Effect Of Argon Plasma Treatment Research Articles

Effects of argon plasma treatment on carbon fiber surface characteric and its reinforcing polyimide composites interfacial properties at room and elevated temperatures

In high temperature conditions, this can cause considerable changes in the mechanical properties of the composite. In order to determine the structural and mechanical property changes that occur in composite materials at elevated temperatures, to elucidate the damage mechanisms at elevated temperatures, and to improve the stability and durability of the materials. This paper studies how plasma treatment time affects the surface polarity, roughness, wettability and mechanical properties of carbon fibers. The results showed that the best wettability was attained after 10 min of plasma treatment, and new oxygen-containing functional groups (COO- and -C=O) developed on the fiber surface. The fundamental explanation is that during plasma surface treatment, the CH group in the bisphenol A part chain segment present in the epoxy resin sizing agent's composition is oxidized, forming an organic oxide layer. In this paper, the plasma modification technology was utilized to improve the interfacial compatibility of carbon fiber and Polyimide (PI) resin, and the interlaminar shear strength reached 103.98 MPa, up 10.49 %, and the strength retention rate was 84.3 % at 300 °C. In this paper, the plasma modification technique was employed to increase the interfacial compatibility of carbon fiber and PI resin. It was found that the Inductively Coupled Plasma (ICP) treated carbon fiber surfaces underwent physical and chemical changes that effectively enhanced the interfacial compatibility with the resin. However, the chemical groups and physically etched regions on the surface of the plasma-modified fibers are able to impede the relative motion of the resin to a certain extent, thus improving the interfacial strength.

The effect of argon plasma treatment on surface engineering in an inverted perovskite solar cell

The effect of argon plasma treatment on surface engineering in an inverted perovskite solar cell

Effect of Argon Plasma Surface Treatment on Repair of Resin Composite Aged Two Years.

To evaluate the effect of argon plasma treatment (PLA) when combined with sandblasting (SAN), silanization (SIL), and hydrophobic bonding resin (HBR) on the shear bond strength (SBS) of a two-year water-aged resin composite bonded to a newly placed composite after 24 hours and one year of water-storage. Thirty-six light-cured composite plates (20mm x 20mm x 4mm thick) were obtained and stored at 37°C in distilled water for 2 years. These aged plates were distributed into 6 groups (n=6) according to the surface treatment: no treatment (Negative Control); SAN+SIL+HBR (Positive Control); SAN+PLA+SIL+HBR; PLA+ SIL+HBR; PLA+SIL; PLA+HBR. Fresh resin composite cylinders were built up using silicone molds (hole: 1.5 mm high x 1.5 mm diameter) positioned over the aged plates. Half of the SBS samples were stored in distilled water for 24 hours and loaded until failure, while the other half were stored for 1 year before being tested. Data were submitted to two-way analysis of variance and post-hoc Tukey Test (preset alpha of 0.05). Positive Control, SAN+PLA+SIL+HBR and PLA+SIL+HBR groups presented higher SBS means at the 24 hour evaluation. After 1 year of water storage, all groups demonstrated significant SBS reduction, with the SAN+PLA+SIL+HBR group presenting the highest SBS. Resin plasma treatment in combination with other surface treatments can improve the SBS of composite repairs after one year of water storage. The SBS of the composite repair was not stable over time regardless of the surface treatment.

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.

Effect of Argon Plasma Treatment on Surface-Treated Titanium

This work compares the consequence of argon bombardment plasma treatment on sandblasted large-grit, acid-etched (SLA) and hydroxyapatite (HA) treated titanium surface. Titanium disc specimens were distributed into two groups depends on the surface treatment (SLA, HA). The SLA and HA-coated surfaces were further subdivided according to non-plasma and plasma treatments. An argon plasma treatment was done at ambient temperature under vacuum. The specimens (surface treated) were subjected to surface analysis using field-emission scanning electron microscopy, a three-dimensional optical profiler, and X-ray photoelectron spectroscopy (XPS). Furthermore, contact angle examination was performed via the sessile drop technique.

Effects of argon plasma treatment on the osteoconductivity of bone grafting materials.

The osteoconductive properties of bone grafting materials represent one area of research for the management of bony defects found in the fields of periodontology and oral surgery. From a physico-chemical aspect, the wettability of the graft has been demonstrated to be one of the most important factors for new bone formation. It is also well-known that argon plasma treatment (PAT) and ultraviolet irradiation (UV) may increase the surface wettability and, consequently, improve the regenerative potential of the bone grafts. Therefore, the aim of the present in vitro study was to evaluate the effect of PAT and UV treatment on the osteoconductive potential of various bone grafts. The following four frequently used bone grafts were selected for this study: synthetic hydroxyapatite (Mg-HA), biphasic calcium phosphate (BCP), cancellous and cortical xenogenic bone matrices (CaBM, CoBM). Sixty-six serially numbered disks 10 mm in diameter were used for each graft material and randomly assigned to the following three groups: test 1 (PAT), test 2 (UV), and control (no treatment). Six samples underwent topographic analysis using SEM pre- and post-treatments to evaluate changes in surface topography/characteristics. Additionally, cell adhesion and cell proliferation were evaluated at 2 and 72 h respectively following incubation in a three-dimensional culture system utilizing a bioreactor. Furthermore, the effects of PAT and UV on immune cells were assessed by measuring the viability of human macrophages at 24 h. The topographic analysis showed different initial morphologies of the commercial biomaterials (e.g., Mg-HA and BCP showed flat morphology; BM samples were extremely porous with high roughness). The surface analysis following experimental treatments did not demonstrate topographical difference when compared with controls. Investigation of cells demonstrated that PAT treatment significantly increased cell adhesion of all 4 evaluated bone substitutes, whereas UV failed to show any statistically significant differences. The viability test revealed no differences in terms of macrophage adhesion on any of the tested surfaces. Within their limitations, the present results suggest that treatment of various bone grafting materials with PAT appears to enhance the osteoconductivity of bone substitutes in the early stage by improving osteoblast adhesion without concomitantly affecting macrophage viability. Treatment of bone grafts with PAT appears to result in faster osseointegration of the bone grafting materials and may thus favorably influence bone regeneration.

Cytocompatibility of Titanium, Zirconia and Modified PEEK after Surface Treatment Using UV Light or Non-Thermal Plasma.

A number of modifications have been developed in order to enhance surface cytocompatibility for prosthetic support of dental implants. Among them, ultraviolet (UV) light and non-thermal plasma (NTP) treatment are promising methods. The objective of this study was to compare the effects of UV light and NTP on machined titanium, zirconia and modified polyetheretherketone (PEEK, BioHPP) surfaces in vitro. Machined samples of titanium, zirconia and BioHPP were treated by UV light and NTP of argon or oxygen for 12 min each. Non-treated disks were set as controls. A mouse fibroblast and a human gingival fibroblast cell line were used for in vitro experiments. After 2, 24 and 48 h of incubation, the attachment, viability and cytotoxicity of cells on surfaces were assessed. Results: Titanium, zirconia and BioHPP surfaces treated by UV light and oxygen plasma were more favorable to the early attachment of soft-tissue cells than non-treated surfaces, and the number of cells on those treated surfaces was significantly increased after 2, 24 and 48 h of incubation (p < 0.05). However, the effects of argon plasma treatment on the cytocompatibility of soft tissue cells varied with the type of cells and the treated material. UV light and oxygen plasma treatments may improve the attachment of fibroblast cells on machined titanium, zirconia and PEEK surfaces, that are materials for prosthetic support of dental implants.

Biological Effects of Plasma-Based Graphene Oxide Deposition on Titanium

This study was performed to investigate the effects of argon plasma treatment under atmospheric pressure at room temperature on the cytotoxicity and antimicrobial effects of the graphene oxide layer on titanium. Plasma treatment of the graphene oxide coating on a nonthermal atmospheric-pressure plasma device was performed. Raman spectrum analysis confirmed that graphene oxide was successfully coated on the surface and AFM analysis confirmed that this coating affected the surface roughness. X-ray photoelectron spectroscopy (XPS), Alizarin Red S staining for cell differentiation, and Raman and atomic force microscopy (AFM) analyses were performed for the deposited surface. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was performed to confirm the biocompatibility of the plasma-treated and bare titanium specimens. The biofilm formation test usingStreptococcus mutans(S. mutans) was performed to examine potential antimicrobial effects. XPS analysis showed that with increasing plasma coating time, the carbon content of the surface decreased while that of oxygen increased. Alizarin Red S staining showed that the cell differentiation was promoted by the deposition of the graphene oxide. The graphene oxide on Ti significantly affected an osteoblast cell differentiation for bone growth, and no significant differences in antimicrobial effects were observed.

Effect of Argon Plasma Surface Treatment on Bond Strength of Resin Composite Repair.

This study evaluated the effect of argon plasma treatment (PLA) and its combination with sandblasting (SAN), silanization (SIL), and hydrophobic bonding resin (HBR) application on the micro-shear bond strength of water-aged restorative resin composite to a newly placed composite, simulating restoration repair. Forty-five light-cured composite plates (20-mm long × 20-mm wide × 4-mm thick) were fabricated using a hybrid composite and stored at 37°C in distilled water for six months. The aged composite surfaces were treated according to the following experimental groups, varying both treatment and order of application: 1) SAN + SIL + HBR (control), 2) SAN + PLA for 30 seconds + SIL + HBR, 3) SAN + SIL + PLA + HBR, 4) PLA + SIL + HBR, 5) PLA + SIL, 6) PLA + HBR, 7) SIL + PLA + HBR, 8) SIL + PLA, and 9) PLA. After the surface treatments, four fresh resin composite cylinders (1.5-mm high × 1.5-mm diameter) of the same composite were built on each aged composite surface using a silicone mold. After water storage for 24 hours or one year, the specimens were submitted to shear bond strength testing. Data were statistically analyzed by two-way analysis of variance and Tukey's test (5%). Groups 1, 2, and 4 presented significantly higher bond strength means at 24 hours, although group 4 did not differ from group 7. Groups 5, 8, and 9 demonstrated significantly lower means than the other groups. Even though groups 1 and 2 had a significant bond strength reduction after 1 year, they still demonstrated higher bond strength at one year of storage. While PLA application combined with surface treatment methods demonstrated high bond strength results, this treatment alone was not as beneficial as other methods that included SAN, SIL and HBR.

Effect of argon plasma treatment on hydrophilic stability of nanofiber webs

ABSTRACTThis paper provides a comprehensive analysis of microwave‐induced low‐vacuum argon plasma treatment effects on the hydrophilic stability of various polymeric nanofiber webs. After plasma modification, samples are kept dry at room temperature in a dark place for the experiments, and the wettability of the nanofibers is improved by plasma treatment. The stability of the plasma‐treated hydrophilic nanofiber webs is observed for 55 days using water contact angle measurements. Different polymeric nanofiber webs show different stability. Based on the contact angle measurements, the surface starts to lose hydrophilicity during the first week after plasma treatment. The structural changes are examined by pore size measurements, scanning electron microscopy, and Fourier transform infrared spectroscopy. Two of the selected nanofiber webs are used as microfilters for separation of oily wastewater with a cross‐flow separation unit to measure the effect of the plasma treatment under wastewater. The permeability and selectivity of the plasma‐treated and untreated samples are compared. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46751.

Exploring the Effects of Argon Plasma Treatment on Plasmon Frequency and the Chemiresistive Properties of Polymer-Carbon Nanotube Metacomposite.

Metacomposites, composite materials exhibiting negative permittivity, represent an opportunity to create materials with depressed plasmon frequency without the need to create complex structural geometries. Although many reports exist on the synthesis and characterizations of metacomposites, very few have ventured into exploring possible applications that could take advantage of the unique electrical properties of these materials. In this article, we report on the chemiresistive properties of a polymer-CNT metacomposite and explore how these are affected by Argon plasma treatment.

Effect of argon plasma treatment on the output performance of triboelectric nanogenerator

Physical and chemical properties of the polymer surface play great roles in the output performance of triboelectric nanogenerator (TENG). Specific texture on the surface of polymer can enlarge the contact area and enhance the power output performance of TENG. In this paper, polydimethylsiloxane (PDMS) films with smooth and micro pillar arrays on the surface were prepared respectively. The surfaces were treated by argon plasma before testing their output performance. By changing treatment parameters such as treating time and plasma power, surfaces with different roughness and their relationship were achieved. The electrical output performances of the assembled TENG for each specimen showed that argon plasma treatment has a significant etching effect on the PDMS surface and greatly strengthen its output performance. The average surface roughness of PDMS film increases with the etching time from 5mins to 15 mins when the argon plasma power is 60W. Nevertheless, the average surface roughness is inversely proportional to the treatment time for the power of 90W. When treated with 90W and 5mins, many uniform micro pillars appeared on the both PDMS surface, and the output performance of the TENG for plasma treated smooth surface is 2.6 times larger than that before treatment. The output voltage increases from 42V to 72V, and the short circuit current increases from 4.2μA to 8.3μA after plasma treatment of the micro pillar array surface. However, this plasma treatment has time-efficient due to the hydrophobic recovery property of Ar plasma treated PDMS surface, both output voltage and short circuit current decrease significantly after 3 months.

Structural characterization of the interface structure of amorphous silicon thin films after post-deposition argon or hydrogen plasma treatment

The interfaces in silicon thin film solar cells and silicon heterojunction solar cells are considered to be very important for the solar cell conversion efficiency. This work studies the interface properties of hydrogenated amorphous silicon thin films deposited on crystalline silicon wafers after post-deposition hydrogen plasma treatment (HPT) or argon plasma treatment (APT). The investigation extends our previous study by examining the structural changes resulting from the post-deposition plasma treatment on silicon thin film solar cells. We analyzed the ellipsometry and infrared spectra of our samples to gain a deeper understanding of the fundamental plasma treatment effects. By using post-deposition APT and HPT, we were able to reduce the material stress and improve the structure of these layers. Our results show that APT yields a more compact material with fewer voids and less distinct localized tail states. We discuss the effect of APT and HPT on the most crucial interface in silicon heterojunction solar cells, the i-a-Si:H/c-Si interface. We propose to introduce APT as a post-deposition process step in the fabrication of silicon heterojunction solar cells.

Rf-sputtered aluminium doped zinc oxide films: Enhanced damp heat stability by means of plasma etching treatment

Abstract ZnO:Al films, obtained by RF-sputtering and textured by wet etching, have been subjected to argon plasma etching treatment in order to stabilize their electrical properties over time, being well known the electrical degradation of these transparent conductive films when exposed to air. Specifically focused on photovoltaic application as front electrode, the effect of argon plasma treatment on long-term electrical stability of ZnO:Al thin film was monitored by performing damp heat degradation cycles in environmental test chamber. There was evidence for strong slowdown of electrical degradation when ZnO surface had been subjected to Ar plasma treatment. Different etching times have been used and it has been observed that surface modification induced by plasma treatment gave its more pronounced beneficial effect after the first 10 min of the process. In particular, for no-plasma treated samples the carrier mobility worsening is about three times larger than that related to Ar-treated samples after long-lasting aging test. The stabilization mechanism of the electrical properties was investigated by studying the main modifications of the plasma etched materials in terms of optical, chemical, morphological and structural properties. Structural analysis revealed that crystalline rearrangement occurs down to 30 nm depth below the plasma treated film surface, where a thin nanocrystalline layer forms. PL analysis revealed a different distribution of deep defect centres for plasma treated film surface compared to untreated one. In particular, donor-like lattice defects (Vo and Zni) decreased whereas Vzn defects became predominant. Crystalline rearrangement and change of type and/or amount of deep defect centres inside the plasma modified top layer have been hypothesized as responsible for the enhancement of the electrical stability.

Effect of Argon Plasma Treatment on Tribological Properties of UHMWPE/MWCNT Nanocomposites.

Ultra-high molecular weight polyethylene (UHMWPE) is widely used in artificial joints in the replacement of knee, hip and shoulder that has been impaired as a result of arthritis or other degenerative joint diseases. The UHMWPE made plastic cup is placed in the joint socket in contact with a metal or ceramic ball affixed to a metal stem. Effective reinforcement of multi-walled carbon nanotubes (MWCNTs) in UHMWPE results in improved mechanical and tribological properties. The hydrophobic nature of the nanocomposites surface results in lesser contact with biological fluids during the physiological interaction. In this project, we investigate the UHMWPE/MWCNTs nanocomposites reinforced with MWCNTs at different concentrations. The samples were treated with cold argon plasma at different exposure times. The water contact angles for 60 min plasma-treated nanocomposites with 0.0, 0.5, 1.0, 1.5, and 2.0 wt % MWCNTs were found to be 55.65°, 52.51°, 48.01°, 43.72°, and 37.18° respectively. Increasing the treatment time of nanocomposites has shown transformation from a hydrophobic to a hydrophilic nature due to carboxyl groups being bonded on the surface for treated nanocomposites. Wear analysis was performed under dry, and also under biological lubrication, conditions of all treated samples. The wear factor of untreated pure UHMWPE sample was reduced by 68% and 80%, under dry and lubricated conditions, respectively, as compared to 2 wt % 60 min-treated sample. The kinetic friction co-efficient was also noted under both conditions. The hardness of nanocomposites increased with both MWCNTs loading and plasma treatment time. Similarly, the surface roughness of the nanocomposites was reduced.

Carrier collection losses in interface passivated amorphous silicon thin-film solar cells

In silicon thin-film solar cells the interface between the i- and p-layer is the most critical. In the case of back diffusion of photogenerated minority carriers to the i/p-interface, recombination occurs mainly on the defect states at the interface. To suppress this effect and to reduce recombination losses, hydrogen plasma treatment (HPT) is usually applied. As an alternative to using state of the art HPT we apply an argon plasma treatment (APT) before the p-layer deposition in n-i-p solar cells. To study the effect of APT, several investigations were applied to compare the results with HPT and no plasma treatment at the interface. Carrier collection losses in resulting solar cells were examined with spectral response measurements with and without bias voltage. To investigate single layers, surface photovoltage and X-ray photoelectron spectroscopy (XPS) measurements were conducted. The results with APT at the i/p-interface show a beneficial contribution to the carrier collection compared with HPT and no plasma treatment. Therefore, it can be concluded that APT reduces the recombination centers at the interface. Further, we demonstrate that carrier collection losses of thin-film solar cells are significantly lower with APT.

The effect of argon plasma treatment on the permeation barrier properties of silicon nitride layers

In this work we produce and study silicon nitride (SiNx) thin films deposited by Hot Wire Chemical Vapor Deposition (HW-CVD) to be used as encapsulation barriers for flexible organic photovoltaic cells fabricated on polyethylene terephthalate (PET) substrates in order to increase their shelf lifetime. We report on the results of SiNx double-layers and on the equivalent double-layer stack where an Ar-plasma surface treatment was performed on the first SiNx layer. The Ar-plasma treatment may under certain conditions influences the structure of the interface between the two subsequent layers and thus the barrier properties of the whole system. We focus our attention on the effect of plasma treatment time on the final barrier properties. We assess the encapsulation barrier properties of these layers, using the calcium degradation test where changes in the electrical conductance of encapsulated Ca sensors are monitored with time. The water vapor transmission rate (WVTR) is found to be ~3×10−3g/m2·day for stacked SiNx double-layer with 8min Ar plasma surface treatment.

Effect of Argon Plasma Pretreatment on Tensile Bond Strength of a Silicone Soft Liner to Denture Base Polymers

This study evaluated the effect of argon plasma treatment on tensile bonding of heat-cured and auto-polymerized acrylic resins prior to the processing of a silicone soft liner. Both types of polymethylmethacrylate (PMMA) resins were treated with argon plasma for 1 min or 10 min (n = 5). A control group, including untreated resin specimens, was also formed. After processing of the soft liner, the specimens were deflasked and stored dry for 24 h, and they were then subjected to tensile bond strength testing. In order to see the plasma effect on the resin surface chemistry, representative specimens were analysed by XPS. Highest tensile bond strengths were observed in the 1-min exposure group for each resin, and 10-min exposure yielded the lowest bond strength likely due to the damaging effect of the plasma treatment. XPS analysis showed that the O/C ratios increased greatly in treated samples and that the binding energy values were not significantly changed.

Optical Emission Spectroscopy Study and 3-D Surface Characterization of Silicone Rubber Exposed to Different Argon RF Plasma Powers

The present study was undertaken to investigate the effect of argon plasma treatment on the extent of Foley catheter surface modification. Foley catheter (flexible tube made of silicone rubber, used for urinary catheterization) surface was treated at different argon (Ar) RF plasma powers. The surface modification was assessed by measurement of contact angle. Contact angle study shows decrease in contact angle and increase in surface free energy shows more polar group incorporation at low power plasma treatment. Atomic force microscopy (AFM) revealed an increased average surface roughness proportional to plasma power. Optical emission spectroscopy (OES) shows various states of argon causing surface modification.

Effects of argon plasma treatment on the adhesion property of ultra high molecular weight polyethylene (UHMWPE) textile

In this investigation, effects of argon plasma on surface modification of ultra high molecular weight polyethylene (UHMWPE) textile were studied. After argon plasma treatment, the peeling test of UHMWPE textile/adhesive (PU_T01) composites were measured by ISO 10339:2003 and then observed the morpho-surface composites by SEM analysis. In addition, the contact angle of UHMWPE textile by argon plasma was also measured. Results showed that the peel strength of UHMWPE textile/adhesive (PU_T01) composites was increased from 0.6kgf/in to 4.6kgf/in as argon plasma treatment with treated power of 40W and treated time of 5min. From SEM observation, the surface of UHMWPE textile was introduced the number of anchors after argon plasma treatment. After plasma treatment, the UHMWPE react with adhesive. And the contact angle on surface of UHMWPE textile was decreased from 80° to 28°.