma group,earlier than in control group in which acute inflammation reached a peak on POD 7,and the acute inflammation scores were much lower in non-thermal group than in control group on POD 7(P0.05).The amount of granular tissue was greater on POD 4 and 7 in non-thermal group than in control group(P0.05).The re-epithelialization score and the neovasularization score were increased significantly in non-thermal group when compared with control group on POD 7 and 10(P0.05 for all).The count of bacterial colonies was 103 CFU/mL on POD 4 and 20 CFU/mL on POD 7,significantly lower than that in control group(109 CFU/mL on POD 4 and 1012 CFU/mL on the POD 7)(P0.05).It was suggested that the non-thermal plasma facilitates the wound healing by suppressing bacterial colo-nization.展开更多
A non-thermal plasma brush is employed to deposit stain-resistant SiO2-like coatings on resin composite fillings and bovine teeth.With post-treating by plasma,the hardness of the coating increases from H to 8H and the...A non-thermal plasma brush is employed to deposit stain-resistant SiO2-like coatings on resin composite fillings and bovine teeth.With post-treating by plasma,the hardness of the coating increases from H to 8H and the water contact angle decreases from 98.8° to 61.7°.The Fourier transform infrared spectroscopy (FTIR) results show that,after plasma post-treating,the Si-O-Si and Si-OH bonds of the coating increase.Scanning electron microscope (SEM) images show the coatings to be uniform,without cracks.The coatings present outstanding performance in a stain resistance test both on resin composite and bovine teeth.Being easy to handle and less time consuming than traditional methods,with a body-friendly temperature and material,this plasma brush provides a promising in-situ coating method on patient teeth in dental clinics.展开更多
Particulate matter(PM)capture tests were carried out on clean diesel particulate filters(DPFs)under different loads(25%,50%,75%and 100%).DPFs were regenerated by a non-thermal plasma(NTP)injection device.Raman spectro...Particulate matter(PM)capture tests were carried out on clean diesel particulate filters(DPFs)under different loads(25%,50%,75%and 100%).DPFs were regenerated by a non-thermal plasma(NTP)injection device.Raman spectroscopy and x-ray photoelectron spectroscopy were used to investigate changes in the microstructure and element occurrence state of the sediment in DPF channel before and after regeneration.The order of the PM samples decreased before NTP treatment as the load increased;the amorphous carbon content was high,and the oxidationactivity was higher.After NTP treatment,the carbon atoms at the edge of the microcrystalline structure in the ash-PM samples were oxidized,and the structure was reorganized;in addition,the amorphous carbon content decreased,and the structure was more diversified.Before NTP,the C element of PM samples was the main component,and the content of the O element was relatively low.The C element occurred in the form of C–C,C–OH,and O–C=O functional groups,and O atoms were mainly combined with C–O.After NTP,the content of Na,P,S,Ca,and other inorganic elements in ash-PM samples was prominent because C atoms were removed by NTP active substances.There were two forms of S element occurrence(SO42-and SO32-);the proportion of SO42-was approximately 40%,and the proportion of SO32-was approximately60%.Study of the microstructure and element occurrence of the residues in the DPF channels improved our understanding of the mechanism of the low-temperature regeneration of DPFfrom NTP.展开更多
The non-thermal plasma created by high voltage pulsed power supply can be used to remove sulfur dioxide in the air, but how to increase the removing efficiency is not clear. It is novel to apply the magnetic field in ...The non-thermal plasma created by high voltage pulsed power supply can be used to remove sulfur dioxide in the air, but how to increase the removing efficiency is not clear. It is novel to apply the magnetic field in removing SO2 as discussed in this paper. The mechanisms of removing sulfur dioxide by non-thermal plasma along with the application of the magnetic field are analyzed, and the related factors affecting the removal efficiency, such as the magnitude of pulsed voltage, the polarity of the pulse, the layout of the discharge electrode, especially the magnetic field are experimentally investigated. It can be concluded that the purification efficiency is improved significantly by applying the magnetic field.展开更多
The kinetics mechanism of the dissociation reactions in a NO/SO2/N2/O2 system was investigated in consideration of energetic electrons' impacts on a non-thermal plasma. A model was derived from the Boltzmann equation...The kinetics mechanism of the dissociation reactions in a NO/SO2/N2/O2 system was investigated in consideration of energetic electrons' impacts on a non-thermal plasma. A model was derived from the Boltzmann equation and molecule collision theory to predict the dissociation reaction rate coefficients. Upon comparison with available literature, the model was confirmed to be acceptably accurate in general. Several reaction rate coefficients of the NO/SO2/N2/O2 dissociation system were derived according to the Arrhenius formula. The activation energies of each plasma reaction were calculated by quantum chemistry methods. The relation between the dissociation reaction rate coefficient and electron temperature was established to describe the importance of each reaction and to predict relevant processes of gaseous chemical reactions. The sensitivity of the mechanism of NO/SO2/N2/O2 dissociation reaction in a non-thermal plasma was also analysed.展开更多
Improvement of polytetrafluoroethylene surface energy by non-thermal plasma treatment is presented, using a nanosecond-positive-edge repetitive pulsed dielectric barrier discharge generator in atmospheric air. The ele...Improvement of polytetrafluoroethylene surface energy by non-thermal plasma treatment is presented, using a nanosecond-positive-edge repetitive pulsed dielectric barrier discharge generator in atmospheric air. The electrical parameters including discharging power, peak and density of micro-discharge current were calculated, and the electron energy was estimated. Surface treatment experiments of polytetrafluoroethylene films were conducted for both different applied voltages and different treating durations. Results show that the surface energy of polytetrafluoroethylene film could be improved to 40 mJ/m2 or more by plasma treatment. Surface roughness measurement and surface X-ray photoelectron spectroscopy analysis indicate that there are chemical etching and implantation of polar oxygen groups in the sample surface treating process, resulting in the improvement of the sample surface energy. Compared with an AC source of 50 Hz, the dielectric barrier discharges generated by a repetitive pulsed source could provide higher peak power, lower mean power, larger micro-discharge current density and higher electron energy. Therefore, with the same applied peak voltage and treating duration, the improvement of polytetrafluoroethylene surface energy using repetitive pulsed plasma is more effective, and the plasma treatment process based on repetitive pulsed dielectric barrier discharges in air is thus feasible and applicable.展开更多
Increasing concern with regard to food safety in the presence of pesticide residues(PRs) on the surface of agricultural products has resulted in the rapid development of practical degrading technologies for correspond...Increasing concern with regard to food safety in the presence of pesticide residues(PRs) on the surface of agricultural products has resulted in the rapid development of practical degrading technologies for corresponding PRs. In this paper, an unconventional method of degrading pesticides, non-thermal atmospheric plasma(NTAP), was proposed to degrade the avermectin(AVM) in aqueous solution. Optical emission spectroscopy shows that NTAP, consisting of filamentary streamers, contains a variety of reactive oxygen species(ROS) that may interact with AVM. The high-performance liquid chromatography(HPLC)-MS/MS results indicate that the efficiency of AVM degradation seriously depends on multiple operation parameters of the NTAP,including the applied voltage, treatment time and gas flow rate. The maximum degradation rate of AVM was observed to be 97.47% after 240 s exposure under NTAP with an applied voltage of 18 kV and gas flow rate of 1 l min-1. Molecular dynamics simulation based on a reactive force field for the interaction between O(ground state atomic oxygen) and AVM was performed to analyze the underpinning mechanisms. The simulation result shows the possible pathways of the NTAPgenerated O degrading AVM by destroying the glycosyl group or fracturing the ester group.展开更多
Non-thermal C/H/Ar plasmas are widely applied to carbonaceous material production and processing.In this work,plasma parameters and gaseous species of the atmospheric non-thermal C/H/Ar plasmas produced by an atmosphe...Non-thermal C/H/Ar plasmas are widely applied to carbonaceous material production and processing.In this work,plasma parameters and gaseous species of the atmospheric non-thermal C/H/Ar plasmas produced by an atmospheric-pressure DC arc discharge generator in CH_4/Ar were investigated.The voltage-current characteristics were measured for different CH_4/Ar ratios.Optical emission spectroscopy was employed to analyze the electron excitation temperature,gas temperature and electron density under various discharge conditions.The hydrocarbon molecules produced in the CH4/Ar plasmas were detected with photoionization mass spectrometry.The optical spectral results demonstrated that the electron excitation temperature was 0.4-1 eV,the gas temperature was 2800-4200 K and the electron density was in the range of(5-20)×10^15 cm^-3.The mass spectrum indicated that a variety of unsaturated hydrocarbons(C2H4,C3H6,C6H6,etc.) and several highly unsaturated hydrocarbons(C4H2,C5H6,etc.) were produced in the non-thermal arc plasmas.展开更多
In this paper,the characteristics of detonation combustion ignited by AC-driven non-thermal plasma and spark plug in air/acetylene mixture have been compared in a doubletube experiment system.The two tubes had the sam...In this paper,the characteristics of detonation combustion ignited by AC-driven non-thermal plasma and spark plug in air/acetylene mixture have been compared in a doubletube experiment system.The two tubes had the same structure,and their closed ends were installed with a plasma generator and a spark plug,respectively.The propagation characteristics of the flame were measured by pressure sensors and ion probes.The experiment results show that,compared with a spark plug,the non-thermal plasma obviously broadened the range of equivalence ratio when the detonation wave could develop successfully,it also heightened the pressure value of detonation wave.Meanwhile,the detonation wave development time and the entire flame propagation time were reduced by half.All of these advantages benefited from the larger ignition volume when a non-thermal plasma was applied.展开更多
Ion-acoustic solitary (IAS) waves in electron-positron-ion (e-p-i) plasma have been of interest to many researchers probably due to their relevance in understanding the Universe. However, the study of non-linear ion-a...Ion-acoustic solitary (IAS) waves in electron-positron-ion (e-p-i) plasma have been of interest to many researchers probably due to their relevance in understanding the Universe. However, the study of non-linear ion-acoustic waves in e-p-i plasma with non-thermal electrons has not been adequately studied. A theoretical investigation on non-linear IAS waves in e-p-i plasma comprising of warm inertial adiabatic fluid ions and electrons that are kappa distributed, and Boltzman distributed positron is presented here using the Sagdeev potential technique. It was found that existence domains of finite amplitude IAS waves were confined within the limits of minimum and maximum Mach numbers with varying k values. For lower values of k, the amplitude of the solitary electrostatic potential structures increased as the width decreased, while for high values, the potential amplitude decreased as the width of the solitary structure increased.展开更多
In this paper, NiAl layered double hydroxides (NiAl-LDHs) has been modified by non-thermal plasma (NTP) to enhance the fluoride removal capacity of materials. The samples were characterized by X-ray diffraction, Fouri...In this paper, NiAl layered double hydroxides (NiAl-LDHs) has been modified by non-thermal plasma (NTP) to enhance the fluoride removal capacity of materials. The samples were characterized by X-ray diffraction, Fourier transform infrared spectrometer (FTIR), Thermogravimetric differential thermal analyzer (TG-DTA) and N2 adsorption-desorption. Effects of pH, co-existing anions, temperature and kinetics on F﹣ adsorption were investigated. The results showed that pH affects the adsorbent surface charge. The effective pH range for F﹣ removal was between 4.5 and 10. Lower pH potentially causes dissolution of NiAl-LDHs. The negligible interference of coexisting ions such as makes the NiAl-LDHs a promising sorbent for fluoride polluted water treatment.展开更多
Homogeneous gold nanoparticles were synthesized under atmospheric pressure using a nonthermal helium plasma jet in a single-step process.A current power supply was used to generate the plasma discharge rich in diverse...Homogeneous gold nanoparticles were synthesized under atmospheric pressure using a nonthermal helium plasma jet in a single-step process.A current power supply was used to generate the plasma discharge rich in diverse reactive species.These species induce rapid chemical reactions responsible for the reduction of the gold salts upon contact with the liquid solution.In this study,spherical and monodispersed gold nanoparticles were obtained within 5 min of plasma exposure using a solution containing gold(Ⅲ)chloride hydrate(HAuCl_(4))as a precursor and polyvinylpyrrolidone(PVP)as a capping agent to inhibit agglomerations.The formation of these metal nanoparticles was initially perceptible through a visible change in the sample's color,transitioning from light yellow to a red/pink color.This was subsequently corroborated by UVvis spectroscopy,which revealed an optical absorption in the 520-550 nm range for Au NPs,corresponding to the surface plasmon resonance(SPR)band.An investigation into the impact of various parameters,including plasma discharge duration,precursor and capping agent concentrations,was carried out to optimize conditions for the formation of well-separated,spherical gold nanoparticles.Dynamic light scattering(DLS)was used to measure the size of these nanoparticles,transmission electron microscopy(TEM)was used to observe their morphology and X-ray diffraction(XRD)was also employed to determine their crystallographic structure.The results confirm that homogeneous spherical gold nanoparticles with an average diameter of 13 nm can be easily synthesized through a rapid,straightforward,and environmentally friendly approach utilizing a helium atmospheric pressure plasma.展开更多
Non-thermal plasma(NTP)is regarded as a potential application for environmental pollution control due to its ability to remove pollutants.As a major precursor of dioxins,the influence of the parameters of 1,2,4-trichl...Non-thermal plasma(NTP)is regarded as a potential application for environmental pollution control due to its ability to remove pollutants.As a major precursor of dioxins,the influence of the parameters of 1,2,4-trichlorobenzene(TCB)decomposition using NTP technology was investigated through a series of experiments,including voltage,frequency,water content,initial concentration,flow rate,and oxygen content.The experimental results show that the energy injected into the NTP system has a positive correlation to voltage and frequency.Oxygen has the greatest influence on TCB decomposition.The optimal reaction condition was at 15 kV,1000 Hz,an initial concentration of 20 mg m^?3,a flow rate of 2 l min^?1,H2O at 4%,and O2 at 0%.Under this condition,the TCB removal efficiency could reach 92%.According to the generated product backstepping,the hydroxyl radical(·OH)plays an important role in TCB decomposition due to its strong oxidation,which participates in the dechlorination and oxidation reactions as free radicals,and the possible decomposition pathway of TCB by NTP is inferred from the identified byproducts.It is of great significance to investigate the influence of the parameters of TCB decomposition using NTP technology in order to provide references for industrial application.展开更多
基金supported by the National Key Research and Development Program of China(No.2018YFC1903100)Beijing Municipal Science and Technology Project Program(No.Z191100009119002)the State Environmental Protection Key Laboratory of Odor Pollution Control(No.20210504)。
文摘Non-thermal plasma(NTP)is considered to be a promising technology for the removal of volatile organic compounds;however,its application is limited by low CO_(2) selectivity and undesirable by-products.To overcome these issues,this paper discusses the degradation of chlorobenzene(CB)in systems of NTP coupled with catalysts,and the influence of catalyst locations in the NTP was investigated.In addition,the interaction between plasma and catalyst was also explored.The results indicated that the degradability of CB was remarkably improved through the combination of NTP with catalysts,and the formation of ozone was effectively inhibited.The degradation efficiency increased from 33.9%to 79.6%at 14 kV in the NTPcatalytic system,while the ozone concentration decreased from 437 to 237 mg m^(-3),and the degradation efficiency of in plasma catalysis(IPC)systems was superior to that of the post plasma catalysis system,while the inhibition ability of ozone exhibited an opposing trend.In the IPC system,the degradation efficiency was 87.7%at 14 k V,while the ozone concentration was151 mg m^(-3).Besides,the plasma did not destroy the pore structure and crystal structure of the catalyst,but affected the surface morphology and redox performance of the catalyst.Thus,NTP coupled catalytic system could improve the degradation performance of CB.Furthermore,the plasma discharge characteristics played a major role in the NTP synergistic catalytic degradation of CB.Finally,based on the experiment analysis results,the general reaction mechanism of CB degradation in an IPC reaction system was proposed.
基金the financial support from the Jiangsu Specially-Appointed Professors Program and the European Commission under the Marie Skłodowska-Curie Individual Fellowship(H2020-MSCA-IFNTPleasure-748196).
文摘C1 chemistrymainly involves the catalytic transformation of C1molecules(i.e.,CO,CO2,CH4 and CH3OH),which usually encounters thermodynamic and/or kinetic limitations.To address these limitations,non-thermal plasma(NTP)activated heterogeneous catalysis offers a number of advantages,such as relatively mild reaction conditions and energy efficiency,in comparison to the conventional thermal catalysis.This review presents the state-of-the-art for the application of NTP-catalysis towards C1 chemistry,including the CO2 hydrogenation,reforming of CH4 and CH3OH,and water-gas shift(WGS)reaction.In the hybrid NTP-catalyst system,the plasma-catalyst interactions aremultifaceted.Accordingly,this reviewalso includes a brief discussion on the fundamental research into themechanisms of NTP activated catalytic C1 chemistry,such as the advanced characterisation methods(e.g.,in situ diffuse reflectance infrared Fourier transform spectroscopy,DRIFTS),temperatureprogrammed plasma surface reaction(TPPSR),kinetic studies.Finally,prospects for the future research on the development of tailor-made catalysts for NTP-catalysis systems(which will enable the further understanding of its mechanism)and the translation of the hybrid technique to practical applications of catalytic C1 chemistry are discussed.
基金financially supported by National Natural Science Foundation of China (Nos.11505013,11775028)Beijing Municipal Excellent Talent Training Foundation (No.2016000026833ZK12)+2 种基金Science and Technology Innovational Serviceability Building Project of Beijing Municipal Education Commission (No.PXM2017_014223_000066)Excellent Talent Selection and Training Project of BIGC of China (No.04190117004/026)Institute level project of BIGC of China (No.Eb201502)
文摘This review describes the application of non-thermal plasma(NTP) technology for high barrier layer fabrication in packaging area.NTP technology is considered to be the most prospective approaches for the barrier layer fabrication over the past decades due to unpollution,high speed,low-costing.The applications of NTP technology have achieved numerous exciting results in high barrier packaging area.Now it seemly demands a detailed review to summarize the past works and direct the future developments.This review focuses on the different NTP resources applied in the high barrier area,the role of plasma surface modification on packaging film surface properties,and the deposition of different barrier coatings based on NTP technology.In particular,this review emphasizes the cutting-edge technologies of NTP on interlayer deposition with organic,inorganic for multilayer barriers fabrication.The future prospects of NTP technology in high barrier film areas are also described.
基金Project supported by the National Natural Sciences Foundation of China(No.50576037)Natural Science Foundation of Jiangsu Province(No.BK2006198)
文摘In order to investigate the feasibility of sequential removal NO and SO2 using non-thermal plasma and adsorbent simultaneously, the removal of NO and SO2 from dry gas stream (NO/SO2/N2/O2) with very little O2 using non-thermal plasma was investigated using a coaxial dielectric barrier discharge. Comparative experiments were carried out in the dry gas stream with and without Ar respectively at O2 concentration of 0.1%. The results showed that NO could be removed remarkably and it would be enhanced in the presence of Ar in the dry gas stream. It seems that SO2 could not be removed unless there is Ar in the dry gas stream. The mechanism of removal of NO and SO2 in the dry gas stream was discussed.
基金The National Basic Research Program(973) of China(G1999022209)
文摘An experimental system of De-NO with plasma-catalyst(Cu zeolite) was established to investigate the differences between De- NO with plasma-catalyst and De-NO only with plasma, to provide the instruction for selecting appropriate catalyst and operating condition, The characteristics of De-NO with plasma and De-NO with plasma-catalyst were investigated comparatively by experiments. The experimental results show that De-NO with plasma-catalyst has high NO removal rate; Cu zeolite is an effective catalyst which can promote NO removal rate in plasma remarkably; De-NO with plasma-catalyst should be operated at low temperature and the temperature has opposite effects on the function of catalvst and plasma; water vapor and O2 can increase the NO removal rate.
基金supported by Anhui University of Science and Technology Youth Fund(No.QN201415)Anhui Province Science and Technology Key Project(No.1301042130)College Students’ Innovation and Entrepreneurship Training Program(No.201810361079)
文摘In this work,non-thermal plasma has been applied to treat polyacrylamide(PAM)wastewater.We have investigated the in fluence of the rule of PAM wastewater initial pH,solution concentration and discharge time,discharge voltage on chemical oxygen demand(COD)degradation rate.At the same time,the effect of pH and discharge time on the viscosity removal rate of PAM solution was also studied.Then,the effect of pH on the viscosity removal rate of 1.0g 1^-1 PAM solution was studied separately.Through orthogonal test,the factors affecting the COD degradation rate of PAM wastewater were determined as follows:discharge time>discharge voltage>solution concentration>wastewater initial pH.1'he COD highest removal rate of PAM wastewater reached 85.74%,when the optimal conditions are as follows:discharge voltage 40 kV,discharge time 5 h,solution concentration 1.0 g 1^-1,pH 1.5.This research provides some basic data and new theoretical basis for PAM wastewater purification.
基金supported by National Natural Science Foundation of China (Nos.10835004 and 10905010)the New Century Excellent Talents in University of China (No.NCET-08-0760)
文摘An atmospheric non-thermal plasma jet was developed for sterilizing the Staphylococcus aureus (S. aureus). The plasma jet was generated by dielectric barrier discharge (DBD), which was characterized by electrical and optical diagnostics. The survival curves of the bacteria showed that the plasma jet could effectively inactivate 10 6 cells of S. aureus within 120 seconds and the sterilizing efficiency depended critically on the discharge parameter of the applied voltage. It was further confirmed by scanning electron microscopy (SEM) that the cell morphology was seriously damaged by the plasma treatment. The plasma sterilization mechanism of S. aureus was attributed to the active species of OH, N 2 + and O, which were generated abundantly in the plasma jet and characterized by OES. Our findings suggest a convenient and low-cost way for sterilization and inactivation of bacteria.
基金supported by grants from the National Natural Sciences Foundation of China(Nos.10875048,30700717)
文摘The present study evaluated the effect of non-thermal plasma on skin wound healing in BalB/c mice.Two 6-mm wounds along the both sides of the spine were created on the back of each mouse(n=80) by using a punch biopsy.The mice were assigned randomly into two groups,with 40 animals in each group:a non-thermal plasma group in which the mice were treated with the non-thermal plasma;a control group in which the mice were left to heal naturally.Wound healing was evaluated on postoperative days(POD) 4,7,10 and 14(n=5 per group in each POD) by percentage of wound closure.The mice was euthanized on POD 1,4,7,10,14,21,28 and 35(n=1 in each POD).The wounds were removed,routinely fixed,paraffin-embedded,sectioned and HE-stained.A modified scoring system was used to evaluate the wounds.The results showed that acute inflammation peaked on POD 4 in non-thermal plasma group,earlier than in control group in which acute inflammation reached a peak on POD 7,and the acute inflammation scores were much lower in non-thermal group than in control group on POD 7(P0.05).The amount of granular tissue was greater on POD 4 and 7 in non-thermal group than in control group(P0.05).The re-epithelialization score and the neovasularization score were increased significantly in non-thermal group when compared with control group on POD 7 and 10(P0.05 for all).The count of bacterial colonies was 103 CFU/mL on POD 4 and 20 CFU/mL on POD 7,significantly lower than that in control group(109 CFU/mL on POD 4 and 1012 CFU/mL on the POD 7)(P0.05).It was suggested that the non-thermal plasma facilitates the wound healing by suppressing bacterial colo-nization.
文摘A non-thermal plasma brush is employed to deposit stain-resistant SiO2-like coatings on resin composite fillings and bovine teeth.With post-treating by plasma,the hardness of the coating increases from H to 8H and the water contact angle decreases from 98.8° to 61.7°.The Fourier transform infrared spectroscopy (FTIR) results show that,after plasma post-treating,the Si-O-Si and Si-OH bonds of the coating increase.Scanning electron microscope (SEM) images show the coatings to be uniform,without cracks.The coatings present outstanding performance in a stain resistance test both on resin composite and bovine teeth.Being easy to handle and less time consuming than traditional methods,with a body-friendly temperature and material,this plasma brush provides a promising in-situ coating method on patient teeth in dental clinics.
基金supported by National Natural Science Foundation of China(No.51806085)China Postdoctoral Science Foundation(No.2018M642175)+2 种基金Jiangsu Planned Projects for Postdoctoral Research Fund(No.2018K101C)Open Research Subject of Key Laboratory of automotive measurement,control and safety(Xihua University)(No.QCCK2021-007)Graduate Student Innovation Fund Project of Jiangsu Province(No.KYCX213354)。
文摘Particulate matter(PM)capture tests were carried out on clean diesel particulate filters(DPFs)under different loads(25%,50%,75%and 100%).DPFs were regenerated by a non-thermal plasma(NTP)injection device.Raman spectroscopy and x-ray photoelectron spectroscopy were used to investigate changes in the microstructure and element occurrence state of the sediment in DPF channel before and after regeneration.The order of the PM samples decreased before NTP treatment as the load increased;the amorphous carbon content was high,and the oxidationactivity was higher.After NTP treatment,the carbon atoms at the edge of the microcrystalline structure in the ash-PM samples were oxidized,and the structure was reorganized;in addition,the amorphous carbon content decreased,and the structure was more diversified.Before NTP,the C element of PM samples was the main component,and the content of the O element was relatively low.The C element occurred in the form of C–C,C–OH,and O–C=O functional groups,and O atoms were mainly combined with C–O.After NTP,the content of Na,P,S,Ca,and other inorganic elements in ash-PM samples was prominent because C atoms were removed by NTP active substances.There were two forms of S element occurrence(SO42-and SO32-);the proportion of SO42-was approximately 40%,and the proportion of SO32-was approximately60%.Study of the microstructure and element occurrence of the residues in the DPF channels improved our understanding of the mechanism of the low-temperature regeneration of DPFfrom NTP.
基金The project supported by the Teaching and Research Award Program for Outstanding Young Teachers in Higher EducationInstitutions under the MOE, China (No. 123-2002)
文摘The non-thermal plasma created by high voltage pulsed power supply can be used to remove sulfur dioxide in the air, but how to increase the removing efficiency is not clear. It is novel to apply the magnetic field in removing SO2 as discussed in this paper. The mechanisms of removing sulfur dioxide by non-thermal plasma along with the application of the magnetic field are analyzed, and the related factors affecting the removal efficiency, such as the magnitude of pulsed voltage, the polarity of the pulse, the layout of the discharge electrode, especially the magnetic field are experimentally investigated. It can be concluded that the purification efficiency is improved significantly by applying the magnetic field.
文摘The kinetics mechanism of the dissociation reactions in a NO/SO2/N2/O2 system was investigated in consideration of energetic electrons' impacts on a non-thermal plasma. A model was derived from the Boltzmann equation and molecule collision theory to predict the dissociation reaction rate coefficients. Upon comparison with available literature, the model was confirmed to be acceptably accurate in general. Several reaction rate coefficients of the NO/SO2/N2/O2 dissociation system were derived according to the Arrhenius formula. The activation energies of each plasma reaction were calculated by quantum chemistry methods. The relation between the dissociation reaction rate coefficient and electron temperature was established to describe the importance of each reaction and to predict relevant processes of gaseous chemical reactions. The sensitivity of the mechanism of NO/SO2/N2/O2 dissociation reaction in a non-thermal plasma was also analysed.
基金supported by the Science Foundation for the Excellent Doctor Dissertations of Ministry of Education of China (No. 200338)the State Natural Sciences Foundation of China (Nos. 50937004, 50777051)
文摘Improvement of polytetrafluoroethylene surface energy by non-thermal plasma treatment is presented, using a nanosecond-positive-edge repetitive pulsed dielectric barrier discharge generator in atmospheric air. The electrical parameters including discharging power, peak and density of micro-discharge current were calculated, and the electron energy was estimated. Surface treatment experiments of polytetrafluoroethylene films were conducted for both different applied voltages and different treating durations. Results show that the surface energy of polytetrafluoroethylene film could be improved to 40 mJ/m2 or more by plasma treatment. Surface roughness measurement and surface X-ray photoelectron spectroscopy analysis indicate that there are chemical etching and implantation of polar oxygen groups in the sample surface treating process, resulting in the improvement of the sample surface energy. Compared with an AC source of 50 Hz, the dielectric barrier discharges generated by a repetitive pulsed source could provide higher peak power, lower mean power, larger micro-discharge current density and higher electron energy. Therefore, with the same applied peak voltage and treating duration, the improvement of polytetrafluoroethylene surface energy using repetitive pulsed plasma is more effective, and the plasma treatment process based on repetitive pulsed dielectric barrier discharges in air is thus feasible and applicable.
基金National Natural Science Foundation of China (Grant Nos. 11675095 and 52077128)the Fundamental Research Funds of Shandong University (Grant No. 2017JC017) for supporting the research。
文摘Increasing concern with regard to food safety in the presence of pesticide residues(PRs) on the surface of agricultural products has resulted in the rapid development of practical degrading technologies for corresponding PRs. In this paper, an unconventional method of degrading pesticides, non-thermal atmospheric plasma(NTAP), was proposed to degrade the avermectin(AVM) in aqueous solution. Optical emission spectroscopy shows that NTAP, consisting of filamentary streamers, contains a variety of reactive oxygen species(ROS) that may interact with AVM. The high-performance liquid chromatography(HPLC)-MS/MS results indicate that the efficiency of AVM degradation seriously depends on multiple operation parameters of the NTAP,including the applied voltage, treatment time and gas flow rate. The maximum degradation rate of AVM was observed to be 97.47% after 240 s exposure under NTAP with an applied voltage of 18 kV and gas flow rate of 1 l min-1. Molecular dynamics simulation based on a reactive force field for the interaction between O(ground state atomic oxygen) and AVM was performed to analyze the underpinning mechanisms. The simulation result shows the possible pathways of the NTAPgenerated O degrading AVM by destroying the glycosyl group or fracturing the ester group.
基金supported by National Natural Science Foundation of China(Nos.11035005,11475174,50876101)USTC-NSRL Association Funding(No.KY2090130001)
文摘Non-thermal C/H/Ar plasmas are widely applied to carbonaceous material production and processing.In this work,plasma parameters and gaseous species of the atmospheric non-thermal C/H/Ar plasmas produced by an atmospheric-pressure DC arc discharge generator in CH_4/Ar were investigated.The voltage-current characteristics were measured for different CH_4/Ar ratios.Optical emission spectroscopy was employed to analyze the electron excitation temperature,gas temperature and electron density under various discharge conditions.The hydrocarbon molecules produced in the CH4/Ar plasmas were detected with photoionization mass spectrometry.The optical spectral results demonstrated that the electron excitation temperature was 0.4-1 eV,the gas temperature was 2800-4200 K and the electron density was in the range of(5-20)×10^15 cm^-3.The mass spectrum indicated that a variety of unsaturated hydrocarbons(C2H4,C3H6,C6H6,etc.) and several highly unsaturated hydrocarbons(C4H2,C5H6,etc.) were produced in the non-thermal arc plasmas.
基金supported by National Natural Science Foundation of China(No.51176001)
文摘In this paper,the characteristics of detonation combustion ignited by AC-driven non-thermal plasma and spark plug in air/acetylene mixture have been compared in a doubletube experiment system.The two tubes had the same structure,and their closed ends were installed with a plasma generator and a spark plug,respectively.The propagation characteristics of the flame were measured by pressure sensors and ion probes.The experiment results show that,compared with a spark plug,the non-thermal plasma obviously broadened the range of equivalence ratio when the detonation wave could develop successfully,it also heightened the pressure value of detonation wave.Meanwhile,the detonation wave development time and the entire flame propagation time were reduced by half.All of these advantages benefited from the larger ignition volume when a non-thermal plasma was applied.
文摘Ion-acoustic solitary (IAS) waves in electron-positron-ion (e-p-i) plasma have been of interest to many researchers probably due to their relevance in understanding the Universe. However, the study of non-linear ion-acoustic waves in e-p-i plasma with non-thermal electrons has not been adequately studied. A theoretical investigation on non-linear IAS waves in e-p-i plasma comprising of warm inertial adiabatic fluid ions and electrons that are kappa distributed, and Boltzman distributed positron is presented here using the Sagdeev potential technique. It was found that existence domains of finite amplitude IAS waves were confined within the limits of minimum and maximum Mach numbers with varying k values. For lower values of k, the amplitude of the solitary electrostatic potential structures increased as the width decreased, while for high values, the potential amplitude decreased as the width of the solitary structure increased.
文摘In this paper, NiAl layered double hydroxides (NiAl-LDHs) has been modified by non-thermal plasma (NTP) to enhance the fluoride removal capacity of materials. The samples were characterized by X-ray diffraction, Fourier transform infrared spectrometer (FTIR), Thermogravimetric differential thermal analyzer (TG-DTA) and N2 adsorption-desorption. Effects of pH, co-existing anions, temperature and kinetics on F﹣ adsorption were investigated. The results showed that pH affects the adsorbent surface charge. The effective pH range for F﹣ removal was between 4.5 and 10. Lower pH potentially causes dissolution of NiAl-LDHs. The negligible interference of coexisting ions such as makes the NiAl-LDHs a promising sorbent for fluoride polluted water treatment.
基金the Brazilian agencies FAPESP(Nos.2018/10172-7 and 2019/18828-1)CAPES(Finance Code 001),CNPq(No.303580/2021-6)+2 种基金the National Institute of Photonics—INFO(INCTs program)the Universidade de Sao Paulo(USP)Ministère de L’Enseignement Supérieur de la Recherche et de l’Innovation(France)for financial support。
文摘Homogeneous gold nanoparticles were synthesized under atmospheric pressure using a nonthermal helium plasma jet in a single-step process.A current power supply was used to generate the plasma discharge rich in diverse reactive species.These species induce rapid chemical reactions responsible for the reduction of the gold salts upon contact with the liquid solution.In this study,spherical and monodispersed gold nanoparticles were obtained within 5 min of plasma exposure using a solution containing gold(Ⅲ)chloride hydrate(HAuCl_(4))as a precursor and polyvinylpyrrolidone(PVP)as a capping agent to inhibit agglomerations.The formation of these metal nanoparticles was initially perceptible through a visible change in the sample's color,transitioning from light yellow to a red/pink color.This was subsequently corroborated by UVvis spectroscopy,which revealed an optical absorption in the 520-550 nm range for Au NPs,corresponding to the surface plasmon resonance(SPR)band.An investigation into the impact of various parameters,including plasma discharge duration,precursor and capping agent concentrations,was carried out to optimize conditions for the formation of well-separated,spherical gold nanoparticles.Dynamic light scattering(DLS)was used to measure the size of these nanoparticles,transmission electron microscopy(TEM)was used to observe their morphology and X-ray diffraction(XRD)was also employed to determine their crystallographic structure.The results confirm that homogeneous spherical gold nanoparticles with an average diameter of 13 nm can be easily synthesized through a rapid,straightforward,and environmentally friendly approach utilizing a helium atmospheric pressure plasma.
基金the Major Science and Technology Projects of Shanxi Province(No.20181102017)the Hebei Province Central Guidance Local Science and Technology Development Special(No.19943816G)+1 种基金the Open Foundation of Shaanxi Key Laboratory of Lacustrine Shale Gas Accumulation and Exploitation(under planning)the Fundamental Research Funds for the Central Universities(No.2009QH03).
文摘Non-thermal plasma(NTP)is regarded as a potential application for environmental pollution control due to its ability to remove pollutants.As a major precursor of dioxins,the influence of the parameters of 1,2,4-trichlorobenzene(TCB)decomposition using NTP technology was investigated through a series of experiments,including voltage,frequency,water content,initial concentration,flow rate,and oxygen content.The experimental results show that the energy injected into the NTP system has a positive correlation to voltage and frequency.Oxygen has the greatest influence on TCB decomposition.The optimal reaction condition was at 15 kV,1000 Hz,an initial concentration of 20 mg m^?3,a flow rate of 2 l min^?1,H2O at 4%,and O2 at 0%.Under this condition,the TCB removal efficiency could reach 92%.According to the generated product backstepping,the hydroxyl radical(·OH)plays an important role in TCB decomposition due to its strong oxidation,which participates in the dechlorination and oxidation reactions as free radicals,and the possible decomposition pathway of TCB by NTP is inferred from the identified byproducts.It is of great significance to investigate the influence of the parameters of TCB decomposition using NTP technology in order to provide references for industrial application.