Cyclonic Atmospheric Pressure Plasma Research Articles

The investigation of deposited organic carbon‐silicon films using cyclonic atmospheric pressure plasma polymerization

AbstractBackgroundThe upgrading of atmospheric‐pressure plasma polymerization process, the detailed investigation of atmospheric‐pressure plasma polymerization deposited organic carbon‐silicon film features is essential to obtain the further understandings into the optimizing coating techniques.AimThis investigation demonstrates plasma cyclone deposited film features with adjusting argon gas flow rate and HMDSN monomer flow rate.MethodThis study utilized the plasma cyclone system to polymerize a carbon‐silicon film. In this study, Optical Emission Spectroscopy (OES) was employed as a diagnostic tool to indirectly inspect the chemical composition of the atmospheric‐pressure plasma polymerization's glow discharge by detecting the photo‐emitting species. The Contact Angle Goniometer, ATR‐FTIR, AFM, and XPS were used to measure the surface properties of the films deposited by plasma cyclone.ResultsThe static contact angle results show that most of the deposited films obtain the divergent contact angle values with adjusting argon gas flow rate and HMDSN monomer flow rate. ATR‐FTIR results show that argon gas flow rate and HMDSN monomer flow rate dominate the porosity of plasma cyclone deposited film surface. XPS and AFM analyses also detect the comparable trend of physicochemical characteristics of organic carbon‐silicon film with adjusting argon gas flow rate and HMDSN monomer flow rate. In summary, the organic carbon‐silicon films can be successfully polymerized by plasma cyclone.ConclusionsThe results refer that the organic carbon‐silicon film deposition on vanadium redox flow battery separator surface improved the electrolyte uptake of the cyclonic‐plasma‐coated separators was larger than that of a commercial separator.

A study of plasma power effects on surface activation of polystyrene

In this study, polystyrene (PS) surface activation was performed with cyclonic atmospheric-pressure plasma to improve surface hydrophilicity, and the effects of plasma power on cyclonic plasma surface activation were investigated. Altered PS surface characteristics were observed through a wettability analysis. The PS surface hydrophilicity was highly enhanced during the cyclonic plasma treatment. The substantial growth of the PS surface hydrophilicity was attributed to the crosslinking by activated species of inert gases due to the presence of cyclonic plasma. Optical emission spectroscopy was used to determine various chemical plasma species and the association of the plasma surface treatment with the changes in the electron density and electron excitation temperature in cyclonic plasma with increasing plasma power. X-ray photoelectron spectroscopy (XPS) and atomic force microscopy were used to determine the chemical and morphological variations on the cyclonic plasma-treated PS surface. The XPS analysis exhibited noticeably higher surface concentrations of oxygen functional groups on the cyclonic plasma-activated PS surface compared to the untreated PS. The results show that cyclonic plasma is an operative plasma device that can be used to improve PS surface hydrophilicity.

Effects of cyclonic plasma deposited organosilicon nano‐coating on 316 stainless steel and its surface characterization

Cyclonic atmospheric pressure plasma is developed to synthesize the organosilicon nano‐coating on 316 L stainless steel surface with hexamethyldisilazane (HMDSN) and HMDSN/N2 monomers. The modified 316 L stainless steel surface characteristics of cyclonic plasma deposited organosilicon nano‐coating were evaluated by the static contact angle measurement, FTIR, SEM, AFM, and XPS detections. The chemical analysis with FTIR and XPS depicts that cyclonic plasma deposited nano‐coating obtains the relatively inorganic characteristics. The surface morphological determination with SEM and AFM refers cyclonic plasma deposited 316 L stainless steel surface roughness alteration with switching monomer inputs. This study shows the potential of chamber‐less deposition to create the plasma deposited organosilicon nano‐coating for 316 L stainless.

Spectroscopic Diagnostics of Enhanced Magnetron and Mesh Separation Effects in Cyclonic Atmospheric Pressure Plasma Surface Modification of Polyethylene Terephthalate

The correlation of plasma surface modification consequence and the electron characteristics in plasma state with the enhanced magnetron source and metal mesh screen are studied by cyclonic-atmospheric-pressure plasma on polyethylene terephthalate (PET) surface. The contact angle measurement is employed to examine the plasma modified PET surface hydrophilicity. Optical emission spectroscopy is used to detect the electronic excitation temperature and electron density in cyclonic atmospheric pressure plasma. The electronic excitation temperature and the electron density are measured as the operational conditions of adding magnetron source and metal mesh separation. Boltzmann plot method is employed to estimate the electronic excitation temperature whereas electron density measurement by the Voigt profile. The results show that both electronic excitation temperature and electron density have similar trend i.e., both increasing with the enhanced magnetron source while decreasing trend is observed with passing through the metal mesh.

Plasma polymerization of acrylic acid onto polystyrene by cyclonic plasma at atmospheric pressure

The cyclonic atmospheric-pressure plasma is developed for chamberless deposition of poly(acrylic acid) film from argon/acrylic acid mixtures. The photoemission plasma species in atmospheric-pressure plasma polymerization was identified by optical emission spectroscopy (OES). The OES diagnosis data and deposition results indicated that in glow discharge, the CH and C2 species resulted from low-energy electron-impact dissociation that creates deposition species, but the strong CO emission lines are related to nondeposition species. The acrylic acid flow rate is seen as the key factor affecting the film growth. The film surface analysis results indicate that a smooth, continuous, and uniform surface of poly(acrylic acid) films can be formed at a relatively low plasma power input. This study reveals the potential of chamberless film growth at atmospheric pressure for large-area deposition of poly(acrylic acid) films.

Cyclonic plasma activation on microporous poly(vinylidene fluoride) membranes for improving surface hydrophilicity

To improve microfiltration (MF) flux, microporous poly(vinylidenefluoride) (PVDF) membranes were modified by cyclonic atmospheric-pressure plasma (CAPP). The surface hydrophilicity change of a PVDF membrane was monitored based on static contact angle measurements. The PVDF membrane surface became highly hydrophilic when exposed to CAPP for only 30 s. A significant increase in the surface energy of PVDF membranes attributable to the CASING (crosslinking via activated species of inert gases) effect was observed. Optical emission spectroscopy (OES) was used to determine various chemical species of CAPP processing. X-ray photoelectron spectroscopy (XPS) and confocal laser scanning microscopy (CLSM) were employed to characterize the chemical and morphological changes on the treated PVDF membrane surface. The XPS analysis showed considerably higher surface concentrations of oxygen functional groups on the CAPP-functionalized PVDF membrane surface compared to the untreated one. The membrane surface hydrophilicity was increased by plasma treatment, leading to an increase in filtration flux. The present results show that CAPP is an efficient tool that can be used to enhance the surface hydrophilicity of PVDF membranes.

Tailoring Surface Properties of Nonwoven Polypropylene by Cyclonic Atmospheric Pressure Plasma

Polypropylene nonwoven materials have foundenormous usefulness in many applications. In this paper, the cyclonic plasma processing at atmospheric pressure was used to determine the surface treatment effect. The change of hydrophilicity was determined by contact angle analysis. The nonwoven polypropylene (NWPP) surface became greatly hydrophilic when exposed to the cyclonic plasma at atmospheric-pressure. A major effect in the surface free energy of material surface due to crosslinking via activated species of inert gases effect was observed. The variations in the chemical structure and surface morphology of the NWPP were confirmed by X-ray photoelectron spectroscopy (XPS) and scanning electron microscope detections. The XPS detection reveals considerably more surface elemental composition of oxygen atoms for cyclonic plasma-modified NWPP.

Surface modification of PVDF ultrafiltration membranes by remote argon/methane gas mixture plasma for fouling reduction

Ultrafiltration (UF) is considered as a potential alternative to gravity settling in liquid surfactant membrane process for fast separation of water-in-oil (W/O) emulsions from the external aqueous phase. Flux behavior was studied in this work during batch UF of W/O/W solutions by poly(vinylidene fluoride) (PVDF) membrane with a molecular weight cut-off of 30kDa after the membrane was modified by remote cyclonic atmospheric-pressure plasma with argon gas and methane/argon gas mixture. Physicochemical properties of the membrane surfaces including hydrophilicity, functional group concentrations, and pore size distribution before and after plasma modifications were determined by static contact angle measurements, X-ray photoelectron spectroscopy, and capillary flow porometry, respectively. Higher surface concentrations of oxygen functional groups for plasma-functionalized membranes were observed compared to the unmodified membranes. It was shown that UF flux was significantly enhanced with the plasma-modified membranes under the conditions studied (feed, 5vol% W/O emulsions; stirring, 300rpm; pressure, 35–138kPa). Resistance-in-series analysis of the flux data indicated that the proposed remote plasma treatment, particularly with methane/argon gas mixture, could considerably reduce both resistances due to solute adsorption and cake layer formation on the membrane surface, although the above two resistances always contributed more than 71% of the total filtration resistance.

Surface Treatment and Characterization of Indium–Tin-Oxide Thin Films Modified Using Cyclonic Atmospheric-Pressure Plasma

The surface characteristics of indium–tin-oxide (ITO) films modified using cyclonic atmospheric-pressure plasma were investigated by static contact angle (CA) analysis as well as atomic force microscopy (AFM). The surface modification effects of plasma operational conditions including treatment time, plasma power, gas flow rate, and distance of nozzle to the substrate on the ITO surface features were examined. Cyclonic atmospheric pressure plasma-modified ITO films showed a significant decrease in static water contact angle. The surface energy calculated by the Owens–Wendt method primarily increased from the polar component after cyclonic atmospheric pressure plasma treatment. The glow feature and luminous plasma species in the cyclonic atmospheric pressure plasma were identified by optical emission spectroscopy (OES). Atomic force microscopy revealed that the cyclonic atmospheric pressure plasma-modified ITO surface showed a slightly increased surface roughness and a similar morphology to the untreated ITO surface. As a result, it is believed that this cyclonic atmospheric pressure plasma alters the ITO surface physicochemical features, which can in turn improve ITO films performance for various applications.

Large-Area Organosilicon Film Deposition Using Cyclonic Atmospheric Pressure Glow Discharge

Cyclonic atmospheric pressure plasma is developed for chamberless deposition of organosilicon thin films from argon/hexamethyldisoxane (HMDSO) mixtures. The surface properties of the resulting plasma films were investigated as a function of RF plasma power. Film characterization was performed by static contact angle measurement, scanning electron microscopy (SEM), atomic forced microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). It was found the RF plasma power is the key factor that to affects the film growth in the atmospheric pressure plasma chemical vapor deposition process. SEM and AFM results indicated that a smooth, continuous, and uniform surface of organosilicon thin films can be formed at a relatively low plasma power input. XPS indicated that atmospheric-pressure plasma-deposited organosilicon films present mainly inorganic characteristics. This study shows a potential of chamberless film growth at atmospheric pressure to form organosilicon thin films for large-area deposition.

Tailoring Surface Properties of Polymeric Separators for Lithium‐Ion Batteries by Cyclonic Atmospheric‐Pressure Plasma

AbstractThis paper reported surface modification and characterization of polymeric separators by cyclonic atmospheric‐pressure plasma for Li‐ion battery use. Water contact angles of the plasma‐modified polymeric separator decreased with increasing treatment time and plasma power. Variations in surface morphology and chemical structure of the plasma‐modified polymeric separators were confirmed by FESEM and XPS. XPS analysis revealed that the surfaces of plasma‐modified polymeric separators had significantly higher concentrations of oxygen functional groups. Moreover, the cyclonic atmospheric‐pressure plasma‐modified polymeric separators showed excellent performance in electrochemical measurements. magnified image

Degradation of Bacillus Subtilis by Cyclonic Atmospheric-Pressure Plasma

This paper investigates the sterilization effects of a low-temperature cyclonic atmospheric-pressure plasma. Bacillus subtilis was exposed to the cyclonic atmospheric-pressure plasma, and the degradation of the bacterial cell was thoroughly examined with scanning electron microscopy. It was found that cyclonic atmospheric-pressure plasma is effective in the destruction of the B. subtilis cells.

Static Water Contact Angle Analysis of Cyclonic Atmospheric Pressure Plasma-Activated Polycarbonate

Polycarbonate (PC) films were activated using cyclonic atmospheric pressure plasma. The experimentally measured gas phase temperature was from 30 to 95 °C, demonstrating that this cyclonic atmospheric pressure plasma can treat heat-sensitive polymeric materials at the low temperatures. The surface hydrophilicity changes of cyclonic atmospheric pressure plasma-treated PC films were determined by water contact angle analysis. The activation effects of plasma operational parameters including treatment time, plasma power, and distance of nozzle to substrate on the PC surface features were investigated. The glow feature and luminous plasma species in the cyclonic atmospheric pressure plasma were identified by optical emission spectroscopy (OES). Cyclonic atmospheric pressure plasma-activated PC films showed a significant decrease in water contact angle. In this investigation, we developed an innovative technique for chamberless polymeric surface activation by this atmospheric pressure plasma processing.

Contact angle analysis of low-temperature cyclonic atmospheric pressure plasma modified polyethylene terephthalate

Polyethylene terephthalate (PET) films are modified by cyclonic atmospheric pressure plasma. The experimentally measured gas phase temperature was around 30 °C to 90 °C, indicating that this cyclonic atmospheric pressure plasma can treat polymers without unfavorable thermal effects. The surface properties of cyclonic atmospheric pressure plasma-treated PET films were examined by the static contact angle measurements. The influences of plasma conditions such as treatment time, plasma power, nozzle distance, and gas flow rate on the PET surface properties were studied. It was found that such cyclonic atmospheric pressure plasma is very effective in PET surface modification, the reduced water contact angle was observed from 74° to less than 37° with only 10 s plasma treatment. The chemical composition of the PET films was analyzed by X-ray photoelectron spectroscopy (XPS). Atomic force microscopy (AFM) was used to study the changes in PET surface feature of the polymer surfaces due to plasma treatment. The photoemission plasma species in the continuous cyclone atmospheric pressure plasma was identified by optical emission spectroscopy (OES). From OES analysis, the plasma modification efficiency can be attributed to the interaction of oxygen-based plasma species in the plasma with PET surface. In this study, it shows a novel way for large scale polymeric surface modification by continuous cyclone atmospheric pressure plasma processing.

Low-Temperature Cyclonic Plasma Created at Atmospheric Pressure

Cyclonic atmospheric pressure plasma with low-temperature nature has been investigated. High-speed rotating nonthermal atmospheric plasma jets were utilized as RF plasma sources to provide the gas velocities required to generate the cyclonic gas flow patterns. It was shown that the plasma temperature could be controlled by operational parameters. The experimentally measured gas phase temperature was around 30degC-85degC, indicating that this cyclonic atmospheric pressure plasma can treat polymers without unfavorable thermal effects. This type of low-temperature atmospheric plasma can provide a novel technique for large-scale surface modification of heat-sensitive materials.