低温氧等离子体对PET薄膜的表面改性研究

采用氧气低温等离子体,在工作压力为20 Pa,功率为60 W的条件下对聚对苯二甲酸乙二醇酯(PET)薄膜进行了表面改性,借助接触角、X射线光电子能谱仪、扫描探针显微镜、差示扫描量热仪对薄膜改性前后的性能进行了分析和表征。结果表明,处理后的薄膜表面引入了C—N、N—C=O、C=O等新的极性官能团,接触角显著减小;薄膜表面出现了圆锥状或圆球状的突起,粗糙度增加;薄膜的热性能(主要是结晶度)发生了改变。     

聚苯乙烯的氨气等离子处理及其长效亲水改性应用

为了实现聚苯乙烯材料长效亲水改性,利用氨气等离子体对聚苯乙烯材料表面进行可控亲水改性。通过调整功率、处理时间和氨气气体流量等工艺参数,调节聚苯乙烯材料表面亲水改性程度。利用X射线光电子能谱（XPS）和原子力显微镜（AFM）对材料表面化学成分和表面形貌进行分析。监测等离子处理后材料表面接触角以评估亲水改性效果。结果表明：相比气体流量,氨气等离子处理时间和功率对聚苯乙烯材料表面接触角的影响更明显。在功率为400 W,处理时间为120 s,气体流量为200 mL/min条件下,等离子处理后材料表面接触角约（50±1.9）°。等离子处理后材料表面成功引入N元素和O元素,O和N元素原子数比例分别提高至17.27%和12.98%,O/C和N/C含量比分别增至0.25和0.19。等离子处理前后材料表面形貌无明显变化。接触角监测结果表明亲水改性效果至少可维持360 d。氨气等离子处理可有效实现聚苯乙烯材料表面可控亲水改性,且改性效果具有良好的长期稳定性。     

远程等离子体处理对聚四氟乙烯表面的功能化改性

采用远程氩等离子体对聚四氟乙烯(PTFE)膜进行了表面改性研究,通过接触角测定仪、扫描电子显微镜(SEM)和X射线光电子能谱仪(XPS)等手段,分析研究了改性后材料表面结构、性能的变化。结果表明:PTFE表面经远程氩等离子体处理后,表面微观形态和表面化学成分均发生了变化,且处理效果优于常规氩等离子体。远程氩等离子体可以在一定程度上抑制电子、离子的刻蚀作用,强化自由基反应,使材料表面获得更好的改性效果。经远程氩等离子体短时间(100s)处理后,PTFE表面的F/C比例从1.97降至1.44,O/C比例从0.015增至0.086;表面的水接触角从108°减小到53°;表面自由能从22.4×10-5N·cm-1增加至52.3×10-5N·cm-1。     

聚酰亚胺型黏合剂对PTFE微孔薄膜的黏合性能

研究了具有优异耐热性的聚酰亚胺胶黏剂对聚四氟乙烯微孔薄膜的粘接性能.结果表明,聚酰亚胺胶黏剂对未经表面改性的聚四氟乙烯微孔薄膜没有粘接能力.采用钠萘溶液、N2和O2等离子体处理后,聚四氟乙烯微孔薄膜亲水性增强,聚酰亚胺胶黏剂都可以获得不同程度的粘接能力.但不同的处理方法,同等的亲水性条件下,粘接能力有一定的差异.钠萘溶液改性处理时,只有在接触角小于90°的情况下才可以明显改善薄膜的粘接性能.在亲水性90°～120°范围内,等离子处理的粘接效果要好于钠萘处理的情况.     

等离子体反浮选分离黄铁矿与煤的可行性研究

为了增加黄铁矿与煤的可浮性差异,提出了采用低温空气等离子体改性的思路。采用扫描电镜(SEM)、能谱分析(EDS)、X射线光电子能谱分析(XPS)、接触角、浮选试验研究等离子体处理对黄铁矿和有机质表面性质、可浮性的影响。SEM结果显示,改性后黄铁矿表面形貌变化不大,而有机质表面形貌变化剧烈;EDS和XPS分析表明,黄铁矿表面O含量升高,S含量降低,有机质表面O含量升高,C含量降低,且C—C、C—H键含量减少,C—O、COO—键含量急剧增加;接触角及浮选试验结果表明,处理1~5 min黄铁矿与有机质接触角差值增大了3.5~9.7倍。单独浮选时处理后黄铁矿和有机质浮出率均下降,但有机质降幅更大。等离子体改性显著扩大了黄铁矿与有机质可浮性差异,利用其进行反浮选脱除黄铁矿是可行的。     

基于紫外⁃臭氧辐照的挤塑聚苯乙烯表面改性研究

采用紫外?臭氧（UVO）辐照方式对挤塑聚苯乙烯保温板（XPSF）进行了表面改性，通过X射线光电子能谱仪（XPS）、接触角测量仪（CA）和扫描电子显微镜（SEM）对改性前后XPSF表面化学结构、润湿性能及表面形貌的变化规律进行了表征和测试。结果表明，随着UVO辐照时间的延长，XPSF表面含氧官能团数量逐渐增加，尤其在15 min时，XPSF表面的O/C值（O和C原子含量比值）由0.04增加至0.59；经UVO辐照30 min后，XPSF表面与水的接触角从未经处理的101.7°降至37.1°；UVO辐照前后XPSF表面形貌差异很小；随着放置时间的延长，XPSF表面氧含量逐渐降低，表面形成的含氧官能团消失，疏水性产生一定恢复；放置7 d时XPSF表面仍为氧化状态，接触角表现为亲水性；放置14 d时XPSF表面化学性质和润湿性已恢复至原始状态，但XPSF表面形貌并不会随放置时间的变化而改变。     

氨低温等离子体处理低密度聚乙烯薄膜的XPS分析

采用氨低温等离子体对低密度聚乙烯(LDPE)薄膜表面进行了改性处理,用X射线光电子能谱(XPS)分析了薄膜表面的元素组成、相对含量和表面官能团的类型。结果表明,薄膜经氨等离子体处理后,在薄膜表面新形成了C—N、C—O、O C—NH等键,有效地在薄膜表面引入了含氮和含氧基团。     

Ar等离子体对聚醚砜膜表面改性的研究

利用Ar等离子体对聚醚砜膜表面的改性研究其亲水性以及污染率的变化,分别讨论了等离子体功率,等离子处理时间,等离子的流量等因素对改性结果的影响.实验结果表明,随着等离子体功率,处理时间以及流量的增加,聚醚砜膜的亲水性不断增强然后基本不再变化.当等离子体功率为60 W,流量为20 sccm,处理时间为120 s时,获得较优的改性效果.此时聚醚砜膜的接触角由60°减小到10°,亲水性明显增强.污染率由0.652变为0.152,抗污染性能得以提高.     

聚氨酯脲涂层砂浆的耐氯盐浸渍性能研究

研究了采用3.5%氯盐浸渍30～120 d对聚氨酯脲涂层砂浆的氯离子扩散系数、阻抗谱和表面性能的影响;并通过涂层的红外光谱(FT-IR),结合表面接触角变化,探讨了耐氯盐浸渍性能的机理。研究结果表明:氯离子扩散系数随浸渍时间变化规律符合Fick第二定律,120 d后,聚氨酯脲涂层砂浆氯离子扩散系数为0.41×10~(-12)m~2/s,明显低于无涂层砂浆;聚氨酯脲涂层砂浆试件Nyquist图显示,随氯盐浸渍时间增加,低频部分的曲线半径缩小并且向高频区收缩,低频阻抗模值|Z|_(0.01 Hz)呈下降趋势,初始值24 045.02Ω,120 d后降至6 381.39Ω;砂浆电阻值随浸渍时间不均匀降低,电容增加;涂层接触角随氯盐浸渍时间增加而减小,120 d后降低了9.78%,表面能升高,涂层亲水能力提高,总体变化幅度不大,浸泡后依然具有较好的耐氯离子渗透性能。FT-IR谱图揭示出导致上述变化的原因是由于浸泡过程中,涂层表面的N—H、C=O、C—H等基团有轻微断键现象,对涂层防护性能有轻微影响,故涂层表面性能有所下降,但变化幅度较小。     

丙烯酸等离子体聚合对LDPE薄膜的表面改性

为了改变低密度聚乙烯(LDPE)薄膜表面固有的惰性及疏水性,赋予其表面"永久"的亲水性能。以丙烯酸为单体,采用射频辉光放电等离子体聚合的方法对其进行了表面修饰,并用XPS、FTIR-ATR和SEM对改性前后薄膜的表面性能进行了分析。结果表明:聚合处理后薄膜表面O元素的含量明显增加,形成了C—O、C=O、COOH等含氧极性官能团,薄膜表面出现了大小不同的颗粒状丙烯酸聚合物。     

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 properties of polymers treated with tetrafluoromethane plasma

Polymer films of poly(ethylene terephthalate), polypropylene, and cellophane were surface treated with tetrafluoromethane plasma under different time, power, and pressure conditions. Contact angles for water and methylene iodide and surface energy were analyzed with a dynamic contact angle analyzer. The stability of the treated surfaces was investigated by washing them with water or acetone, followed by contact angle measurements. The plasma treatments decreased the surface energies to 2–20 mJ/m² and consequently enhanced the hydrophobicity and oleophobicity of the materials. The treated surfaces were only moderately affected after washing with water and acetone, indicating stable surface treatments. The chemical composition of the material surfaces was analyzed with X-ray photoelectron spectroscopy (XPS) and revealed the incorporation of about 35–60 atomic % fluorine atoms in the surfaces after the treatments. The relative chemical composition of the C ls spectra's showed the incorporation of —CHF— groups and highly nonpolar —CF₂— and —CF₃ groups in the surfaces and also —CH₂—CF₂— groups in the surface of polypropylene. The hydrophobicity and oleophobicity improved with increased content of nonpolar —CF₂—, —CF₃, and —CH₂—CF₂— groups in the surfaces. For polyester and polypropylene, all major changes in chemical composition, advancing contact angle, and surface energy are attained after plasma treatment for one minute, while longer treatment time is required for cellophane. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1591–1601, 1997     

Plasma‐induced surface modification and adhesion enhancement of polypropylene surface

Unoriented (UPP) and biaxially oriented (BOPP) polypropylene films were treated under radio frequency plasma of air, nitrogen, oxygen, and ammonia. Surface modification of polypropylene films was investigated by using surface energy measurement and attenuated total reflection (ATR)‐FTIR spectroscopy. Surface energy of air and nitrogen plasma‐treated polypropylene film increased for shorter treatment time and then decreased and attained an equilibrium value. Such changes in surface energy were not observed for oxygen and ammonia plasma‐treated polypropylene film, which increased to an equilibrium value. ATR‐FTIR studies revealed characteristic differences in the absorption spectra for short‐duration and long‐duration treatments. From the relative intensity change in the C—H stretching vibration, the mechanism of surface chemical reaction could be inferred. Studies regarding the durability of surface modification due to plasma treatment were evaluated by investigating surface energy of samples aged for 2 months. Treated films subjected to peel strength measurement showed improvement in bondability for UPP and BOPP film by hydrophilic surface modification accompanied by surface crosslinking. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 925–936, 2002     

Novel surface modification of high‐density polyethylene films by using enzymatic catalysis

The surface of high‐density polyethylene (HDPE) films was modified by an enzyme, soybean peroxidase (SBP). The enzymatic surface modification was performed using a peroxidase as catalyst and hydrogen peroxide as oxidizing agent. The chemical composition and morphology of HDPE surfaces were characterized by X‐ray photoelectron spectroscopy, infrared spectroscopy, and scanning electron microscopy. Results showed that after enzymatic treatment, the O/C atomic ratio of HDPE surfaces increased, and new functional groups such as –CO– appeared. Moreover, the surface of treated HDPE films became rougher than untreated surfaces. The hydrophilicity of treated and untreated HDPE films was analyzed by UV–vis spectroscopy and contact angle measurements. The decreased contact angle of the HDPE with water and increased adsorption ability of the surface to a water‐soluble dye clearly indicated that enzymatic treatment can significantly increase the hydrophilicity of the surfaces of HDPE films. The catalytic mechanism of SBP was also discussed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3673–3678, 2004     

Adhesion aspects of poly(p-xylylene) to SiO2 surfaces using γ-methacryloxypropyltrimethoxysilane as an adhesion promoter

The use of organo-silanes as coupling agents offers the potential to create novel structures using materials that would otherwise suffer from poor adhesion. γ-methacryloxypropyltrimethoxysilane (γ-MAPTS) layers were deposited on hydroxylated SiO₂ surfaces using both vapor and solution deposition techniques. The films were characterized using variable angle spectroscopic ellipsometry, infrared spectroscopy, contact-angle measurements and X-ray photoelectron spectroscopy. Film thickness was relatively constant at ～6 Å for solution deposition times from 2 min to 2 h at 60° C. Water contact angle increased from 0° to 45° after silane deposition from solution. Room temperature vapor-deposited γ-MAPTS films showed similar thicknesses to those of solution deposited films but a markedly lower contact angle of 10°. Parylene N was chemical vapor deposited on the γ-MAPTS films and its adhesion was tested using the Scotch^® Tape test. The γ-MAPTS improved adhesion of parylene N to the hydroxylated surface, with the adhesion for the vapor deposited silane films exhibiting a temperature and time dependence.     

贮存环境对PE-WPC等离子体处理时效性的影响(I)——表面结构及粘接性能

利用等离子体处理技术对聚乙烯木塑复合材料(PE-WPC)进行表面处理以改善其胶接性能,将处理后的WPC分别贮存在真空(室温)、空气(室温)和空气(低温)环境中,利用接触角、FT-IR和胶接强度测试等手段,研究了不同贮存环境对等离子体处理后材料表面时效性的影响。接触角测试结果表明,随着放置时间的延长,贮存在3种环境中的试样的表面接触角均逐渐增大,相比之下,处于真空和低温环境中的试样接触角变化较小;红外光谱分析表明,贮存于3种环境中的试样表面的-OH基团随着放置时间的延长几乎消失,-C-O和C=O基团也逐渐减少,处于真空和低温环境中的试样表面残留的极性基团较空气中的试样多。胶接强度测试结果表明,随着放置时间的延长,放置在3种环境中的试样表面粘接强度逐渐降低,其中放置于空气(室温)中的试样的粘接强度降低的幅度最大。等离子体处理尽管存在时效性,但贮存30d的试样的胶接性能仍优于未处理的试样。     

Improvement of the water selectivity of ULTEM poly(ether imide) pervaporation films by an allylamine‐plasma‐polymerized layer

The wettability and surface energy of extruded ULTEM poly(ether imide) films strongly increased (the water contact angle varied from 75 to 38° and the surface energy varied from 45.3 to 59.5 mJ m^?2, respectively) with the deposition of an allylamine‐plasma‐polymerized layer and were characterized with X‐ray photoelectron spectroscopy, scanning electron microscopy, and atomic force microscopy according to the experimental parameters. Pervaporation tests for dehydrating the water/ethanol azeotropic mixture were performed at 40°C with nontreated and plasma‐treated ULTEM films for 15, 30, 60, and 120 min. No significant difference was noticed in the total flow (ca. 2.5 g/m² h) among the various films. However, for the 30‐min duration, a great increase in the water selectivity from 850 to 10,850 was measured, and it was related to the higher N/C ratio and the presence of amide groups on the surface. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2088–2096, 2005     

Characterization of surface‐modified polyalkanoate films for biomedical applications

Poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBHV) films prepared by solvent casting were treated with oxygen, argon, and nitrogen radiofrequency‐generated plasmas. The analysis by attenuated total reflectance infrared spectroscopy and X‐ray absorption near edge spectroscopy of modified surfaces showed an increase of hydroxyl and unsaturated groups, compared with unmodified surfaces. Water contact angles decreased after a short time of exposure (<30 s) for all types of plasma. At long exposure times (>30 s), the water contact angles appeared to be independent of treatment time for nitrogen and argon plasmas, whereas they continuously decreased for films treated with oxygen. HaCaT cultures on nontreated and treated PHBHV films showed that short plasma exposures of 10–20 s improve cell attachment to a greater extent than long exposure times habitually used in polymer surface plasma treatment. The film surface topology did not influence cell attachment. These results illustrate the importance of a detailed characterization of the surface physicochemistry in plasma‐modified substrates designed as part of a strategy to optimize specific cell–biomaterial interactions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Surface modification of polypropylene in an impulse corona discharge

The impulse corona discharge was applied to modify surface of polypropylene films. The modified surface was analyzed by contact angle measurements and ESCA. The results were compared to those treated with AC corona discharge. The impulse corona treatment provided a similar contact angle and a similar [O]/[C] ratio on the polymer surface to those in AC corona treatment. On the other hand, [N]/[C] in impulse discharge was much lower than that in AC pulse discharge. The total power input in the impulse corona discharge, however, was lower than that in AC corona discharge to achieve a similar level of surface modification. It was also observed that the lower repetition frequency, the lower contact angle, and the higher [O]/[C].