Plasma Exposure Time Research Articles

Optical Emission Spectra Characterization of Plasma Discharge During the Processing of Milk and Evaluation of its Quality Attributes

This study characterized the optical spectra of continuous low-pressure plasma system and evaluated its effect on milk processing. Plasma was characterized at different input power levels (24.8, 58.9, and 117.6 W which corresponds to the input voltage of 1, 1.5, and 2 kV) with a 1-cm electrode distance. Based on the characterization, the input power level 117.6 W was selected to produce maximum reactive species. The system was operated at 117.6 W to decontaminate milk flowing inside the quartz tube using three different milk flow rates 3, 6, and 9 mL/min (accounting for 5-, 2.5-, and 1-min plasma exposure time). The maximum reduction in total microbial count obtained after treatment was 1.2 log CFU/mL at an exposure time of 5 min (3-mL/min milk flow rate). Significant changes were observed in the physicochemical properties of milk after treatment. However, the only adverse effects observed were the viscosity and color of milk at 5- and 2.5-min treatment, which might be because of the use of unhomogenized milk. The continuous plasma system operated at 117.6 W reduced the microbial load in milk; further optimization of the process parameters is necessary for the complete elimination of microbial load and to increase the shelf life.

Response surface methodology and artificial neural network modeling of work of adhesion on plasma-treated polyester–cotton-woven fabrics

This paper aimed to study the effects of plasma treatment parameters on polyester–cotton of woven fabric surfaces through the work of adhesion test using artificial neural network (ANN) and response surface methodology (RSM). This study used plasma treatment parameters, such as electrode distance, voltage, and plasma exposure time, as inputs for the models. We used surface tension as a function of contact angle (θ) to measure the work of adhesion ( the model's output. Results showed that adhesion is closely related to the selected input variables. In addition, the development of artificial neural networks and response surface methodology could predict the experimental data with the coefficient of determination results were 0.902 and 0.719, and the root-mean-square error (RMSE) values were 2.135138 and 3.685359, respectively. Based on this research, compared with SRM, ANN has higher accuracy in calculating the work of adhesion. We concluded that ANN is expected to be a valuable quantitative method to predict and understand the adhesion effect of plasma treatment on the surface modification of polyester–cotton woven fabrics. The novelty of this study is that we used both ANN and RSM for the first time to predict the work of adhesion of polyester–cotton woven fabric treated with corona plasma. The use of the artificial neural network to simulate and predict the effect of plasma treatment on improving the work of adhesion is another novelty of this research.

Ion bombardment effect on properties of MoOx thin film under different PEALD plasma exposure time

Molybdenum oxide (MoO x ) films have been prepared by using Mo(CO) 6 precursor and remote oxygen plasma reactant via plasma enhanced atomic layer deposition (PEALD) system. The influence of plasma exposure time on the optical, structural, morphological and chemical composition characteristics of the MoO x thin films have been elaborated systematically. The results show that both the plasma oxidizing reaction and ion bombardment effect exist during the films' deposition. Three kinds of different precursor deposition mechanisms of PEALD-MoO x thin films have been proposed firstly and analyzed in detail under different plasma duration, namely unsaturated reaction, saturated reaction and ion bombardment effect. The film growth rate increased with the increment of plasma exposure time and reached a maximum value at 28 s, which manifested the film growth dominated by the plasma oxidizing reaction in this stage and the transformation from unsaturated reaction to saturated reaction. As the further increase of plasma exposure time from 33 to 38 s, the ion bombardment effect couldn't be ignored and led to the formation of more oxygen vacancy defects along with the decrease of refractive index and growth rate. The clarification of the balance mechanism between oxygen radicals' supply and ion bombardment damage is very important for the achievement of high quality MoO x films. • The effect of plasma exposure time on properties of MoO x film has been explored. • Both oxidizing reaction and ion bombardment effect exist during films'deposition. • Three kinds of precursor deposition mechanism have been proposed firstly.

Tuning the structure, optical, and magnetic properties of nanostructured NiMoO4 by nitrogen plasma treatment

Herein, the nitrogen plasma treatment with different time irradiation (0, 90, 120, and 150 min) is used to tune the structure, optical, and magnetic properties of nanostructured NiMoO4 NMO NPs. The XRD patterns revealed that the crystallinity of NMO samples increases with an increase in the N2 plasma exposure time. The notable reduce in this peak’ intensity for the sample at dose of 120 min may be attributed to the energy dissipated in the defect generation. Also, the crystallite size for NMO samples was found in the range (23.9–26.7) nm. Further, EPR is used to evaluate the impact of the treatment duration on the oxygen vacancy density. The total number of spins rises as plasma irradiation duration increases, revealing that the NMO NPs can be used as a dosimeter for plasma irradiation. The optical bandgap ranged from 2.92 eV to 3.24 eV as the N2 plasma treatment duration changed. The saturation magnetization was enhanced with the rise of plasma treatment time. Furthermore, the Hc increases from 16.67 G for untreated NMO NPs to 128.41 G for N2 plasma-treated NMO NPs for 150 min. The resulted optical and magnetic properties of N2 plasma-treated NMO NPs make it candidate material for photocatalysis applications.

Activation of inert polyethylene/polypropylene nonwoven fiber (NWF) by plasma-initiated grafting and amine functionalization of the grafts for Cu(II), Co(II), Cr(III), Cd(II) and Pb(II) removal

In this study, the emulsion graft polymerization of glycidyl methacrylate (GMA) by environmentally friendly plasma-induced technique onto nonwoven polyethylene-coated polypropylene (NWF) fiber and its functionalization with 4-aminobenzoic acid (PABA) were carried out as a novel adsorbent. The influence of plasma source, irradiation time and reaction parameters were studied by a systematic approach. For the grafting of GMA, the optimal plasma treatment conditions using Ar-plasma were found to be 0.2 mbar plasma pressure, 70-watt plasma power, and 120s plasma exposure time. Grafting reaction conditions onto plasma-treated NWF was 4% GMA concentration, 40 °C graft polymerization temperature, and 4 h grafting time. The PABA modification parameters of GMA-grafted NWF fiber have also been optimized for the first time by several solvents and kinetic studies. Epoxy ring in GMA-g-NWF structures (118 ±12% grafting degree) was opened and its modification with PABA was achieved and 81 ± 3% (2.15 mmol PABA/g polymer) conversion was obtained. The samples were characterized by FTIR, XPS, EDX, SEM, contact angle, and TGA techniques. The Cu(II), Co(II), Cr(III), Cd(II) and Pb(II) removal experiments were carried out by ICP-MS in batch mode as a function of pH, contact time, initial concentration and regeneration. Between pH 2–8 range, NWF fabric adsorbent is effective at pH 5 for heavy metal removal. The maximum adsorption capacities (qmax) were determined from Langmuir isotherm as 35.08 mg Cu(II)/ g adsorbent, 31.15 mg Co(II)/g adsorbent, 34.24 mg Cr(III)/g adsorbent, 51.81 mg Cd(II)/g adsorbent and 63.36 mg Pb(II)/g adsorbent, respectively at an initial feed concentration of 100 ppm, demonstrating the promising potential of the NWF fiber-based adsorbent to steadily and efficiently adsorb these toxic metal ions. The experimental data of heavy metals followed pseudo-second-order kinetic and the Langmuir adsorption models. The adsorbent material could be easily regenerated at least five cycles with a 3% HNO3 solution.

Effect of low-pressure radio-frequency air plasma on chitosan films

The effect of low-frequency (15 kHz), low-pressure (10 Pa) air plasma treatment on freshly prepared chitosan films at processing times from 3 to 10 min has been explored. The films were prepared using chitosan solutions in dilute acetic acid. The influence of the plasma exposure time on the composition, morphology, and hydrophilic properties of the film surfaces is discussed.

The Effect of Non-Thermal Atmospheric Pressure Plasma Treatment of Wheat Seeds on Germination Parameters and α-Amylase Enzyme Activity

This contribution presents the results of a study of the germination rate and growth parameters of wheat seeds after atmospheric pressure surface coplanar dielectric barrier discharge (DBD) plasma treatment. The germination rate and biometric parameters such as the root, shoot length, mass of the seedlings, and the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\alpha $ </tex-math></inline-formula> -amylase enzyme activity were studied at different plasma exposure time. The seed coat surface wettability and morphology were determined by apparent contact angle measurement and scanning electron microscope (SEM) analysis. Seed surface disinfection and the presence of filamentous fungi have also been investigated at different discharge parameters. It is shown that the optimal plasma treatment duration for increasing the growth parameters and enhancing the enzymatic activity is 5–15 s. It was found that the longer plasma exposure requires complete sterilization of the seed surface from pathogens, compared to the optimal treatment time for high germination. Based on the obtained results, the possible mechanisms of the positive effect of plasma treatment on the enhanced germination of wheat seeds are discussed.

The effect of non-thermal plasma Jet on bacterial biofilms and plasmid DNA

The effect of non-thermal discharge plasma (DBD) on the inhibition of both gram-positive and gram-negative biofilms bacteria was examined at different plasma exposure times and gas flow. This effect induces damage to aqueous plasmid DNA. It reveals inactivation in bacterial biofilms for both types of bacteria with an increase in time of direct exposure to plasma and an increase in gas flow. The presence of positive bacteria outweighs the negative bacteria in susceptibility to inhibition. The resulting fractions of the DNA indicate whole DNA double-strand breaks and were determined using agarose gel electrophoresis. The damage level induced in the plasmid DNA is also enhanced with increased plasma irradiation time.

A new plasma-based approach to hydrogen intercalation of graphene

In this work a new plasma-based approach to hydrogen intercalation of Graphene grown on SiC is demonstrated. By optimization of the inductively coupled plasma parameters the intercalated by hydrogen Graphene has been modified gradually and transformed into the two-dimensional hydrocarbon Graphane. The intermediate stages during the transition of Graphene to Graphane were studied by means of Raman spectroscopy and AFM. The dependence of the intensities of the Raman Graphene fingerprints: D and G peaks on the hydrogen intercalation time has been studied. The changes of resistance during the hydrogen plasma treatment were parsed. The Raman (D + D′) peak corresponding to hydrogenated graphene was studied in detail. The method developed is highly reliable and flexible as well as convenient for large-scale fabrication of Graphane to be employed as a hydrogen storage material and in 2D electronics. • A new plasma-based approach to H 2 -intercalation of Graphene is demonstrated. • The bonding modification during the transition of Graphene to Graphane has been monitored by different analytical techniques. • The resistance of the material studied depends linearly on the plasma treatment time. • Raman peaks evolution with the hydrogen plasma exposure time was investigated.

Statistical Study of Nonthermal Plasma-Assisted ZnO Coating of Cotton Fabric through Ultrasonic-Assisted Green Synthesis for Improved Self-Cleaning and Antimicrobial Properties.

Nonthermal plasma processing is a dry, environment-friendly and chemical-free method of improving the wettability, adhesion, self-cleaning and dying quality of fabrics without affecting their bulk properties. This study presents a green synthesis and coating method for the immobilization of nanoparticles of ZnO on the nonthermal plasma functionalized cotton fabric. The self-cleaning activity of ZnO-coated cotton was then optimized statistically. The ultraviolet protection and antimicrobial activity of the optimized and a control sample were also elaborated in this study. Psidium guajava Linn (guava) plant extract and zinc chloride were used in the ultrasonic biosynthesis of ZnO nanoparticles and concurrent immobilization over plasma functionalized cotton. Sodium hydroxide was used as a reaction accelerator. Statistical complete composite design (CCD) based on the amount of ZnCl2, NaOH and plasma exposure time was used to optimize the role of input parameters on the self-cleaning ability of the coated cotton. Methylene blue in water was used as a sample pollutant in the self-cleaning study. The ZnO-coated cotton showed notably high self-cleaning activity of 94% and a UV protection factor of 69.87. The antimicrobial activity against E. Coli and S. Aureus bacteria was also appreciably high compared to the control.

(Invited) Role of Low-Energy Ions during Plasma-Enhanced Atomic Layer Deposition

This contribution will discuss the role and impact of ions during plasma-enhanced atomic layer deposition (ALD), in the context of the latest trends in nanoelectronic device fabrication. Due to the ongoing downscaling of semiconductor device structures, atomic-scale processing techniques such as plasma ALD are becoming increasingly important and more widely applied. Detailed insight into the role of ions is essential, now more than ever, for further advancing the atomic-level precision that plasma ALD offers.Among others, it will be presented that even ions with a low energy of <20 eV, as typical when using a grounded substrate and a remote plasma source, can considerably influence plasma ALD processes. This will be illustrated using plasma ALD of SiO2 and TiO2 as industry-relevant case studies. Specifically, it is observed that (low-energy) ions contribute to the film quality of SiO2,1 can induce crystallization during plasma ALD of TiO2,2 and can alter the growth per cycle by a factor of up to ~2 (for both SiO2 and TiO2). These effects can have important consequences for applications, for instance on the film conformality obtained on 3D nanostructures.Furthermore, the mechanisms governing the influence of ions on an elementary level will be discussed. An important topic here is the combined effect of ion energy, ion flux and plasma exposure time. These parameters can all have a different impact, depending on the plasma and material system. For plasma ALD of SiO2 and TiO2 the combined effect can be universally described by the ion energy dose (i.e., ion energy × flux × exposure time),3 where a minimal effect is obtained when supplying a dose of <1 eV nm-2 cycle-1, or a strong effect when supplying a dose of >100 eV nm-2 cycle-1.1,2 In conclusion, general insights into the role of ions during plasma ALD will be presented, which are particularly important for advancing the level of control over film thickness and material properties in the fabrication of (next-generation) nanoelectronics. Arts et al., Appl. Phys. Lett. 117, 031602 (2020).Arts et al., Impact of ions on film conformality and crystallinity during plasma-assisted atomic layer deposition of TiO2 (to be published).Faraz et al., Plasma Sources Sci. Technol. 28, 024002 (2019). Figure 1

Study on CO2-based plasmas for surface modification of polytetrafluoroethylene and the wettability effects

Surface modification of polymers is an attractive way to endow them with new interfacial properties while maintaining desirable bulk properties, thus expanding their possible applications. In the present work, CO2/N2 DBD plasma was applied for the surface modification of polytetrafluoroethylene (PTFE) membranes by using acrylic acid as the precursor. Systematic experiments has been carried out to investigate the influence of the plasma gas composition and the plasma exposure time to the composition, morphology, and wettability performance of the PTFE membranes. It is shown that acrylic acid has been successfully grafted on the surface of PTFE to form carboxylic functional groups by the plasma technique, leading to improved hydrophilicity. The increase of the CO2 content in CO2/N2 mixtures results in enhanced generation of CO, CO, and CC species, suggesting CO2 has been converted to functional groups on the surface of PTFE membranes. Moreover, at plasma exposure time of 0˜60 s, the hydrophilicity of the PTFE membranes can be improved, while longer plasma exposure time would lead to the degradation of the formed coating, leading to reduced hydrophilicity. This is also demonstrated by the quality of printed text on the corresponding PTFE membranes. The CO2-based plasma method was further extend to the surface modification of substrates like polyethylene (PE), polyvinylidene fluoride (PVDF), and plexiglass, suggesting high versatility of the process to alter their wettability performance. This study provides useful insight for the utilization and conversion of CO2 into value-added carboxylic groups on polymers via plasma technique.

The effects of argon plasma treatment on ITO properties and the performance of OLED devices

In this work, the surface of indium tin oxides (ITO) was treated with argon plasma at different plasma exposure times, namely 4, 6, and 8 min. The effect of treatment on the physical properties of ITOs and the performance of organic light-emitting diodes (OLEDs) using a glass/ITO/PEDOT: PSS/Alq3/Al structure were investigated. The ITOs were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and visible-ultraviolet (UV–vis) spectroscopy. Based on the results, the treatment does not change the structure and transparency of ITOs; however, it improves the surface morphology and reduces the value of the surface roughness of ITOs. OLEDs fabricated by the current density profile, resistance, and radiation were investigated. The study results showed a decrease in turn-on voltage (from 5.7 to 3 V) and resistance on the one hand, and an increase in irradiance due to surface treatment by plasma on the other hand.

Effects of Dielectric Barrier Ambient Air Plasma on Two Brassicaceae Seeds: Arabidopsis thaliana and Camelina sativa.

We investigated low-temperature plasma effects on two Brassicaceae seeds (A. thaliana and C. sativa) using dielectric barrier discharge in air. Comparisons of plasma treatments on seeds showed distinct responses on germination rate and speed. Optimal treatment time giving optimal germination is 15 min for A. thaliana with 85% increase compared to control after 48 h of germination and 1 min for C. sativa with 75% increase compared to control after 32 h of germination. Such germination increases are associated with morphological changes shown by SEM of seed surface. For better understanding at the biochemical level, seed surfaces were analyzed using gas chromatography-mass spectrometry which underlined changes of lipidic composition. For both treated seeds, there is a decrease of saturated (palmitic and stearic) fatty acids while treated C. sativa showed a decrease of unsaturated (oleic and linoleic) acids and treated A. thaliana an increase of unsaturated ones. Such lipid changes, specifically a decrease of hydrophobic saturated fatty acids, are coherent with the other analyses (SEM, water uptake and contact angle). Moreover, an increase in A. thaliana of unsaturated acids (very reactive) probably neutralizes plasma RONS effects thus needing longer plasma exposure time (15 min) to reach optimal germination. For C. sativa, 1 min is enough because unsaturated linoleic acid becomes lower in treated C. sativa (1.2 × 107) compared to treated A. thaliana (3.7 × 107).

Experimental and statistical analysis of dielectric barrier discharge plasma effect on sonochemically TiO2 coated cotton fabric using complete composite design

A single step ultrasonic biosynthesis method was used to synthesize and coat TiO2 nanoparticles onto DBD plasma functionalized raw cotton. Titanium isopropoxide was reduced with aloe vera plant extract into TiO2 nanoparticles. The effect of DBD plasma treatment on self-cleaning property of TiO2 coated fabric was optimized statistically by using a complete composite design. To induce functional groups on the cotton fabric surface, the fabric was pre-treated with DBD plasma over various periods of time. The plasma exposure time, molarity of solution and ultrasonication time were optimized using complete composite design package. TiO2 nanoparticles revealed spherical shape and anatase phase with average crystallite size of 10.46 nm. The statistically optimized plasma exposure time, molarity and sonication time was 7 min, 0.80 and 75 min, respectively. The plasma activation of fabric significantly improved the adsorption, tensile strength and self-cleaning ability of TiO2 coated fabric.

Effect of O2 plasma exposure time during atomic layer deposition of amorphous gallium oxide

Amorphous gallium oxide thin films were grown by plasma-enhanced atomic layer deposition on (100) silicon substrates from trimethylgallium Ga(CH3)3 precursor and oxygen plasma. At 200 °C, the growth per cycle is in the range of 0.65–0.70 Å for O2 plasma exposure times ranging from 3 up to 30 s during each cycle. The effect of O2 plasma exposure times on the interfacial SiOx regrowth and the electrical properties was investigated. In situ spectroscopic ellipsometry shows that the SiOx regrowth occurs during the first three cycles and is limited to 0.27 nm for plasma times as long as 30 s. Increasing the O2 plasma exposure during each ALD cycle leads to a drastic decrease in the leakage current density (more than 5 orders of magnitude for 30 nm films), which is linked to the suppression of oxygen vacancy states as evidenced by spectroscopic ellipsometry. Interestingly, an increase in the dielectric constant with increasing O2 plasma exposure time is observed, reaching a value of εr∼14.2, larger than that of single crystalline β-Ga2O3. This study highlights the crucial role of oxygen plasma exposure time in the control and tuning of the electrical properties of amorphous gallium oxide films.

Plasma-enhanced atomic layer deposition of SiO2 film using capacitively coupled Ar/O2 plasmas: A computational investigation

Plasma-enhanced atomic layer deposition (PE-ALD) is widely used for dielectric deposition in semiconductor fabrication due to its ability to operate at low temperatures while having high precision control. The PE-ALD process consists of two subcycles: precursor dosing and plasma exposure with gas purging and filling in between. In the PE-ALD of SiO2, a Si-containing precursor is first deposited on the surface, usually in a plasma-free environment. The surface is then exposed to an oxygen-containing plasma during which the residual components of the precursor are removed and the Si oxidized. Various factors affect the outcome of SiO2 PE-ALD, such as exposure times during each step, steric hindrance of the Si precursor, and plasma properties, such as the energy of ions incident onto the film. The results from computational investigations of the first layers of SiO2 PE-ALD at both reactor (cm) and feature (nm) scales are discussed in this paper. The example system uses bis(tertiary-butylamino)silane, SiH2[NH(C4H9)]2 as the silicon precursor during dosing and plasmas operating in Ar/O2 gas mixtures during the oxidation step. Parametric studies were performed for blanket deposition, as well as deposition in trenches and vias while varying power, pressure, plasma exposure time, aspect ratio, and ligand retention in the film. The general trends show that conditions that reduce the fluence of reactive oxygen species typically decrease the O/Si ratio, increase the vacancies in the films, and decrease the order of the film. Conditions that result in higher ion fluxes having higher energies produce the same result due to sputtering. The retention of ligand groups from the precursor significantly decreased growth rates while increasing vacancies and reducing the O/Si ratio.

Bactericidal efficiency of silver nanoparticles deposited on polyester fabric using atmospheric pressure plasma jet system

Plasma technology offers an appealing approach for the surface modification of materials such as textiles. In this study, an atmospheric pressure plasma jet system was used to successfully deposit silver nanoparticles on polyester textile substrates to impart antibacterial properties. The plasma was generated by applying a constant potential of 15 kV to silver electrodes while argon and oxygen gases were allowed to flow at 15 and 5 LPM, respectively. The optical emission spectra of the generated plasma revealed the presence of argon, oxygen, and silver species. The combination of operating parameters employed in the study led to the successful deposition and adhesion of silver nanoparticles without changing the bulk properties of the material. The deposited silver nanoparticles were verified using a scanning electron microscope analysis which showed an expected increase in particle density at longer plasma exposure time. Qualitative and quantitative antibacterial assays proved the efficiency of the plasma-treated textile samples in inhibiting the growth of the Gram- negative Escherichia coli and the Gram-positive Staphylococcus aureus bacteria. The antibacterial efficiency of the treated samples proportionally increased with longer plasma treatment time. The approach used in this study successfully produced surface-immobilized silver nanoparticles polyester textile with potential application as antibacterial fabrics.

Enhanced biomass and cadmium accumulation by three cadmium-tolerant plant species following cold plasma seed treatment

Cold plasma seed treatment can promote plant growth and enhance the resistance of agricultural crops to adverse stress. However, the effects of plasma seed treatment on the growth and phytoextraction response of plants to cadmium (Cd) remain poorly documented. Here, we have investigated the feasibility of using plasma seed treatment to enhance the biomass and Cd accumulation of three Cd-tolerant species, namely Bidens pilosa L, Solanum nigrum L. and Trifolium repens L, under different plasma treatment conditions. Possible enhancement mechanisms are also proposed according to the levels of organic acids in the roots and the Cd fractions in rhizosphere soil following different plasma treatment conditions. The optimum plasma power was 100 W (B. pilosa) or 500 W (S. nigrum and T. repens). The optimum plasma exposure time for all three species was 60 s. Plasma seed treatment under the optimum treatment conditions enhanced plant dry biomass by ~17.3–45.0% and Cd accumulation by 8.8–54.4% across all three species compared to the controls. Furthermore, the phytoremediation efficiencies, bioaccumulation factors and transfer factors of the three species also increased significantly after seed plasma treatment. The promotion of plasma treatment on the biomass and Cd accumulation of three species might be due to increased exudation of organic acids from the roots into the rhizosphere soil, thus increasing the concentrations of acid-soluble Cd to form Cd-organic acid complexes that facilitated the uptake and translocation of Cd by the plants. Results of this study revealed that cold plasma seed treatment is an environmentally friendly, economical and efficient means to develop the application of phytoremediation for Cd-contaminated soils.

Plasma Treatment Effects on Oral Candida albicans Biofilms.

The objective of this study is to evaluate the plasma treatment effects on oral fungal biofilms. Candida albicans biofilms were developed on the 48-well plate to serve as a model of oral fungal biofilm. The treatment of 0.2% chlorhexidine digluconate (CHX) was used as a positive control compared with plasma treatments. The efficacy of treatments was determined by 3-(4,5-dimethylazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and confocal laser scanning microscope (CLSM). The survival percentage of Candida albicans decreased from 52% to 27% as the plasma power increased from 6mA to 8mA and plasma exposure time extended from 2 min to 10 min. Moreover, it was found that there is a synergistic effect of the combination of plasma and CHX treatments. Scanning electron microscopy (SEM) examination indicated severe cell damages resulting from plasma treatment. In conclusion, the low-temperature plasma treatment is effective in deactivating Candida albicans biofilms and thus provides a promising alternative to disinfect oral fungal biofilms.