纤维增强环氧复合材料的激光和等离子体涂装前处理技术

为了提高涂料在玻纤增强复合材料表面的附着力,以激光和等离子体表面改性技术对纤维增强环氧复合材料进行了涂装前处理,采用三维体式显微镜、接触角测试仪和表面粗糙度仪研究了前处理对复合材料表面形貌、水接触角及表面粗糙度的影响。结果表明:激光处理能明显改变材料表面形貌,增加表面水接触角和表面粗糙度,等离子体处理对材料表面形貌和表面粗糙度的影响较小,接触角与处理次数、处理功率和处理后时间的变化有关。     

氩气低温等离子体处理HDPE薄膜表面的性能研究

利用低温等离子体,以氩气为工作气体,在工作压强为20Pa、处理功率为30W的条件下对HDPE薄膜进行了表面改性。用接触角、SEM、AFM、XPS等手段对改性结果进行了分析和表征。研究结果表明:在0～300s的处理时间内,失重率在处理时间为90s左右时达最大值;接触角在0～160s内随处理时间的增加显著减小,而在160～300s的处理时间内没有发生明显变化;改性后的接触角随着放置时间的推移出现微弱回复;HDPE薄膜经过氩气低温等离子体处理后,能在其表面形成各种极性基团,主要是羰基、羟基和羧基,且薄膜经处理后,其表面的结合能及平面光洁度发生了改变。     

低温O_2等离子体对HDPE薄膜的表面改性

利用氧气低温等离子体,在工作压力为20Pa、功率为30W的条件下对HDPE薄膜进行表面改性。采用接触角、FT-IR-ATR、AFM、DSC等现代分析手段对改性结果进行了分析和表征。结果表明,单位面积的失重率随处理时间的延长逐渐增大;接触角随处理时间的延长呈逐渐减小的趋势;处理HDPE薄膜能在其表面形成各种极性基团,主要是羰基和羧基;处理后薄膜的热性能(熔点和结晶度)发生一定改变。     

等离子体引发接枝聚合改善聚丙烯表面的亲水性

将等离子体引发接枝技术用于聚丙烯（PP）膜表面接枝丙烯酸。FT—IR证明处理后的膜表面存在有羧基,染色法定量测定了羧基的含量。另外,对修饰后的聚丙烯膜表面进行接触角的测定。结果表明,等离子体引发接枝聚合可明显改善聚丙烯膜表面亲水性,能控制PP膜表面的接枝率大小,可得到不同水接触角的PP膜,进而能人为调节PP膜的表面亲水性。     

HDPE薄膜低温等离子体改性与粘接性能研究

利用氧气低温等离子体,在真空度为20 Pa,处理功率为30 W的条件下,对高密度聚乙烯(HDPE)薄膜进行了表面改性。研究结果表明:在20~200 s的处理时间内,单位面积的失重率随处理时间的增加线性增大,表面粗糙度也随着增加;处理后薄膜表面的接触角显著减小;接触角越小,剥离强度就越大;处理后能在薄膜表面形成羟基、羰基和羧基等各种极性基团。     

低温空气等离子体改性PDMS的研究

为了改善聚二甲基硅氧烷（PDMS）的亲水性和稳定其电渗性能,采用空气微波等离子体在低温条件下对其表面进行改性。利用原子力显微镜（AFM）、X射线光电子能谱（XPS）及静态接触角对处理前后的PDMS进行分析。经空气微波等离子体处理3min后,PDMS的亲水性得到极大的改善,水在其表面的接触角接近零度。XPS结果表明：处理后PDMS表面形成SiOx薄层;AFM显示空气等离子体处理对PDMS的表面没有损伤。与文献报道的高、中真空氧等离子体处理方法相比,亲水效果基本一致,却大幅度降低了对设备真空系统的要求,并缩短了操作时间,节约了成本。最佳处理条件为：微波为100W,腔体内气压为1.0kPa,空气的流量为20sccm（1sccm=1cm3·min^-1）,时间3min。     

大气压等离子体射流改性船体钢表面亲水性研究

在室温下,采用大气压等离子体射流对船体钢进行表面改性,通过水接触角测量、扫描电镜、X射线光电子能谱等分析测试方法研究了等离子体射流处理前后船体钢表面润湿性、表面形貌及化学特性的变化。研究结果表明,船体钢经大气压空气等离子体射流处理后在其表面引入了大量含氧基团,处理2s表面的水接触角就可以降到30°以下;处理后材料表面的亲水性受处理时间及放电电流的影响且在空气中放置时会出现老化效应,处理时间越长,老化效应越弱。     

均匀介质阻挡放电处理提高聚合物薄膜表面亲水性的研究

用中等气压空气中均匀介质阻挡放电(DBD)产生的低温等离子体对聚甲基丙烯酸甲酯(PMMA)和聚碳酸酯(PC)两种聚合物薄膜进行表面改性,研究了DBD等离子体处理对两种材料表面亲水性的影响。通过接触角测量和表面能测量以及全反射傅里叶变换红外光谱等手段研究了等离子体处理前后PMMA和PC的表面特性。测量了不同功率密度下材料表面水接触角和表面能随处理时间的变化规律以及处理后的材料在空气中放置时的退化效应,并对改性的机理进行分析。结果表明,两种聚合物薄膜经DBD等离子体处理后,接触角随处理时间的增加而降低,表面能随处理时间的增加而增加,两者均在一定处理时间达到饱和值;增大均匀DBD处理的功率密度,利用更少的处理时间就能得到同样的处理效果。处理后的材料在空气中放置时会出现退化效应,但即使放置14d后材料表面水接触角仍远低于处理前的值。     

利用直流辉光放电等离子体改善聚氯乙烯细管内表面亲水性的研究

采用低气压氩气直流辉光放电等离子体对PVC细管内表面进行了处理,使其内表面亲水性得到显著改善,且处理效果均匀.处理时间越长PVC细管内表而的水接触角越小.经过处理后的PVC细管放置室内大气环境后内表面的水接触角出现退化,72小时以后基本稳定,稳定后的内表面水接触角显著好于未经处理的PVC细管.     

MAH等离子体改性PVDF薄膜表面的亲水性研究

以马来酸酐(MAH)低温等离子体接枝聚合的方法对聚偏氟乙烯(PVDF)薄膜表面进行亲水改性.分析了袁面的MAH化学结构;考察了等离子体功率与表面聚合量和表面水接触角的关系;讨论了改性薄膜在热浓硫酸中长期作用的结果.结果表明:等离子体使MAH在表面双键打开并接枝聚合;聚合量随处理功率的增加呈先上升后下降的趋势,30W时最大;经过等离子体处理后,水接触角由97°下降至45°～70°,水解后降低至40°～55°,30W的改性膜表面水接触角最小;改性薄膜在热浓硫酸中作用1000h后,MAH聚合物没有被腐蚀掉,与未浸泡硫酸试样相比,水接触角变化不大.     

氧气等离子体处理对CFRP表面特性及胶接界面力学性能的影响EI北大核心CSCD

为改善碳纤维增强复合材料(CFRP)胶接界面力学性能,采用低温氧气等离子体处理设备对CFRP进行表面处理。利用接触角测量仪、扫描电子显微镜(SEM)、原子力显微镜(AFM)、X射线光电子能谱(XPS)对CFRP表面润湿性、表面能、表面形貌、表面化学组分等进行表征,通过双悬臂梁实验(DCB)对CFRP胶接界面力学性能进行研究。结果表明:随氧气等离子体处理时间从0 s增加至30 s,表面水接触角从97°降至29°,CFRP表面润湿性达到最佳,极性分量占比显著增多;随处理时间的增加,CFRP表面粗糙度和最大高低差降低,形成较多谷峰分布的纳米级沟壑,基体表面积增大;同时,表面C—O和C■O等含氧极性官能团含量明显增加,C—C/C—H和Si—C官能团含量减少,表面污染物得到有效清除和转化;与未处理相比,经氧气等离子体处理20 s后,CFRP胶接界面最大剥离载荷和Ⅰ型断裂韧度分别提高了1.01倍(62.73 N)和1.92倍(649.21 J/m 2)。研究发现,氧气等离子体处理可以显著改善CFRP表面物理化学特性,有利于CFRP与胶黏剂更好的黏结,提高胶接界面剥离强度与韧性。     

Characterisation of FR-4 substrate with various plasma treatment conditions

Abstract

The effects of plasma treatment on the surface of the flame resistant-4 (FR-4) substrate with underfills under various treatment conditions (operating gas, operating time, operating power) are investigated by using contact angle measurement, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The plasma treatment on substrate surfaces increased the oxygen containing functional groups or the polar component of the surface free energy, improving the wetting characteristics of the underfills/FR-4 substrates. The plasma treatment conditions which minimised the contact angle between the underfills and FR-4 substrates were an operating power of 300 W and operating time of 180 s under Ar gas atmosphere.     

Plasma modification of polyolefin surfaces

In order to functionalize the surface of blown low‐density polyethylene (LDPE) and cast polypropylene (CPP) films, and ultimately to maximize the attachment of active molecules onto them, the optimum treatment parameters of capacitively‐coupled radio‐frequency (13.56 MHz) oxygen plasma were investigated by using contact angle, toluidine blue dye assay, X‐ray Photoelectron Spectroscopy (XPS) and Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR‐FTIR). Contact angle values of LDPE and CPP samples decreased significantly after oxygen plasma treatment. They further decreased as the plasma power level increased. The treatment time had no substantial effect on contact angle value. The optimum treatment conditions for LDPE and CPP films for maximizing carboxyl functionality without causing observable surface changes were found to be 200 W/200 mTorr and 250 W/50 mTorr, respectively, when treated for 3 min. The maximum carboxyl group concentration obtained with LDPE and CPP films were 0.46 and 0.56 nmol/cm², respectively. The percent of oxygen atoms on the surface of plasma‐treated LDPE and CPP films was determined by XPS analysis to be 22.6 and 28.7%, respectively. The ATR‐FTIR absorption bands at 1725–1700 cm^?1 confirmed the presence of carboxylic acids on LDPE and CPP films. By exposing the plasma‐treated sample to air rather than water and treating films repeatedly with oxygen plasma, a higher carboxyl group concentration could be obtained. Copyright © 2008 John Wiley & Sons, Ltd.     

带有环氧基团含氟共聚物对环氧涂料的改性

采用自由基乳液聚合的方法制备带有环氧基团的聚丙烯酸全氟烷基乙酯-甲基丙烯酸缩水甘油酯-苯乙烯无规共聚物P(FA-co-GMA-co-St),用红外光谱(FT-IR)和核磁共振(1H-NMR)对共聚物进行表征并将其用于环氧涂料的改性。XPS测试结果表明,带有环氧基团的含氟共聚物改性环氧涂层经蒸馏水浸泡48 h后接触角下降了15°为116°,表面氟元素含量下降了5.36%;而不带有环氧基团共聚物改性环氧漆膜经水浸泡48 h以后接触角下降了48°为88°,表面氟元素含量下降了7.94%。GMA单体的引入极大地提高了环氧涂层在湿润环境中的疏水性。     

Surface Modification of Electrospun Polycaprolactone Nanofiber Meshes by Plasma Treatment to Enhance Biological Performance

A critical aspect in the development of biomaterials is the optimization of their surface properties to achieve an adequate cell response. In the present work, electrospun polycaprolactone nanofiber meshes (NFMs) are treated by radio‐frequency (RF) plasma using different gases (Ar or O₂), power (20 or 30 W), and exposure time (5 or 10 min). Morphological and roughness analysis show topographical changes on the plasma‐treated NFMs. X‐ray photoelectron spectroscopy (XPS) results indicate an increment of the oxygen‐containing groups, mainly ? OH and ? C?O, at the plasma‐treated surfaces. Accordingly, the glycerol contact angle results demonstrate a decrease in the hydrophobicity of plasma‐treated meshes, particularly in the O₂‐treated ones. Three model cell lines (fibroblasts, chondrocytes, and osteoblasts) are used to study the effect of plasma treatments over the morphology, cell adhesion, and proliferation. A plasma treatment with O₂ and one with Ar are found to be the most successful for all the studied cell types. The influence of hydrophilicity and roughness of those NFMs on their biological performance is discussed. Despite the often claimed morphological similarity of NFMs to natural extracellular matrixes, their surface properties contribute substantially to the cellular performance and therefore those should be optimized.     

Surface treatment of polycarbonate and polyethersulphone for SiNx thin film deposition

Silicon nitride thin films were deposited with good adhesion on plasma treated polyethersulphone (PES) and polycarbonate (PC) substrates by in-situ rf magnetron sputtering. The surfaces of the PES and PC substrates were performed by plasma treatment at various rf powers and processing time in Ar, O₂ atmosphere. From the X-ray Photoelectron Spectroscopy (XPS) examination of the surface of the treated substrates, it was found that the ratio of oxide containing bonds increased with increasing rf power. The surface roughness of the PES and PC substrates increased with increasing rf power. The plasma treated surface of the substrates became hydrophilic as measured by the water contact angle. The water contact angle for the PES and PC substrates decreased with increasing rf power and processing time, significantly. The lowest value of the contact angle of 14.09° was observed at rf power of 200 W. It was observed that the adhesion properties between the SiN_x films and substrates were enhanced by the plasma treatment.     

Surface property change of C doped TiO2 nano-pillars by O2 plasma treatment

TiO2 surface is led to super-hydrophilic surface by modifying to hydroxyl group. The super-hydrophilic surface can be applied to anti-fogging, because of preventing formation of water droplet on the surface. Super-hydrophilic coatings are made of metal oxides, polymers, or their mixtures. In this study, columnar-structured C doped TiO2 nano-pillars were grown on glass substrates by MOCVD method. For change of surface properties, grown columnar-structured C-TiO2 nano-pillars were treated by oxygen plasma. After oxygen plasma treatment, the surface property of grown columnar structured C-TiO2 nano-pillars changed from hydrophobic surface to super hydrophilic surface. For determination of this mechanism, scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), FT-IR spectroscopy, and contact angle analyzer were employed.     

Hydrophobic and hydrophilic surface nano-modification of PET fabric by plasma process

Polyethylene terephthalate (PET) fabrics were treated by radio frequency inductively coupled plasma (RF-ICP) to modify their hydrophobic and hydrophilic properties. Types of gases which were SF6, O2, N2 and Ar, treatment time, pressure and RF power were varied systematically. The water droplet contact angle measurements showed that, treating with SF6 plasma would result in the increase of hydrophobicity of PET samples while treating with O2, N2 and Ar plasmas would yield hydrophilic properties. In both hydrophobic and hydrophilic cases, the surface morphology of PET fibers was roughened after exposed to plasma. Hence, it is not obvious that these surface roughness induced by plasma is sufficient to yield the increase in hydrophobicity by the well known lotus effect.     

Plasma nano-modification of poly(ethylene terephthalate) fabric for pigment adhesion enhancement

Poly(ethylene terephthalate) (PET) fabrics were modified by treating with radio frequency (RF) plasma of different gases, including argon (Ar), nitrogen (N2), oxygen (O2) and sulfur hexafluoride (SF6), under varied power (50-150 watt) and time period (0.5-20 min). Observations indicated that plasma has affected the morphology and roughness of PET fiber surface in the nano-scale level. After plasma treatment, test patterns were printed by inkjet printer directly onto the sample surface. The enhancement of color printing performance on PET fabric by plasma treatment was evaluated by color spectroscopy. The surface nano-modified PET fabrics by Ar, N2, O2, and SF6 plasmas all exhibited enhanced color yield. AFM, SEM, FTIR-ATR and XPS results suggested that the improved pigment color yield was neither clearly contributed by the wettability of the fabrics nor the polar group induced onto the fiber surfaces but rather mainly by the alteration of surface roughness.