Effect of Glycerol Coating on the Atmospheric Pressure Plasma Treatment of UHMWPE Fibers

In order to investigate how coatings of glycerol affects atmospheric pressure plasma treatment, ultra high molecular weight polyethylene (UHMWPE) fibers were first pretreated with 0.2 and 0.6 mol/l glycerol solutions, respectively, and then were modified by an atmospheric pressure plasma jet (APPJ) using helium as the carrier gas with a flow rate of 20 l/min, discharge power of 30 W and a radio frequency of 13.56 MHz. After the plasma treatment, scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis revealed that the glycerol coated-APPJ treated samples possessed smoother surface than the APPJ directly treated samples. The X-ray photoelectron spectroscopy (XPS) analysis indicated that the changed content of oxygen containing groups on the surface of the glycerol coated groups compared with the non-glycerol coated group was mainly due to the remaining glycerol on the fiber surfaces. The water contact angle test revealed that the wettability of the glycerol coated-APPJ treated fibers decreased slightly in comparison with the APPJ directly treated fibers. Furthermore, the microbond pull-out test indicated that the interfacial bonding of the fiber to epoxy resin decreased when the fiber was pretreated with glycerol before plasma treatment. Therefore, it was concluded that the presence of glycerol on fiber surface weakened the effectiveness of APPJ treatment of UHMWPE fibers in improving the interfacial bonding to epoxy. This was mainly attributed to the consumption of plasma energy in etching the glycerol layer on the fiber surface and a weak interfacial layer due to the presence of residual glycerol.     

Atmospheric continuous cold plasma treatment: Thermal and hydrodynamical diagnostics of a plasma jet pilot unit

An atmospheric pressure plasma jet (APPJ) for continuous treatment of polymeric films and textile materials was investigated to characterize its thermal, hydrodynamic and chemical features. The operative variables of the plasma jet equipment are: gas flow rate and composition, electrical power to the plasma generator and fabric velocity. A diagnostic evaluation of the equipment was carried out to improve the treatment homogeneity and generate an effective feedback for scale-up. The cross profile of gas temperature and velocity, the fabric temperature and concentration transitory in the gas system generated by a reverse step of oxygen were determined. These measurements showed that the original prototype configuration required a better gas distribution to fully demonstrate its potentiality to functionalize textiles. The surface modifications induced by plasma were detected by processing wool fabrics and by evaluating the treatment benefit on dyeing.     

Surface modification of nylon 6 films treated with an He/O2 atmospheric pressure plasma jet

To investigate the effect of the gas composition of the plasma treatment on the surface modification of an atmospheric pressure plasma jet (APPJ), nylon 6 films were treated with APPJ with pure helium (He), He + 1% oxygen (O₂), and He + 2% O₂, respectively. Atomic force microscopy showed increased surface roughness, whereas X‐ray photoelectron spectroscopy revealed increased oxygen contents after the plasma treatments. The plasma‐treated samples had lower water contact angles and higher T‐peel strengths than the control. The addition of a small amount of O₂ to the He plasma increased the effectiveness of the plasma treatment in the polymer surface modification in terms of surface roughness, surface oxygen content, etching rate, water contact angle, and bonding strength. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Surface modification of ultra high modulus polyethylene fibers by an atmospheric pressure plasma jet

To improve their adhesion properties, ultra high modulus polyethylene (UHMPE) fibers were treated by an atmospheric pressure helium plasma jet (APPJ), which was operated at radio frequency (13.56 MHz). The surface properties of the fibers were investigated by X‐ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and contact angle measurement. The surface dyeability improvement after plasma treatments was investigated using laser scanning confocal microscopy (LSCM). The adhesion strengths of the fibers with epoxy were evaluated by microbond tests. In addition, the influence of operational parameters of the plasma treatment including power input and treatment temperature was studied. XPS analysis showed a significant increase in the surface oxygen content. LSCM results showed that the plasma treatments greatly increased fluorescence dye concentrations on the surface and higher diffusion rate to the fiber center. The tensile strength of UHMPE fiber either remained unchanged or decreased by 10–13.6% after plasma treatment. The contact angle exhibited a characteristic increase in wettability, due to the polar groups introduced by plasma treatment. The microbond test showed that the interfacial shear strengths (IFSS) increase significantly (57–139%) after plasma treatment for all groups and the optimum activation is obtained at 100°C and 5 W power input. SEM analysis showed roughened surfaces after the plasma treatments. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

常压等离子体改善合成纤维吸湿性的研究

用氦气作为等离子体的气体源、对涤纶、锦纶6、高强度聚乙烯纤维,Twaron 1000芳纶4种合成纤维进行常压等离子体处理,改善纤维的吸湿性能。结果表明:常压等离子体处理,对涤纶和锦纶6的表面有一定的刻蚀作用,但对高强度聚乙烯纤维、Twaron 1000芳纶的表面没有明显影响;经常压等离子体处理后,合成纤维表面氧、氮有所增加,吸湿性能得到提高,强度没有显著变化。     

The Impact of Nitrogen Plasma Treatment upon the Physical-Chemical and Dyeing Properties of Wool Fabric

Pretreatment of wool fabric with low-temperature plasma (LTP) as an eco-friendly process was tested. The impact of plasma-treatment parameters on the surface morphology, physical-chemical, and dyeing properties of wool using anionic dyes were investigated. The LTP-treatment resulted in a dramatic improvement in fabric hydrophilicity and wettability, the removal of fiber surface material, and creation of new active sites along with improved initial dyeing rate. The nature of the plasma gas governed the final exhaustion percentage of the used acid dyes according to the following descending order: nitrogen plasma > nitrogen/oxygen (50/50) plasma > oxygen plasma > argon plasma ≥ control. Prolonging the exposure time up to 20 minutes resulted in a gradual improvement in the extent of exhaustion. Increasing the ageing period up to 100 hours resulted in a slight decrease in the extent of acid dye uptake. Increasing the salt concentration up to 5 g/L and the dyeing temperature up to 95°C resulted in an enhancement in the extent of exhaustion. The extent of improvement in dye bath exhaustion, using low temperature nitrogen plasma (LTNP)-treatment, was determined by the nature of the anionic dyes.     

Influence of environmental moisture on atmospheric pressure plasma jet treatment of ultrahigh-modulus polyethylene fibers

One of the main differences between low-pressure and atmospheric-pressure plasma treatments is that there is little moisture involved in the low-pressure plasma treatment, although moisture could exist at the wall of the vacuum chamber or react with the substrate after plasma treatment, while in the atmospheric-pressure plasma treatment moisture exists not only in the environment but also in any hygroscopic substrate. In order to investigate the influence of environmental moisture on the effect of atmospheric pressure plasma treatment, ultra-high-modulus polyethylene (UHMPE) fibers were treated using an atmospheric-pressure plasma jet (APPJ) with 10 l/min helium gas-flow rate, treatment nozzle temperature of 100°C and 5 W output power. The plasma treatments were carried out at three different relative humidity levels, namely 5, 59 and 100%. After the plasma treatments, the surface roughness increased while the water-contact angle decreased with increasing relative humidity. The number of oxygen containing groups increased as the environmental moisture content increased. The interfacial shear strength of the UHMPE fiber/epoxy system was significantly increased after the plasma treatments, but the moisture level in the APPJ environment did not have a significant influence on the adhesion properties. In addition, no significant difference in single fiber tensile strength was observed after the plasma treatments at all moisture levels. Therefore, it was concluded that the environmental moisture did not significantly influence the effect of atmospheric-pressure plasma treatment in improving interfacial bonding between the fiber and epoxy. The improvement of the interfacial shear strength for the plasma-treated samples at all moisture levels was mainly due to the increased surface roughness and increased surface oxygen and nitrogen contents due to the plasma etching and surface modification effect.     

常压等离子射流表面改性超高模量聚乙烯纤维

利用常压等离子射流(APPJ)方法对超高模量聚乙烯(UHMPE)纤维进行表面改性处理。研究了处理前后UHMPE纤维的力学性能、表面形貌、化学成分、表面粘结性能的变化。结果表明,常压等离子射流处理后,UHMPE纤维的强度未发生显著变化,纤维表面粗糙度增加,表面氧元素的含量增加,表面极性基团增加,纤维与环氧树脂之间的粘结性能得到显著的改善。     

Chemical modification of nylon 6 and polyester fabrics by ozone‐gas treatment

In a previous article, we reported on the ozone‐gas treatment of wool and silk fabrics in relation to the gas‐phase processing of textile fabrics. The treatment incorporated an oxygen element into the fiber surface and contributed to an increase in water penetration into the fabric. In this study, nylon 6 and polyester fabrics were treated with ozone gas in the same way as that of the wool and silk fabrics. The treatment incorporated much more oxygen into the fiber surface in the form of ? COH and ? COOH, as shown by electron spectroscopy for chemical analysis. Water penetration increased considerably with treatment, and the apparent dyeing rate and equilibrium dye uptake were also improved, especially for the polyester fabric, despite an increase in the crystallinity. Therefore, it seemed that the treatment brought about a change not only in the fiber surface but also in the internal structure of the fibers (the crystalline and amorphous regions) with regard to the dyeing behavior. Further, the mechanical characteristics of the ozone‐gas‐treated polyester and nylon 6 fabrics were measured with a Kawabata evaluation system apparatus. The shearing modulus and hysteresis widths increased with treatment, especially for the polyester fabric. Therefore, it was clear that the treatment caused a change in the fabric hand to crisp. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1344–1348, 2006     

Atmospheric-pressure plasma treatment of polyamide 6 composites for bonding with polyurethane

An atmospheric-pressure plasma jet (APPJ)-based surface treatment process was investigated for the structural (τ_B > 15 MPa) adhesive bonding of polyamide 6 (PA6) composites. The treated surfaces were examined by contact angle measurement, X-ray photoelectron spectroscopy, and atomic force microscopy (AFM). Additionally, the shear strengths of single lap specimens were determined as a function of different plasma intensities and polyurethane adhesives. Our results show that APPJ leads to an increase of the surface free energy, oxygen concentration, and number of functional groups. Furthermore, the topography of the surface was significantly modified by exposure to APPJ. AFM measurements show that special attention has to be paid to the intensity of the plasma treatment to avoid melting and flattening of the PA6 surface on the nanometer scale. With optimized multiple APPJ treatments, lap shear strength of 20 MPa was achieved for the first time for this material system, allowing the material system to be employed in future automobile applications.     

Influence of low‐temperature plasma conditions on wicking properties of PA/PU knitted fabric

Plasma surface treatment has been extensively applied in the textile industry for the modification of polymer materials. In this study low‐temperature plasma (LTP) is used for surface treatment of polyamide/polyurethane (PA/PU) knitted fabric. The envisaged plasma effect is an increase in the surface energy of the treated textile, leading toward improved hydrophilic properties. The knitted fabric was treated by LTP using three non polymerizing gases: oxygen, air, and carbon dioxide. After plasma treatment, wettability of samples was tested through their wicking properties measuring capillary rise after water bath contact. The PA/PU knitted fabric samples treated with different plasma gases exhibited different hydrophilic performances. The influence of plasma variables (discharge power, time, pressure) was investigated. Although the chemical characteristics of elastan (PU) and nylon (PA) threads are different, the study has demonstrated that plasma treatment can in the same time alter the surface‐wetting behavior of both the components of the knitted fabric. It was also shown how these treatments can be regulated to produce the desired level of hydrophilicity dependently on the request application. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Dyeing behaviors of ionic liquid treated wool

In this article, a new class of “green” solvent—ionic liquid (IL) was employed to improve the dyeability of wool. The physical and chemical properties of the IL‐treated wool, such as surface morphology, wettability, and tensile strength were first analyzed, and then the dyeing properties of IL‐treated wool were investigated in terms of dyeing rate, dyeing exhaustion at equilibrium, color depth, and color fastnesses. The scanning electron microscope (SEM) images showed eroded marks on IL‐treated wool fiber surfaces. The water contact angle of the fabric treated with IL at 100°C decreased from 118.6° to 106.4°. The tensile strength of IL‐treated wool fibers was slightly decreased when the treating temperature was less than 100°C. Dyeing kinetics experiments revealed that the IL treatments greatly increased initial dyeing rate, shortened half‐dyeing time, and time to reach dyeing equilibrium. The final exhaustion and color depth of IL‐treated wool were also increased accompanying with slightly decreased color fastness. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Aging of hydrophobized surfaces of ramie fibers induced by atmospheric pressure plasma treatment with ethanol pretreatment

In order to investigate hydrophilic recovery of hydrophobic treatment of cellulose fibers, ramie fibers are ethanol-pretreated followed by atmospheric pressure plasma jet (APPJ) treatment using helium as the treatment gas and age for up to 150?days in 20?°C and 65% relative humidity. Scanning electron microscopy shows the fiber surfaces of the ethanol-pretreated?+?APPJ-treated group of freshly prepared, aged for 30?days, and aged for 150?days are covered with polypropylene matrix after fiber pullout tests. X-ray photoelectron spectroscopy shows that the freshly prepared ethanol-pretreated?+?APPJ-treated group has a 31% reduction in atomic ratio of oxygen to carbon and maintains at a similar level even after 150?days of aging. Water contact angle measurement demonstrates that the wettability of fiber surface of the freshly prepared ethanol-pretreated?+?APPJ-treated group drastically decreases and remains at the same lever after aging. Interfacial shear strength test reveals that the interfacial adhesion between PP matrix and ramie fiber for the freshly prepared ethanol-pretreated?+?APPJ-treated group increases 26% and remains substantially higher than that of the control group over time. These results indicate that the ethanol pretreatment followed by APPJ treatment is a permanent surface treatment with negligible aging for at least five months.     

Evaluation of some of the properties of plasma treated wool fabric

Low temperature plasma (LTP) treatment was applied to wool fabric with the use of a nonpolymerizing gas, namely oxygen. Properties of the LTP‐treated samples including low stress mechanical behavior, air permeability, and thermal characteristics were evaluated in this study. Kawabata evaluation system fabric (KES‐F) was employed to determine the tensile, shearing, bending, and compression strength properties and surface roughness of the specimens. The changes in these properties are believed to be closely related to the interfiber and interyarn frictional force induced by the LTP. The decrease in the air permeability of the LTP‐treated wool fabric was found to be probably because of the plasma action effect on increasing the fabric thickness and a change in fabric surface morphology, which was confirmed by scanning electron microscopy micrographs. The change in the thermal properties of the LTP‐treated wool fabric was in good agreement with the earlier findings and can be attributed to the amount of air trapped between the yarns and fibers. This study suggested that the LTP treatment can influence the final properties of the wool fabric, and also provide information for developing LTP‐treated wool fabric for industrial use. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5958–5964, 2006     

Influence of temperature and relative humidity on aging of atmospheric plasma jet treatment effect on ultrahigh-modulus polyethylene fibers

The aging effects of atmospheric pressure plasma treated fiber surfaces are important for storage and processing of the fibers. One of the high-performance fibers, ultrahigh modulus polyethylene (UHMPE) fiber, was chosen as a model system to investigate the aging process of atmospheric pressure plasma jet (APPJ) treated fibers surfaces 0, 7, 15 and 30 days after initial plasma treatment. The fiber was first plasma-treated and then stored at temperatures varying from ?80 to 80°C on the same relative humidity (RH, 0%) and on RH of 0%, 65% and 100% at the same temperature of 20°C. Immediately after the plasma treatment, scanning electron microscope (SEM) showed the roughened fiber surface. X-ray photoelectron spectroscopy analysis showed changed surface chemical compositions. Contact-angle measurement showed increased surface wettability and microbond test showed an increase in IFSS. With increasing relative humidity or decreasing temperature, the IFSS value decreased and the contact angle increased more slowly. However, after 30 days, the IFSS values and contact angles reached a similar level for all groups. Moisture showed no effect on the single fiber tensile strengths during aging. The reasons for the observed aging behavior could be that decreasing temperature or increasing relative humidity hindered the surface rearrangement of polymer chains after plasma treatment.     

Influence of water addition on the modification of polyethylene surface by nitrogen atmospheric pressure plasma jet

Polyethylene (PE) has many excellent material properties (low density, high flexibility, good chemical resistance, etc.), and is widely used in industrial and medical fields. However, the practical applications of PE are sometimes limited due to its poor wettability. In this article, we employ pure nitrogen atmospheric pressure plasma jet (APPJ) and N₂-H₂O APPJ to hydrophilize PE surfaces. Wettability, time stability, chemical composition, micromorphology, and mechanical properties of the treated surfaces are investigated by contact angle measurement, X-ray photoelectron spectroscopy, atomic force microscopy, scanning electron microscopy, and electric digital display push–pull machine. The pure nitrogen APPJ can hydrophilize PE surfaces without inducing obvious microstructure changes, and relatively better wettability (water contact angle = 13°) could thereby be achieved. On the other hand, the N₂-H₂O APPJ creates micro/nanoscale pores on the treated hydrophilic surfaces, contributing to the better time stability and lower tensile strength. The results reported here clearly demonstrate the great potential of nitrogen APPJs with different water mixing ratios in controlling surface wettability and microstructures of polymer surfaces. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47136.     

Effect of plasma treatment on surface structure and properties of polyester fabric

Poly(ethylene terephthalate) fabric was treated by plasma initiated in various gases: nitrogen, oxygen, air, carbon dioxide and ammonia. Plasma-treated fabric showed a considerable change in surface structure and wettability. It was observed that the change in the surface structure of the polyester fibres was closely dependent on the gas type and treatment conditions. The wetting time of plasma treated fabric considerably drops in comparison to untreated fabric and the best results were obtained by treatment in nitrogen, oxygen and air plasma. A good correlation exists between change in the surface structure of the fabric and its wettability. Infra-red a.t.r. spectroscopy showed some differences in the spectra of plasma treated fabrics but these changes are only moderately dependent on the gas type and plasma conditions. Modification of the surface structure of the polyester fibres depends on the current frequency within the studied range of 0.05–100 kHz.     

Effect of plasma pretreatment on enhancing wrinkle resistant property of cotton fiber treated with BTCA and TiO2 System

1,2,3,4‐butanetetracarboxylic acid (BTCA) with titanium dioxide as a catalyst, was used to crosslink cotton fibers for the purpose of enhancing wrinkle recovery angle (WRA). To enhance the BTCA treatment with TiO₂, surface modification of cotton fiber is required; atmospheric pressure plasma jet pretreatment was used in experiments reported in this article. In this study, optimum conditions for plasma pretreatment were analyzed using orthogonal array testing strategy (OATS) technique, on the basis of WRAs achieved after BTCA treatment with and without TiO₂ as catalyst. It was found that (i) longer duration of plasma pretreatment provides enough time for the substrate to be impacted by the concentrated active species produced in plasma gas and therefore, modifies the material surface effectively and offers the best balance between enhancement of WRA and minimization of fiber damage, (ii) high oxygen flow rate producing a severe etching effect that alters the material's surface characteristics. However, when concentration of O₂ increased during the plasma pretreatment, the active species might react with the oxygen also, besides the cotton surface, and (iii) when the distance between the plasma jet nozzle and the substrate surface is too large, plasma gas from the nozzle is unable to hit the fabric surface, which means no surface modification is achieved. As a result, plasma treatment with 2 mm/s treatment speed, 0.1 L/min oxygen flow rate, and 2 mm jet‐to‐substrate distance was the most effective plasma pretreatment. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Transglutaminase‐mediated crosslinking of gelatin onto wool surfaces to improve the fabric properties

In this study, transglutaminase (TGase)‐mediated crosslinking of gelatin on the surface of wool and its effect on the properties of wool fabric were investigated. For the wool fabric used in this study, gelatin (3 g/L) treatment for 1 h combined with 20 U/g of fabric microbial TGase reduced the area shrinkage of KMnO₄‐pretreated wool fabric from 6.53 ± 0.06 to 1.92 ± 0.15%, which was more effective than that treated with gelatin alone (in which the area shrinkage was reduced to 4.02 ± 0.10%). At the same time, the tensile strength recovered from 267 ± 2.0 to 335 ± 2.1 N. The antifelting ability of treated wool fabric exhibited better washing durability. Scanning electron micrographs showed that the gelatin material smoothed the wool fiber surface by coating or filling the raised scales of the wool with TGase. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

常压等离子体处理芳砜纶的结构与性能研究

分别采用氦气和氦气/氧气对芳砜纶进行常压等离子体处理。采用滴水吸收实验测定处理前后纤维表面的润湿性,利用扫描电子显微镜和X射线光电子能谱仪分析处理前后纤维表面形态和化学成分的变化。结果表明:经常压等离子体处理后芳砜纶表面粗糙度增加,纤维表面碳元素含量下降,羟基、羧基等含氧或氮的极性基团增加,芳砜纶纱线的润湿性能提高,纱线强度没有明显变化,氦气/氧气等离子体处理比氦气等离子体处理效果更好。