Surface modification of aromatic polyamide film by remote oxygen plasma

Surface modification of poly(p-phenylene terephthalamide) (PPTA) film by a remote oxygen plasma treatment has been investigated from a viewpoint of comparison with a direct oxygen plasma treatment. We call the modification procedure in a space far away from the oxygen plasma zone “the remote oxygen plasma treatment,” and the modification procedure in a space just in the oxygen plasma zone (a conventional oxygen plasma treatment) “the direct oxygen plasma treatment.” In a space far away from the plasma zone, oxygen radicals rather than electrons and oxygen ions are predominant, and the PPTA film can be modified by the remote oxygen plasma treatment into a hydrophilic surface without heavy degradation of the PPTA film. The PPTA film surfaces modified by the remote oxygen plasma treatment were analyzed with contact angle measurement, scanning microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 831–840, 1997     

Surface modification of a polyurethane film by low pressure glow discharge oxygen plasma treatment

Low pressure oxygen plasma has been used to improve the surface wettability of a polyurethane film. The modifications induced by the plasma treatment in the material were analyzed using contact angle measurements. X‐ray photoelectron spectroscopy technique was used for surface characterization of the plasma‐treated films. Atomic force microscopy and scanning electron microscopy were used to analyze topography changes due to the plasma‐etching mechanism. The results show a much better surface wettability of the film even for short exposure times, with a considerable increase in the surface energy values. As expected, functionalization with oxygen plasma is mainly because of surface oxidation with species like (C? O, C?O, OH, etc). An aging process with regard to polar groups rearrangement has been observed, thus promoting a partial hydrophobic recovery. Besides functionalization, the surface wettability of the material improves as a consequence of a slight increase in surface roughness because of the etching effect of oxygen plasma. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

真空氧等离子体表面改性涤纶织物研究

采用真空氧等离子体对涤纶织物进行表面改性,探讨不同处理压强、处理时间下织物润湿性能和分散染料染色性能的变化。使用X射线光电子能谱技术研究了织物表面处理前后化学组成及元素含量的变化,利用扫描电子显微镜表征了处理后织物表面形貌的变化。结果表明:真空氧等离子体处理后的涤纶织物表面氧元素的含量从24.1%上升到40.7%,表面粗糙程度提高;同时织物的润湿性能提高,润湿时间由1680s下降到51s;等离子体处理后涤纶织物的分散染料染色性能改善,其表面深度值由12.3增加为15.6,透湿量由2941g/(m~2·d)增加为3282g/(m~2·d)。     

氧气低温等离子体对PBO纤维的表面改性

采用氧气低温等离子体对聚对苯撑苯并双噁唑(PBO)纤维进行表面改性,讨论了处理时间、处理功率及气压对PBO纤维单丝强度、与环氧树脂基体的界面剪切强度(π_(IFSS))、形态结构、表面元素组成和亲水性的影响。结果表明:在处理时间为2.5 min,处理功率为30 W,处理气压为50 Pa的最佳工艺条件下,经氧气等离子处理后的PBO纤维与环氧树脂的π_(IFSS)比原丝提高60%,达9.38 MPa,与水的接触角也从105°下降到72°。     

Surface modification of Kevlar 149 fibers by gas plasma treatment

Kevlar 149 fibers have been surface treated with NH₃-, 0₂-, or H₂O-plasm to modify the fiber surfaces. SEM (scanning electron microscopy) is used to characterize the surface topography of fibers etched by gas plasmas. The chemical compositions and functional groups of the fiber surfaces are identified by ESCA (electron spectroscopy for chemical analysis) and SSIMS (static secondary ion mass spectroscopy), respectively. The contact angle of water on modified PPTA [poly(p-phenylene terepbthalamide)] film prepared from using Kevlar 149 fibers is also used to investigate the wettability. The results show that the etching abilities of gas plasmas are dependent on the type of gas used for plasma treatments. The contact angle data indicate that all the three gas plasma treatments are effective in rendering the surface of PPTA more hydrophilic. The ESCA analysis results show that the surface compositions of plasma-treated fibers are highly dependent on the type of gas used and treatment time. Changes in surface compositions of fibers treated by NH₃-, O₂-, and H₂O-plasma are observed. Increasing nitrogen and oxygen contents are observed for the NH₃-plasma treatment, and the O₂- and H₂O-plasma treatments, respectively. Furthermore, the incorporation of amino groups into fiber surfaces by NH₃-plasma treatment and the extensive damage of the aromatic ring and the polymer backbone by H₂O-plasma and O₂-piasma are evidenced by SSIMS.     

Surface modification of poly(tetrafluoroethylene) with pulsed hydrogen plasma

Surface modification of polymers by pulsed plasma has been investigated to minimize degradation reactions occurring at the same time as the surface modification reactions. The hydrogen radical, ion, and electron concentrations in the hydrogen plasma were simulated as a function of the elapsed time after turning off the discharge. The contact angle measurement showed that hydrogen plasma treatment, regardless of pulsed or continuous plasma, led to degradation reactions as well as defluorination and oxidation on PTFE surfaces. The degradation reactions of PTFE chains initiated by the pulsed hydrogen plasma were not as vigorous as those by the continuous hydrogen plasma. A combination of the on‐time/off‐time of 30/270μs in the pulsed hydrogen plasma was efficacious in modifying PTFE surfaces. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 340–348, 2002     

聚酯纤维的低温等离子体表面改性

探讨了聚酯纤维氩气低温等离子体处理的工作条件及处理后纤维的性能和表面形态。结果表明 ,在本实验条件下 ,聚酯纤维经氩气低温等离子体处理后 ,表面形成刻蚀 ,吸湿性明显提高 ,其力学性能和热性能变化不大     

Surface modification of nanofibrillated cellulose films by atmospheric pressure dielectric barrier discharge

A dielectric barrier discharge in a gas mixture of tetrafluoromethane (CF₄) and O₂ was used for tailoring the surface properties of nanofibrillated cellulose (NFC) films. The surface chemical composition of plasma-modified NFC was characterized by means of X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry, while surface morphology was illustrated by atomic force microscopy. Wettability was characterized through the static sessile drop method. The adhesion between NFC and polylactide (PLA) laminated films was tested by the double cantilever beam technique. As a result of atmospheric pressure plasma treatment, the water contact angle of NFC films increased and the values were comparable with those of PLA films. On the other hand, surface chemical characterization revealed inhomogeneity of the plasma treatment and limited improvement in adhesion between NFC and PLA films. Further research in this direction is required in order to enhance the uniformity of the plasma treatment results.     

Surface modification and degradation of poly(lactic acid) films by Ar-plasma

Surface modification of poly(lactic acid) (PLA) film surface by Ar-plasma was investigated by contact angle measurements and XPS in order to answer the following two questions. (1) Could the Ar-plasma modify the PLA film surfaces? (2) What chemical reactions occurred on the film surfaces during the Ar-plasma treatment? The Ar-plasma treatment did not lead to hydrophilic modification of the PLA film surface, but to degradation reactions of the PLA film. Poor modification may be due to instability of the carbon radicals formed from C—O bond scission in the PLA chains by the Ar-plasma.     

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。     

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。     

Surface modification of graphite encapsulated iron nanoparticles by plasma processing

The graphite encapsulated iron nanoparticles were fabricated by using arc discharge method. The synthesized nanoparticles were pre-treated by an inductively-coupled RF Ar plasma and then post-treated by NH₃ plasma under various gas pressures and treatment times. Analyses of XPS spectra have been carried out to study the effect of the plasma treatment on the surface modification of nitrogen-containing groups. The morphological changes of the particles surface by plasma treatment have also been analyzed by using HR-TEM. Present results show that the highest values of N/C atomic ratio of 5.4 % is obtained by applying 10 min of Ar plasma pre-treatment and 2 min of NH₃ plasma post-treatment conducted in RF power of 80 W and gas pressure of 50 Pa.     

低温氧等离子体引发ES纤维接枝丙烯酸的研究

利用低温氧等离子体对ES纤维进行预处理,经与空气接触后接枝丙烯酸。探讨了等离子体处理时间、放电功率、气体压强及接枝单体浓度、接枝反应时间、温度等各因素对接枝率的影响规律。     

Surface modification of polyester and polyamide fabrics by low frequency plasma polymerization of acrylic acid

In this study, the surface characteristics of polyester and polyamide fabrics were changed by plasma polymerization technique utilizing acrylic acid as precursor. This monomer was used to produce hydrophilic materials with extended absorbency. The hydrophilicity, total wrinkle recovery angle (WRA°) and breaking strength of the fabrics were determined prior and after plasma polymerization treatment. The modification of surfaces was carried out at low pressure (<100 Pa) and low temperature (<50°C) plasma conditions. The effects of exposure time and discharge power parameters were optimized by comparing properties of the fabrics before and after plasma polymerization treatments. It was shown that two sides of polyester fabric samples were treated equally and homogeneously in plasma reactor. For polyester fabrics, the minimum wetting time, 0.5 s, was observed at two plasma processing parameters of 10 W–45 min and 10 W–20 min, where untreated fabric has a wetting time of 6 s. For polyester fabrics, the maximum value was obtained at 60 W–5 min with the wrinkle recovery angle of 306° where the untreated fabric has 290°. The optimum plasma conditions for polyamide fabrics were determined as 30 W–45 min where 2 s wetting time was observed. Wrinkle recovery angle of untreated polyamide fabric was 264°. In this study, after plasma polymerization of acrylic acid, wrinkle recovery angle values were increased by 13%. No significant change was observed in breaking strength of both fabrics after plasma treatment. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2318–2322, 2007     

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     

低温等离子体对多孔材料的表面改性研究进展

多孔材料在化工和高新技术领域应用广泛,对其表面进行改性成为近年研究热点.而低温等离子体技术是近来快速发展的材料表面改性技术,在不影响材料基体性能的前提下改善材料表面的物理化学性质,具有广阔的应用前景.在总结国内外科研成果的基础上,介绍了低温等离子体对多孔材料的表面改性原理,综述了现阶段该技术的研究进展,指出了今后研究发展方向.     

Surface modification of polyester films by RF plasma

Plasma treatment of PET films was carried out under argon, followed by exposure to an oxygen atmosphere. The films underwent considerable changes in surface composition and morphology, as demonstrated by contact angle measurements, FTIR‐ATR, AFM, and XPS. It was found that the surface acquired oxygen containing polar functional groups such as —C=O, —OH, and —OOH, which increased in number as the plasma treatment time increased. During storage, the treated films underwent significant surface reorganization, and both the time and temperature contributed to the increase in the contact angle. As revealed by AFM measurements, these changes were accompanied by an increase in roughness in the form of ridges. The ridges were observed to grow in height with increasing treatment time, although their spacing showed little evolution. A correlation among the observations obtained from various techniques was established, giving a comprehensive picture of the structure and dynamics of plasma‐treated PET surfaces. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1083–1091, 2000     

Surface modification of poly(tetrafluoroethylene) film by plasma graft polymerization of sodium vinylsulfonate

Poly(tetrafluoroethylene) (PTFE) surface was modified by the graft polymerization of sodium vinylsulfonate, and the chemical composition of the graft-polymerized PTFE surface was analyzed by X-ray photoelectron spectroscopy. Peroxides were formed on the PTFE surface by a combination procedure of argon plasma irradiation and air exposure, and the graft polymerization of sodium vinylsulfonate was initiated by the peroxide groups at 65–80°C. The peroxide concentration is 3 × 10⁺¹³ to 5 × 10⁺¹³ numbers/cm². The average degree of polymerization of the graft polymers was 3.4 × 10³. The graft polymer is distributed over the PTFE surface, but part of the PTFE surface remains uncovered. The coverage with the graft polymer is 43%. The PTFE surface graft polymerized with sodium vinylsulfonate was somewhat hydrophilic, but the hydrophilicity was lower than that of the PTFE surface modified by plasma treatment. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 77–84, 1997     

Surface modification of a group of polymers using a low temperature cascade arc torch

Surface modification treatments were performed on six different types of polymers using low temperature cascade arc torch (LTCAT) of Ar with or without adding reactive gas of O₂ or H₂O vapor. The effects of the treatments on the wettability enhancement, surface degradation from oligomer formation, and surface stability from the mobility of surface moieties and hydrophobic recovery were investigated. Surface characterization techniques included the static Sessile droplet method and dynamic Wilhelmy balance method. Experimental results indicated that Ar LTCAT treatments of the polymers with shorter treatment times (2 s in most cases) resulted in stable and hydrophilic surfaces without any surface damage from oligomer formation, with the exception of nylon‐6. The excellent results from Ar LTCAT treatments were attributed to the CASING effect (crosslinking via activated species of inert gas). Addition of O₂ into Ar LTCAT resulted in greater wettability of the treated surfaces, but increased surface damage from oligomer formation. Adding H₂O vapor into Ar LTCAT produced extremely hydrophilic surfaces on the polymers, but pronounced surface damage. The surface oligomer formation was attributed to alkoxy degradation reactions and chain scission from overexposure to high energy species. Comparisons of the treatment outcomes for each type of polymer are discussed with respect to the degree of wettability enhancement, the stability of the treated surfaces, and the susceptibility to degradation. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Surface modification of glass by end-capped fluoroalkyl-functional silanes

Novel oligomeric silanes having end-capped fluoroalkyl groups have been synthesized. The glass surface was modified by oligomeric as well as by monomeric silanes. From contact angle measurements, the surface free energies were determined and the surface was shown to be both highly water- and oil-repellent. Oligomeric-type silanes were more reactive and effective than monomeric-type silanes. A linear correlation was observed between the area ratio of the F 1s peak to the Si 2p peak. The structure of the siloxane layer is discussed in terms of a network interphase model.