Structural Analysis of Kevlar Fabric Treated with Oxygen Plasma

2020 ◽  
Vol 28 (3(141)) ◽  
pp. 79-83
Author(s):  
Talita Galvão Targino ◽  
Rayane Dantas da Cunha ◽  
João Freire de Medeiros Neto ◽  
Ricardo Alex Dantas da Cunha ◽  
Thércio Henrique de Carvalho Costa ◽  
...  

The purpose of this work was to study the effects of low-pressure oxygen plasma treatment on the surface characteristics of kevlar fabric. For comparison purposes, samples treated with oxygenated plasma were prepared and characterised under different experimental conditions, i.e. a treatment time variation of 10, 30 and 60 minutes under a constant pressure of 4 mBar, using a pulsed current source. We analysed the effects of chemical and physical changes to the surface of the material aiming at improved hydrophilicity attributed to the formation of roughness on the surface of fibres, thus obtaining optimal parameters for future works. Changes in the chemical composition of the surface as well as in the superficial roughness of fibres before and after treatment were determined by FTIR, TGA, XRD and wettability testing. SEM was used as a complementary technique to monitor the changes triggered by the procedures using oxygen plasma.

2012 ◽  
Vol 629 ◽  
pp. 19-24 ◽  
Author(s):  
Cheng Yu Wang ◽  
Fei Shi ◽  
Shi Hong Pang ◽  
Chun Sheng Ren ◽  
Ying Tao ◽  
...  

Coatings such as Cr, Ni, Ti, and SiO2/SnO2 on solar-control and low-emissivity (low-E) glasses are commonly used in the energy efficient glass windows. However, coloring in the re-manufactured glass panels using recycled window glasses resulting from the coatings reduces the glass transparency significantly. Traditional ways to remove coatings by manual wheels and pneumatic removal machines are labor intense and slow processes. In this study a new way to remove the coatings on recycled coated glasses was investigated. The Ultra Violet/Visible/Infrared (UV/VIS/IR) spectra and Secondary Electron Microscope (SEM) pictures were taken before and after 30s. atmospheric pressure oxygen plasma treatments. It was confirmed that the atmospheric oxygen plasma treatment is a fast, efficient, and low pollution way to remove the coatings before the remanufacture of recycled glasses. Other than the physical sputtering off the coatings from the plasma, there are many excited oxygen species in the plasma which effectively react to the coating and the products are then removed.


Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 599 ◽  
Author(s):  
Zhenhua Sun ◽  
Yanfen Zhou ◽  
Wenyue Li ◽  
Shaojuan Chen ◽  
Shihua You ◽  
...  

Direct electroless silver plating of para-aramid (PPTA) is difficult due to its extremely low surface chemical energy. In order to facilitate the deposition of silver nanoparticles and to enhance the washing fastness, oxygen plasma treatment and dopamine modification were conducted before silver plating of PPTA fibers. Various techniques including scanning electron microscopy (SEM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffractometer (XRD) and thermogravimetric analyzer (TGA) were used to characterize the surface morphology, chemical composition and thermal stability of the silver-plated PPTA fibers. Electrical resistance and silver content of the silver-coated PPTA fibers before and after standard washing were also studied. The results showed that silver nanoparticles were successfully coated onto the surface of PPTA fibers with and without plasma treatment, but the coating continuity and the electrical conductivity of the silver-coated PPTA fibers were greatly enhanced with the assistance of plasma treatment. It was also demonstrated that the washing fastness of silver-coated PPTA fibers was improved after plasma treatment as indicated by electrical resistance and continuity of the silver nanoparticles after various washing cycles. It was found that the electrical resistance of plasma-treated PPTA-PDA/Ag fibers prepared at an AgNO3 concentration of 20 g/L reached 0.89 Ω/cm and increased slightly to 0.94 Ω/cm after 10 standard washing cycles. The silver-coated PPTA fibers also showed stable electrical conductivity under 250 repeated stretching-releasing cycles at a strain of 3%.


2011 ◽  
Vol 1336 ◽  
Author(s):  
Amirhasan Nourbakhsh ◽  
Mirco Cantoro ◽  
Tom Vosch ◽  
Geoffrey Pourtois ◽  
Johan Hofkens ◽  
...  

ABSTRACTWe investigate the structural, optical and electrical properties of single-layer graphene exposed to oxygen plasma treatment. We find that the pristine semimetallic behavior of graphene disappears upon plasma treatment, in favour of the opening of a bandgap and the featuring of semiconducting properties. The metal-to-semiconductor transition observed appears to be dependent on the plasma treatment time. The semiconducting behavior is also confirmed by photoluminescence measurements. The opening of a bandgap in graphene is explained in terms of graphene surface functionalization with oxygen atoms, bonded as epoxy groups. Ab initio calculations of the density of states show more details about the oxygen–graphene interaction and its effects on the graphene optoelectronic properties, predicting no states near the Fermi level at increasing epoxy group density. The structural changes are also monitored by Raman spectroscopy, showing the progressive evolution of the sp2 character of pristine graphene to sp3, due to the lattice decoration with out-of-plane epoxy groups.


1995 ◽  
Vol 397 ◽  
Author(s):  
Jae-Ik Woo ◽  
Sang-Gul Lee ◽  
Dae-Gyu Moon ◽  
Chan-Hee Hong ◽  
Hoe-Sup Soh

ABSTRACTOxygen plasma treatment was performed on the excimer laser annealed poly-Si surface, followed by gate oxide deposition with low pressure chemical vapor deposition (LPCVD) in order to control the threshold voltage of excimer laser annealed poly-Si thin film transistors (TFTs).Threshold voltages of n-channel TFTs increase from 0.4 to 2.8 V by varying the treatment time from 0 to 7 min. It is shown the effective charge density increased toward negative direction with increase of the treatment time.In addition to the increase of threshold voltage, the oxygen plasma treatment on the Si surface led to an increase in the deposition rate of LPCVD oxide films with an apparent reduction of carbon around the interface between gate insulator and poly-Si film after oxygen plasma treatment.


2008 ◽  
Vol 373-374 ◽  
pp. 430-433 ◽  
Author(s):  
Ping Chen ◽  
Jing Wang ◽  
Cheng Shuang Zhang ◽  
Chun Lu ◽  
Zhen Feng Ding ◽  
...  

Armos fiber (F-12 aramid fiber in paper) was provided with broad application foreground as reinforcement material for advanced composites in aviation and spaceflight field, due to its outstanding properties, such as high modulus, high strength, high temperature resistance, erosion resistance and so on. However, the exertion of property was still limited by slippery surface, low surface energy and weak interfacial adhesion performance. In this study, the effects of oxygen plasma treatment time on polar functional groups introduced onto the fiber surface, surface free energy and surface topographic images were discussed by X-ray photoelectron spectroscopy (XPS) analysis, dynamic contact angle analysis system (DCA) and atomic force microscopy (AFM), respectively. It was found that the content of oxygen element and polar functional groups on fiber surface were all increased obviously after oxygen plasma treatment. The content of oxygen element on surface for untreated F-12 aramid fiber was 11.13%, while it increased to 15.20% after oxygen plasma treatment for 10 min; The content of polar functional groups on surface for untreated F-12 aramid fiber was 28.14%, while it increased to 38.11% after oxygen plasma treatment for 10 min. The polar component (γp) of fiber surface energy increased sharply from 6.82 mN/m to 36.68 mN/m after 10 min plasma treatment, the total surface free energy was increased from 46.26 mN/m to 64.66 mN/m.The results indicated that oxygen plasma treatment had introduced a large amount of reactive functional groups onto the fiber surface, and these groups can form together as covalent bonding to improve the surface wettability and increase the surface energy of fibers. At the same time, oxygen plasma treatment was able to generate a mass of bulges and grooves on F-12 aramid fiber surface, which had an active effect on increasing the chemical bond and mechanical function between fiber and resin and enhancing the interfacial adhesion performance of composite. The fiber surface grooves had been increased with the time prolonging before 10 min while decreased after 10 min, the results maybe relate to partial organic on fiber surface melting. It had an adverse effect on the interfacial adhesion properties of composite. Therefore, the optimum plasma treatment time was between 5 min and 10 min.


2017 ◽  
Vol 868 ◽  
pp. 236-241
Author(s):  
Da Zhi Wang ◽  
Li Feng ◽  
Yun Long Wei ◽  
Jia Chang Cao ◽  
Xin Yu Chen ◽  
...  

In this paper, graphene nanosuspension was spray deposited using electrohydrodynamic atomization (EHDA) technique, and the polydimethylsiloxane (PDMS) was used as the substrate during the EHDA process. The effect of the PDMS substrate before and after oxygen plasma treatment on the characteristics of EHDA was examined. A cone-jet mode of the EHDA of graphene nanosuspension was obtained using the oxygen plasma treated PDMS substrate. In addition graphene films were deposited on the oxygen plasma treated PDMS at different working distances. The lowest sheet resistance of the graphene films is 127Ω·sq-1. Furthermore, graphene lines at the range of 30μm-170μm were fabricated using the template assisted EHDA deposition method.


2013 ◽  
Vol 781-784 ◽  
pp. 2605-2608 ◽  
Author(s):  
Wen Yu Wang ◽  
Xin Jin ◽  
Bo Wang ◽  
Li Na Bian

Ultra-high-molecular-weight polyethylene (UHMWPE) fibers were treated by low temperature oxygen-plasma. The effects of oxygen-plasma treatment time on the properties of UHMWPE have been investigated. The wetting ability and roughness were increased significantly after the treatment. While, the tensile strength at break of UHMWE fibers were decreased with the treatment time. The optimum plasma treatment time is 2min.


1998 ◽  
Vol 18 (1-2) ◽  
pp. 49-62 ◽  
Author(s):  
Seung-Goo Lee ◽  
Tae-Jin Kang ◽  
Tae-Ho Yoon

Abstract The surface area change of UHMWPE fibers which underwent oxygen plasma treatment was measured as a function of plasma power and plasma treatment time. The interfacial adhesion of oxygen plasma treated UHMWPE fibers was evaluated via micro-droplet test and double cantilever beam test Surface area increased with plasma treatment time at 30 and 60W, but showed a maximum at 100 and 150W. The interfacial adhesion of UHMWPE fibers to vinylester resin exhibited the same trend as the surface area. SEM analysis revealed that oxygen plasma treatment roughened UHMWPE fibers by forming micro-pores leading to increased surface area. However, 1S0W plasma treatment led to degradation of the fibers and thus resulted in failure within the fiber surface layers, producing ribbon-like strips of fiber.


2017 ◽  
Vol 13 ◽  
pp. 130
Author(s):  
Jan Trejbal ◽  
Tereza Horová ◽  
Zdeněk Prošek

The aim of this work is to describe bonding properties between surface treated polymer fibers and a cement matrix. In order to increase an interaction between the matrix and fiber surfaces, two fiber types having approx. 0.5 mm in diameter were modified by mean of oxygen plasma treatment. Surface physical changes of treated fibers were examined using SEM morphology observation and interfacial adhesion mechanical tests. The principle of mechanical tests rested on a single fiber pulling out from the matrix (cement paste, CEM I 42.5 R, w/c 0.4). The embedded length was equal to 50 % of original fiber length (50 mm), where the fiber free-end displacement and force resisting to the displacement were monitored. It was pointed out that interfacial shear stress needed to break the bond between the modified fibers and the matrix increased almost by 15–65 % if compared to reference fibers. When the fiber free-end displacement reached to 3.5 mm, the shear strength increased almost twice.


2007 ◽  
Vol 119 ◽  
pp. 159-162 ◽  
Author(s):  
Soo Jin Park ◽  
Jin Seok Oh ◽  
Jae Rock Lee ◽  
Kyong Yop Rhee

In this work, effects of the oxygen plasma on surface characteristics of carbon fibers were investigated in impact strengths of the carbon fibers-reinforced composites. The surface properties of the carbon fibers were determined by acid-base values, FT-IR, and X-ray photoelectron spectroscopy (XPS). Also, the mechanical properties of the composites were studied in impact strength measurements. As experimental results, the O1S/C1S ratio of the carbon fiber surfaces treated by oxygen plasma was increased compared to that of untreated ones, possibly due to development of oxygen-containing functional groups. The mechanical properties of the composites, including impact strength had been improved in the oxygen plasma on fibers. These results indicate that the oxygen plasma can lead to an increase in the adhesion between fibers and matrix in a composite system.


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