Dielectric Barrier Discharge Plasma Research Articles

Sublethal injury and recovery of Escherichia coli O157:H7 after dielectric barrier discharge plasma treatment.

Dielectric barrier discharge (DBD) plasma can be used to control food spoilage and food pathogens. However, DBD plasma may induce sublethal injury in microorganisms, constituting a considerable risk to food safety. This research was designed to investigate the sublethal injury and recovery of Escherichia coli O157:H7 after DBD plasma treatment. The results indicated that the sublethal injury ratios of cells rose along with the augmentation of treatment time and input power of DBD plasma under mild treatment conditions, whereas injury accumulation ultimately culminated in cell death. The highest sublethal ratio of 99.3% was obtained after DBD plasma treatment at 18W for 40s. When solutions such as phosphate buffered saline (PBS), peptone water, glucose solution, and tryptic soy broth (TSB) were used for cell recovery, TSB was proven to be the most efficacious, facilitating the completion of recovery within 2h. The repair ratio of injured cells increased as the recovery pH (3.0-7.0) and temperature (4-37 ºC) increased. Moreover, Mg2+ and Zn2+ were demonstrated to be necessary for the recovery process, while Ca2+ presented a weak effect. Understanding the sublethal injury of bacteria resulting from DBD plasma treatment and their repair conditions can provide useful insight into avoiding the occurrence of sublethal injury as well as inhibiting the occurrence of recovery during food processing and storage.

Polymerization of Sodium 4-Styrenesulfonate Inside Filter Paper via Dielectric Barrier Discharge Plasma

This work explores the polymerization of sodium 4-styrenesulfonate (NaSS) inside filter paper using dielectric barrier discharge (DBD) plasma and its application in the environmental field. The plasma-based technique, performed under mild conditions, solves common problems associated with conventional polymerization inside porous materials. The polymerization process was monitored using Fourier-transform infrared (FTIR) spectroscopy, which confirmed the consumption of double bonds, particularly in NaSS samples containing the optimal concentration of crosslinker divinyl benzene (DVB) (0.25% wt). Our work demonstrates the effectiveness and promise of DBD plasma as a substitute polymerization approach, especially for those in porous materials.

DBD plasma induced SMOSI and encapsulation for regulation of Brønsted-Lewis acid sites of Cr-MOFs@ZrO2

Dielectric barrier discharge (DBD) plasma for the synthesis of Zr-MOFs followed by the calcination and combination with Cr-MOFs was presented to prepare a Brønsted-Lewis bifunctional catalyst for the conversion of glucose to 5-hydroxymethylfurfural (HMF). The strong electric field on the catalyst surface formed by DBD plasma induced the enhancement of strong metal oxide support interaction (SMOSI), which could be indicated by XPS. SMOSI could change the embedding degree of metal micro-particles. SMOSI accompanied with the encapsulation of Zr metal nanoparticles could regulate the acid sites of the catalysts. Lewis acid played an important role in the isomerization of glucose to fructose, while Brønsted acid played a key role in the further conversion of glucose. The strong Brønsted acid sites determined the conversion of glucose to HMF. Cr-MOFs@ZrO2-D with the DBD plasma method afforded a higher Brønsted to Lewis acid ratio, compared with Cr-MOFs@ZrO2-S with the hydrothermal method. Glucose conversion of 97.9 % and HMF yield of 38 % were obtained with DMF solvent system and Cr-MOFs@ZrO2-D at 150 °C for 2h. This research provided a new method for preparing Zr-MOFs by DBD plasma and a new idea to comprehensively understand the role of Brønsted and Lewis acid sites in glucose conversion.

Investigation of highly efficient CO2 hydrogenation at ambient conditions using dielectric barrier discharge plasma

The increasing utilization of CO2 for synthesizing high-value fuels or essential chemicals is a potentially effective approach to mitigating global warming and climate change. Compared to thermal catalytic CO2 conversion under hash operating conditions (400∼500°C, 10 MPa), non-thermal plasma can overcome kinetic barriers and trigger reactions beyond thermal equilibrium at ambient temperature and pressure. In this study, the effects of operating conditions (discharge frequency, input power, and gas flow rate) and geometrical parameters (discharge length, discharge gap, and dielectric materials) have been extensively analyzed using typical cylindrical dielectric barrier discharge (DBD) plasma. The discharge characteristics changed by operating conditions (including waveforms of applied voltage and current) are compared, indicating higher applied voltage and lower gas flow rate can strengthen the filamentary discharges. The results demonstrate CO2 conversion rate increases with the increase of applied voltage and the decrease of CO2/H2 ratio, achieving its maximum value of 43.0% at 20 mL/min. The highest energy efficiency of 3771.9 μg/kJ for CO generation is obtained at the applied voltage of 5.5 kV and gas flow rate of 40 mL/min, respectively. Besides, the constructure of plasma reactor also impacts the performance of CO2 conversion. On the one hand, the discharge gap has a significant role in the variation of CO2 conversion and product selectivity, which is attributed to the electric field density and corresponding electron-induced reaction. On the other hand, the circulating water-cooling jacket was used to find out the influence of reaction temperature, which switched the product from CO to CH4. This work will pave the way for a sustainable alternative towards future CO2 conversion and utilization.

Surface modification of fabrics using dielectric barrier discharge plasma for improved antifouling performance

Abstract Surface modification of fabrics is an effective way to endow them with antifouling properties while still maintain their key advantages like 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 on 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 of processing parameters on fabrics was systematically investigated, like the PFDS concentration, plasma treatment time, and plasma discharge power. An optimum processing condition was determined to be PFDS concentration: 8 wt%, plasma processing time: 40 s, and plasma power: 11.87 W. However, with the 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 the change of their chemical composition and surface roughness. As a result, the surface energy of the fabrics was reduced, accompanied by the improved water and oil repellency properties as well as enhanced antifouling performance. Besides, the plasma-grafted PFDS films also had good durability and stability. By extending the fabrics 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 a guidance for the surface modification of fabrics using DBD plasma to confer them with desirable functionalities.

Ag enhanced CuS nanoflower catalyst coupling dielectric barrier discharge plasma for disinfection performance and mechanism

In this study, the hydrothermal method was employed to grow submicron CuS on carbon cloth (CC), and the photoreduction method was used to grow Ag nanoparticles on the CuS submicron flowers, thus forming the Ag/CuS/CC catalytic electrode. The application of Ag/CuS/CC electrode-coupled dielectric barrier discharge (DBD) plasma in the disinfection of pathogenic bacteria in water was studied. The Ag/CuS/CC electrode exhibits strong antibacterial activity, and under an external voltage of 30 V, the degradation efficiency of Bacillus subtilis reaches 99.99% within 15 min without regeneration. After five cycles, the inactivation rate of Bacillus subtilis reached 99.99% within 25 min. The practical applicability of the Ag/CuS/CC-coupled DBD system for treating actual wastewater was evaluated, and the changes in biological toxicity were investigated. The results indicate that the prepared Ag/CuS/CC coupled DBD has great potential for safe disinfection of pathogenic bacteria in water through integrated processes.

Optimizing beet seed germination via dielectric barrier discharge plasma parameters

This study explores the synergistic effects of gas composition and electric field modulation on beetroot seed germination using dielectric barrier discharge (DBD) plasma. The investigation initially focuses on the impact of air plasma exposure on germination parameters, varying both voltage and treatment duration. Subsequently, the study examines how different gas compositions (argon, nitrogen, oxygen, and carbon dioxide) affect germination outcomes under optimal air plasma conditions. Results indicate that plasma treatment significantly enhances germination rates and seedling growth relative to untreated controls. Notably, plasma exposure alters seed surface morphology and chemistry, increasing roughness, porosity, and hydrophilicity due to the formation of new polar functional groups. The highest germination rate (a 54.84 % increase) and germination index (a 40.11 % increase) were observed at the lowest voltage and shortest duration, whereas higher voltages and prolonged exposure reduced germination, likely due to oxidative stress. Among the tested gas environments, air plasma was most effective in enhancing water uptake and electrical conductivity, while oxygen plasma resulted in the highest germination index and marked improvements in root and shoot length. Conversely, carbon dioxide plasma treatment exhibited inhibitory effects on both germination and subsequent growth metrics. The results highlight the potential of DBD plasma technology to enhance agricultural productivity by optimizing seed germination and early growth. The study emphasizes the importance of precise parameter tuning, particularly gas composition and plasma exposure conditions, to maximize benefits while minimizing adverse effects, offering a refined approach to seed priming in agricultural practices.

Designing persimmon-liked FeOOH-(CrCo)Ox on the plasma-treated cobalt foam for a highly efficient oxygen evolution in an alkaline-seawater electrolyte

Widespread use of high-purity water for hydrogen production in the electrocatalysis field may intensify the shortage of freshwater resource. Although the seawater is abundant, its practical application still faces many challenges due to the adverse chlorine ion reactions and severe corrosiveness, which leads to a low selectivity and poor stability of the anodic oxygen evolution reaction (OER). Herein, the persimmon-like iron-chromium-cobalt metal oxides (FeOOH-(CrCo)Ox) is in-situ engineered on the Co foam surface modified by the dielectric barrier discharge (DBD) plasma (PCF). The obtained FeOOH-(CrCo)Ox/PCF exposes a large specific surface area and rich heterojunction interfaces. Therefore, the optimized electronic structure of FeOOH-(CrCo)Ox/PCF achieves a commercial-grade current density of 1000 mA cm−2 (j1000) with only a overpotential of 348 mV in 1 M KOH, as well as 306 mV for delivering j100 in a harsh alkaline seawater. Additionally, the FeOOH-(CrCo)Ox/PCF also demonstrates an excellent electrocatalytic stability for effectively inhibiting the chlorine corrosion, and only 5.2 % and 17.5 % activity decay occur after 250 h I-t tests with high current densities in 1 M KOH and alkaline seawater, respectively. Furthermore, the DFT results disclose that the synergistic effect between Fe and Co oxides causes a remarkable OER performance, and the Co sites at the FeOOH-CoO interface acts as the main active centers for seawater splitting, promoting the O2 generation effectively.

Experimental Analysis of Flow Separation Control by a Dielectric Barrier Discharge Plasma Actuator in Burst-in-Burst Actuation Mode

This study investigated the effectiveness of a dielectric barrier discharge (DBD) plasma actuator operating in burst-in-burst (BIB) mode for flow separation control on a NACA 0015 airfoil. Time-resolved particle image velocimetry measurements were conducted at a Reynolds number of 66,000 and 13° angle of attack. Various BIB signal configurations were tested, with actuation periods of 70 ms and 150 ms, non-actuation periods ranging from 5 ms to 50 ms, and burst frequencies of 300 Hz and 600 Hz. Proper orthogonal decomposition was applied to analyze the flow field dynamics. The results showed that BIB actuation maintained flow attachment with reduced power consumption compared with continuous burst actuation. However, the effectiveness was highly sensitive to the BIB parameters, with some configurations failing to achieve consistent reattachment and becoming unstable. This study reveals complex interactions between actuation vortices and separation processes, highlighting both the potential and challenges of intermittent plasma actuation for efficient flow control.

Impact of DBD Plasma Jet Treatment on the Enamel Surface of Primary Teeth.

The impact of cold atmospheric plasma (CAP) treatment on the enamel of twelve primary teeth (incisors, canines, and molars) collected from six children was examined in order to evaluate the possibility of using the CAP technique in dental applications. A radio-frequency dielectric barrier discharge (DBD) plasma jet operating at a voltage of 3.25 kV using a mixture of helium and oxygen as the working gas was used for the generation of plasma as part of the electro-technological method for the treatment of biological material. The plasma exposure time for the primary teeth was 5, 10, and 20 min. The properties of tooth enamel (color, contact angles, surface roughness, surface topography, elemental composition) were examined before (control) and after the plasma treatment. As shown by the results, the plasma treatment time is a key parameter that can induce desired features, such as whitening or improved wettability. However, with prolonged plasma treatment (20 min), the enamel surface may be permanently damaged. The cold-plasma-treated samples were characterized by a higher value of the brightness L* parameter and thus a lighter color, compared to the CAP-untreated teeth. It was also evidenced that the plasma treatment increased the hydrophilicity of tooth surfaces, and the contact angles effectively decreased with the time of the CAP treatment. The tooth surface also became much more heterogeneous and rough with much greater amplitudes in heights. The surface of the primary teeth after the CAP treatment lost its homogeneity, as evidenced by the SEM micrographs. The analysis of the elemental composition revealed only minor changes after the plasma process, which may suggest that the observed morphological changes in the enamel surface are mainly physical and are not a consequence of chemical reactions between the enamel and the reactive components of the cold plasma. Plasma treatment of teeth opens up new possibilities of using this method as an alternative to whitening or pre-treatment before other dental procedures.

The Inactivation of E. coli and B. subtilis Spores Treated Individually, Sequentially and Simultaneously with Humified Air Dielectric Barrier Discharge Plasma and Ultraviolet

The Inactivation of E. coli and B. subtilis Spores Treated Individually, Sequentially and Simultaneously with Humified Air Dielectric Barrier Discharge Plasma and Ultraviolet

Improving the Mechanical, Thermoelectric Insulations, and Wettability Properties of Acrylic Polymers: Effect of Silica or Cement Nanoparticles Loading and Plasma Treatment.

The acrylic polymer composites in this study are made up of various weight ratios of cement or silica nanoparticles (1, 3, 5, and 10 wt%) using the casting method. The effects of doping ratio/type on mechanical, dielectric, thermal, and hydrophobic properties were investigated. Acrylic polymer composites containing 5 wt% cement or silica nanoparticles had the lowest abrasion wear rates and the highest shore-D hardness and impact strength. The increase in the inclusion of cement or silica nanoparticles enhanced surface roughness, water contact angle (WCA), and thermal insulation. Acrylic/cement composites demonstrated higher mechanical, electrical, and thermal insulation properties than acrylic/silica composites because of their lower particle size and their low thermal/electrical conductivity. Furthermore, to improve the surface hydrophobic characteristics of acrylic composites, the surface was treated with a dielectric barrier discharge (DBD) plasma jet. The DBD plasma jet treatment significantly enhanced the hydrophobicity of acrylic polymer composites. For example, the WCA of acrylic composites containing 5 wt% silica or cement nanoparticles increased from 35.3° to 55° and 44.7° to 73°, respectively, by plasma treatment performed at an Ar flow rate of 5 L/min and for an exposure interval of 25 s. The DBD plasma jet treatment is an excellent and inexpensive technique for improving the hydrophobic properties of acrylic polymer composites. These findings offer important perspectives on the development of materials coating for technical applications.

Atmospheric Cold Plasma to Maintain Sea Bass Quality: An Opportunity for International Fish Trade

Whole chilled sea bass is an essential product for the European food market, and Türkiye is the foremost supplier. The importance of sea bass in the world food trade reveals the significance of food safety risks that may arise during or after harvest. This study aimed to examine the impact of atmospheric cold plasma (ACP) on delaying the spoilage of sea bass. The ACP is generated by an original device that produces a dielectric barrier discharge plasma using an alternating current (AC) power supply, applying a 30 kV high voltage with a sinusoidal frequency of 20 kHz. Whole sea bass samples were treated for 1 min (ACP1) or 7 min (ACP7), and then stored at 2 ± 1 °C. Sensory scores of plasma-treated sea bass were higher throughout the storage period. Both treatments decreased the initial bacterial load and delayed bacterial growth (p ≤ 0.05) during storage. The mesophilic aerobic bacteria count of control samples exceeded 6 log CFU/g on the second day of storage. However, ACP1 and ACP7 did not reach this value until the third and fourth days. The control samples had higher TMA-N and TBARS (p ≤ 0.05) than plasma-treated groups. The treatment did not significantly change the texture. Although ΔE was higher in ACP samples, a discoloration that could affect acceptability was not reported during the sensory test. Cold plasma can improve the overall market value by maintaining quality, benefiting the global fish trade. It has been shown that cold plasma has promising potential in the fresh fish industry.

Ni‐MOF‐74 Derived Carbon‐Based Ni Catalysts for Efficient Catalytic Ammonia Synthesis via Pulsed DBD Plasma

ABSTRACTDesigning efficient noble metal‐free catalysts for plasma‐catalytic ammonia synthesis is significant and challenging. Carbon‐based metal catalysts were prepared at different pyrolysis temperatures using the Ni‐MOF‐74 precursor. The effects of Ni‐MOF‐74 and its derived carbon‐based metal catalysts on pulsed dielectric barrier discharge (DBD) plasma ammonia synthesis were investigated. The results showed that Ni‐MOF‐74‐300 with both the MOF structure and nickel metal particles exhibited the best catalytic performance for ammonia synthesis. The ammonia synthesis rate reached 41.38 mmol g−1 h−1, whereas the nitrogen conversion rate was as high as 1.54% with an energy yield of 3.04 g kWh−1. Compared to the situation of plasma only, the ammonia synthesis rate, nitrogen conversion rate, and energy yield were increased by 28.46 times, 5.7 times, and 5.5 times, respectively.

Effects of pulse rise time and pulse width on discharge mode transition of SDBD plasma under repetitive pulses

Abstract Affected by environmental states and power supply parameters, the discharge mode of surface dielectric barrier discharge plasma may gradually transfer from O3 mode to NOx mode, resulting in various gas-phase species for different applications. Despite the intensive study of attempts to control this discharge mode transition by changing discharge conditions and power excitations in recent years, the effects of the pulse rise time and the pulse width on the discharge mode transition have not been discussed. In the present study, a surface dielectric barrier discharge was excited by repetitive pulses with different pulse rise times or pulse widths, and the time-varying concentrations of key long-lived species (O3 and NO2) were quantified. The results demonstrated that it was possible to modulate the discharge mode by adjusting pulse rise time/pulse width. The quenching of O3 was observed to occur at a faster rate and the mode transition was noted to occur at an earlier point in time as the pulse rise time decreased from 225 ns to 125 ns and the pulse width increased from 0.5 μs to 4 μs. The employment of a zero-dimensional model for the analysis of plasma chemical kinetics revealed that the reduction in pulse rise time and the prolongation of pulse width resulted in an increase in the mean vibrational energy of N2(v) and a more rapid electrode temperature rise caused by plasma heating. The former enhanced the generation of NO, while the latter accelerated the thermal decomposition of O3, thereby promoting the speed of mode transition.

Chiral Metal-Organic Framework Films with Ordered Macropores for Enantioselective Analysis of Proteins.

Chiral film-based sensors show great promise for discriminating between enantiomers due to their miniaturization and low power consumption. However, their practical use is hindered by the trade-off between enantioselectivity and mass transfer capability, especially concerning biomacromolecules such as proteins. In this work, we present an effective and straightforward method for creating highly organized macropores within crystalline chiral metal-organic framework (CMOF) films. This approach harnesses the shaping influence of a polystyrene nanosphere template and the crystallization induced by the liquid dielectric barrier discharge plasma. The resultant highly ordered macro-microporous structures improve mass diffusion and access to chiral active sites in the hierarchical CMOF films. Coupled with their inherent chirality, strong fluorescence emission, high crystallinity, and exceptional stability, these attributes endow these CMOF films with enhanced sensing capabilities for chiral molecules. Particularly, the macro-microporous structure facilitates efficient protein recognition, overcoming a significant challenge encountered by MOFs due to protein dimensions surpassing MOF pore sizes. These films exhibit increased enantioselectivity, better limits of detection, and wider linear ranges compared with purely microporous CMOF films. This study thus provides a powerful synthetic approach for hierarchical CMOF films, addressing the limitations of traditional thin film sensors and opening an avenue for efficient chiral sensing of large biomacromolecules.

Exploring the CO2 conversion activated by the dielectric barrier discharge plasma assisted with photocatalyst via machine learning

DBD plasma assisted with halide perovskite photocatalysts is very attractive for the conversion of CO2 into high value-added products under mild conditions. However, it is still challenging to further effectively improve the corresponding CO2 conversion efficiency due to the consumption of time, materials, equipments via traditional experimental approach. In this paper, we simulate the CO2 conversion process under the DBD plasma assisted with different photocatalysts by machine learning. The process conditions and material parameters were selected as the feature variables of the machine learning model, and all the features were screened by combining Pearson's correlation coefficient and MIR ranking. The regression algorithms were evaluated using K-fold cross-validation combined with the coefficient of determination (R2), while SVR and BPANN with the best prediction performance for CO2 conversion ratio and energy efficiency were selected to establish the prediction models. In order to increase the accuracy of predictions, the hyperparameters of these two base models were improved using genetic algorithm, particle swarm optimization and Bayesian optimization. The R2 of the GA-SVR-CO2 and Bayesian-BPANN-EE reached 0.8960 and 0.9679 for the testing sets, respectively, and their practical applications were successfully verified. In addition, the effects of feature parameters on the conversion efficiency were revealed by SHAP. SEI scatter plots and Spearman correlation coefficient have been used for correlation analysis to better explore the correlation between machine learning models and experiments. This work brings new insights into the contributions of multiple parameters in the plasma system assisted with photocatalyst for efficient conversion of CO2.

Enhancing insulating properties of glass-fiber reinforced polymers using plasma fluorination-modified boron nitride nanosheets

The insulation failure of glass fiber-reinforced polymers (GFRP) limits their use in high-voltage insulation fields. In this study, boron nitride nanosheets (BNNS) were prepared using ball-milling and further fluorinated via dielectric barrier discharge (DBD) plasma treatment. The GFRP nanocomposites were fabricated using different filler types and doping concentrations. The test results indicated that fluorinated BNNS (F-BNNS) displays good dispersion and interfacial compatibility, enhances the interfacial bonding strength of the “fiber-matrix-filler” ternary system in GFRP, and reduces the internal defects of materials. In addition, the insulating properties of the composites were related to the filler concentration. Adding a trace amount of F-BNNSs increased the flashover and breakdown voltages of the GFRP by up to 28.77% and 21.62%, respectively. The results of molecular dynamics simulations and trap distribution calculations showed that plasma fluorination of BNNS increases the bandgap and deep trap energy level at the interface. The extremely strong charge-binding ability of the deep traps inhibits continuous charge injection and regulates carrier migration, which improves the insulating properties of the composites. The results of this study provide a novel, environmentally friendly, and efficient solution for improving the insulating properties of GFRP.

DBD plasma assisted synthesis of Ce-MIL-88B(Fe) with electron-rich CUSs and mixed-valent bimetallic sites for enhanced photo-Fenton performance

Iron-based metal-organic frameworks (Fe-MOFs) are regarded as a kind of prospective catalysts for photo-Fenton process. However, high cost, rate-limiting Fe(III)/Fe(II) circulation and limited metal sites greatly restricted the application of Fe-MOFs in photo-Fenton system. Ce-MIL-88B(Fe) was synthesized with mixed-valent bimetallic sites and tunable coordinated unsaturated metal sites (CUSs) using dielectric barrier discharge (DBD) plasma with waste PET. The incorporation of Ce altered the structure and the electron aggregation, as well as induced structural defects. Ce substitution in Fe-MOFs induced the regulation of the ratio of Fe ions and formation of electron-rich CUSs, which were beneficial for the rapid adsorption and activation of H2O2, thus enhancing the photo-Fenton performance. The effect of reaction conditions on TC degradation was investigated by response surface methodology (RSM) combined with Box-Behnken design (BBD). This study demonstrates a new perspective on the construction of bimetallic MOFs for the photo-Fenton system.

Enhanced DC surface discharge characteristics of epoxy composites treated by dielectric barrier discharge plasma fluorination and its mechanisms

Surface flashover is a destructive high-voltage discharge phenomenon greatly limiting the update of modern power electronic and electrical equipment. Surface plasma treatment is a high-energy, eco-friendly, and convenience method, it changes the surface properties and owns potential to improve flashover voltage. In the present work, plasma fluorination (PF) technique are used to treat EP/Al2O3 composites, surface morphology, element and bonds content, surface trap, conductivity, charging, and DC flashover voltage are tested and simulated, the effects of plasma on surface discharge are explained through the investigation from microscopic molecular reactions to macroscopic flashover characteristics. It indicates the 20 min PF modified sample exhibits the superior DC flashover performance, increasing by 17 % compare to untreated sample. During PF modification, the epoxy chains are degraded and fluorinated, the degradation rather than fluorination of molecular chains introduce large amounts of shallow traps into the composites, accelerating carriers’ migration and improving surface conductivity, causing surface charges to dissipate through surface conductance. Consequently, the surface electric field distortion degree reduces, and the subsequent gas ionization and plasma formation in the gas phase is suppressed, leading to the improvement of DC flashover voltage after PF modifications.