酸碱处理对聚酰亚胺薄膜的表面改性

采用酸碱处理的方法对聚酰亚胺(PI)薄膜表面改性。利用万能试验机和热失重仪考察了处理前后PI薄膜力学性能和热性能的变化情况,并通过傅立叶红外光谱仪、原子力显微镜及视频接触角仪对PI薄膜改性前后表面性能进行了表征。结果表明,经酸碱处理后,PI薄膜表面化学组成和表面形貌均发生变化,表面亲水性增大;当处理时间为4min时,力学性能保持在97%以上,热稳定性略有下降;均方根粗糙度从1.057nm增大到3.002nm,接触角从77.32°下降到46.70°,粘接功提高了38.20%。     

新型涂层Parylene薄膜表面改性研究进展

Parylene薄膜是电子产品包封和器件上不可缺少的组成部分,也是生物传感器上具有很好生物相容性的材料,还是投入应用的防护材料中最优秀的涂层材料之一.简要介绍了Parylene薄膜的优异性能,分析了其存在的主要问题,即表面化学隋性、粘接性能差,表面能有待进一步提高,指出表面改性是改善上述问题的有效途径;综述了国内外对Parylene薄膜表面改性研究的最新进展,并讨论了各改性方法的局限.     

聚酰亚胺薄膜表面导电金属层化学沉积技术研究

为赋予聚酰亚胺(Polyimide, PI)薄膜材料表面良好的导电性,满足其在雷达天线等航空、航天领域的应用,采用化学碱蚀法对表面具有极高化学惰性的PI薄膜进行界面微纳改性处理,并结合化学镀铜沉积技术,实现了PI薄膜表面导电金属层的制备。利用SEM、XRD、AFM、FTIR等对聚酰亚胺薄膜表面改性前后的微观结构和表面金属层性能进行表征。常温化学碱蚀后的PI薄膜表面呈现出树枝状与铆钉状微观结构交错均匀分布的凸起结构形貌,60℃碱蚀后的PI薄膜表面呈现出微小凹坑特征,且碱蚀后PI薄膜表面亲水性明显增强。PI薄膜表面金属镀层均匀致密,导电性良好,且镀层与PI薄膜基材之间具有良好的结合力。碱蚀改性后PI薄膜表面呈现出相互交错的微观凸起亲水性结构,为PI薄膜表面金属层的成核、结晶提供良好的沉积与互嵌结合点,形成PI薄膜表面金属层与基材之间良好的界面互锁,从而有利于提高表面镀层结合强度。本工作实现了化学碱蚀作用下聚酰亚胺薄膜表面高导电、高结合强度金属层的制备,可为聚酰亚胺薄膜在雷达天线等航空、航天领域的应用提供技术支撑。     

聚乙烯薄膜表面放射线改性

聚乙烯薄膜表面放射线改性聚乙烯薄膜价格便宜，用途广泛。但由于没有极性基团不能粘接和印刷。用电晕放电方法进行表面改性，印刷性能有所改善，但仍不尽人意。近年来采用放射线照射进行表面改性，粘接性能明显提高。改性用的聚乙烯薄膜，可用线型低密度薄膜（ＬＬＤ），...     

聚酰亚胺薄膜与太阳翼基板粘贴技术研究

卫星在轨运行过程中,太阳翼会受到恶劣的低真空、温度等环境因素影响,为了提高太阳翼在轨运行过程中的可靠性,对聚酰亚胺薄膜与太阳翼基板的粘贴技术进行了实验研究。结果表明:对聚酰亚胺薄膜表面进行电晕处理,能够显著地提高其表面粗糙度。聚酰亚胺薄膜与硅橡胶结合力得到大大提高,聚酰亚胺薄膜与基板剥离强度达到8.59N/cm,经过热真空及温度循环实验验证,电晕后的聚酰亚胺薄膜薄膜与基板粘贴牢固可靠,能够适应空间恶劣的环境。电晕技术为聚酰亚胺薄膜与基板的粘贴提供了一种有效的表面处理方法,可以推广至航天器其他舱外部件上使用。     

超高分子量聚乙烯纤维表面改性的研究进展

介绍了超高贫子量聚乙烯(UHMWPE)纤维的各种表面改性方法,如低温等离子体改性、辐照接枝改性、化学氧化法改性等,重点讨论了这些方法对纤维复合材料的粘接性能和力学性能的影响,并对主要的纤维表面改性方法所具备的工艺特点、处理效果以及成本等作了对比分析,特别关注了近年来UHMWPE纤维的各种表面改性技术的进展,介绍了改性UHMWPE纤维的性能表征方法,对超高分子量聚乙烯纤维表面改性技术的工业化应用提出建议.     

聚乙烯醇水凝胶与聚乙烯薄膜的表面粘接

用铬酸氧化方法处理聚乙烯(PE)薄膜,得到了表面刻蚀均匀的化学改性薄膜;利用XPS、IR表征了薄膜表面的化学变化,采用SEM、AFM、接触角表征了薄膜表面微观结构和物理性能。制备可化学交联及物理交联成水凝胶的聚乙烯醇(PVA)溶液,与表面刻蚀的PE薄膜复合,得到了PVA水凝胶与PE薄膜的表面复合材料。通过剥离强度测定、SEM观察,表明PVA水凝胶与PE薄膜很好地粘接在一起。     

氟橡胶的表面粘接改性

用紫外线、臭氧、紫外线-臭氧处理6、0Co-γ射线辐射及苯乙烯/丙烯酸接枝方法,对粘接性差的氟橡胶表面进行改性。通过研究氟胶与金属粘接的剪切强度,考察了改性效果。结果表明,用60Co-γ射线进行辐射接枝丙烯酸后粘接性能最好,达到了11.04 MPa,比未改性的提高了50.8%。SEM表明,经表面改性处理后,氟胶表面粗糙程度均增加。电子能谱观察和FT-IR证明了改性后的氟胶表面引入了含N、O的极性基团。     

聚酰亚胺薄膜的等离子体浸没离子注入电性能转变

用等离子体浸没离子注入(PIII)对聚酰亚胺(PI)薄膜进行表面改性处理,研究在不同注入时间条件下聚酰亚胺薄膜表面电性能的转变,并通过X光电子能谱(XPS)分析其转变的机理。结果表明,经等离子体浸没离子注入处理后,聚酰亚胺薄膜的表面电阻与未处理的样品比较下降了约6个数量级,而且没有时效性问题;XPS分析结果表明处理后样品表面的C、N元素含量增加,O元素含量减少,说明样品表面受离子轰击发生了损伤,C=O、C-N键断裂,因此聚酰亚胺薄膜表面电阻下降主要是由薄膜表面发生碳化引起。     

SiO_2表面包覆改性钛酸钡/聚酰亚胺复合薄膜的制备与性能

以聚酰亚胺(PI)为基体,将聚酰亚胺与钛酸钡(BaTiO3)纳米粒子进行复合,采用原位聚合法制备BaTiO3/PI复合薄膜。为提高BaTiO3纳米粒子的分散性和表面性能,采用SiO2对BaTiO3纳米粒子进行表面包覆改性,并制备改性BaTiO3/PI复合薄膜。采用红外光谱、X射线衍射、扫描电镜等对制备得到的改性BaTiO3进行了表征,测试了复合薄膜的介电性能。结果发现,SiO2与BaTiO3粒子间仅是物理包覆,没有新物质形成。测试频率为103 Hz时,质量分数为5%的SiO2包覆改性使复合薄膜的介电常数增大到21.8,介电损耗为0.00521,击穿强度为76 MV/m,储能密度为0.56J/cm3。研究表明,采用SiO2对BaTiO3改性使得复合薄膜的介电性能有所提高。     

Fabrication and mechanism study of CuO layers on double surfaces of polyimide substrate using surface modification

Formation process and mechanism of continuous CuO layers on double surfaces of polyimide films were studied. The composite films were prepared using the facile surface modification and ion exchange technique. By alkaline-induced chemical modification and ion-exchange reaction, Cu²⁺ ions were incorporated into the surface of polyimide substrate. Thermal treatment in ambient atmosphere resulted in the formation of CuO particles that further agglomerated on the film surface and produced well-defined CuO thin layers on the double surfaces of polyimide films. The changes in the chemical structure, surface morphology, crystalline state and the surface roughness with the increase of ambient temperature were investigated. It was interesting to find that the conversion of metallic copper and low valence sub-oxide Cu₂O to high valence oxide CuO was observed in the thermal treatment process. The agglomeration mechanism for the CuO particles was proposed and proved by three steps, which illustrated that copper-catalyzed and oxygen-assisted decomposition of the polyimide overlayer resulted in the agglomeration of CuO particles. The final composite films retained the thermal stability of the pure polyimide.     

等离子体轰击致聚酰亚胺表面亲水性研究

等离子体轰击聚酰亚胺表面会提高挠性印制电路板中溅射铜膜与聚酰亚胺基板的附着力,同时聚酰亚胺表面亲水性随之改变.本文通过改变轰击等离子体种类、轰击电流、轰击时间和轰击气压等条件,研究这些工艺参数与聚酰亚胺表面亲水性的相互关系.在等离子体轰击处理后的聚酰亚胺上磁控溅射镀铜并电镀加厚,利用剥离强度测试仪测量铜膜与聚酰亚胺基板的附着力,并分析亲水性与附着力之间的关系.研究发现,等离子体轰击可以增强聚酰亚胺的亲水性及聚酰亚胺基板与铜膜的附着力,且亲水性越好的样品,溅射镀铜后铜膜与基板的附着力也越好,并得到了等离子体轰击参数与亲水性的关系;研究表明可以把测量亲水性作为聚酰亚胺表面等离子体轰击效果的一种评价方法.     

Effects of porous carbon additives and induced fluorine on low dielectric constant polyimide synthesized with an e-beam

We report the synthesis of a polyimide matrix with a low dielectric constant for application as an intercalation material between metal interconnections in electronic devices. Porous activated carbon was embedded in the polyimide to reduce the dielectric constant, and a thin film of the complex was obtained using the spin-coating and e-beam irradiation methods. The surface of the thin film was modified with fluorine functional groups to impart water resistance and reduce the dielectric constant further. The water resistance was significantly improved by the modification with hydrophobic fluorine groups. The dielectric constant was effectively decreased by porous activated carbon. The fluorine modification also resulted in a low dielectric constant on the polyimide surface by reducing the polar surface free energy. The dielectric constant of polyimide film decreased from 2.98 to 1.9 by effects of porous activated carbon additive and fluorine surface modification.     

Poly(dimethylsiloxane)-polyimide blends in the formation of thick polyimide films

Thick polyimide layers can be formed by using some unique properties of poly(dimethylsiloxane)-polyimide (PDMS/PMDA–ODA) blends followed by surface modification and deposition of a second layer of polyimide precursor chemicals. The method is based on the micro-phase separation characteristics of these blends to yield surfaces that have PDMS-like character. Upon modification with UV/ozone treatment, a surface that is essentially SiO _x and hydrophilic in nature is produced. This surface is amenable to reaction and deposition of a second polyimide layer from polyimide precursors. The thicker polyimide layer has enhanced adhesion between the original layer of the blend and the new polyimide layer and this approach finds extensive applications for products that require thick polymer layers. Changes in surface energy for various blend compositions were monitored by measurement of advancing contact angle with de-ionized water. Contact angle for unmodified polyimide films was on the order of 70° and it increased to about 104° after blending with PDMS and curing. UV/ozone treatment reduced the contact angle of the doped polyimide to less than 5°. X-ray photoelectron spectroscopy (XPS) and angle resolved XPS (ARXPS) measurements were used to monitor the chemical compositions of the various surfaces. High-resolution XPS spectra in the Si2p region confirm the transformation of O–Si–C bonds in PDMS to SiO _x , where x is about 2. Scanning electron microscopy (SEM) of some selected samples shows that the blends contain phase separation of the polymers at the surfaces of the samples. Atomic force microscopy (AFM) of siloxane-free polyimide, and PDMS/PMDA–ODA blends both prior to and after UV/ozone exposure, show that the films are essentially flat at short treatment times (less than 60 min). AFM also reveals the separation of PDMS into micro-domains at the cured film surface and throughout the layer below the surface of the blended films. Adhesion of a subsequently deposited polyimide layer to the modified polyimide surface was found to be greatly improved when compared to the adhesion obtained for deposition onto a pristine polyimide surface.     

Surface modification of a flexible polyimide film using a reactive fluorinated polymer nanosheet

This paper describes an effective approach to surface modification of a flexible polyimide film using a reactive fluorinated polymer nanosheet. N-(1H,1H-pentadecafluorooctyl)methacrylamide copolymers containing carboxyl group as a reactive moiety form stable monolayer on the water surface and highly ordered reactive polymer nanosheets can be fabricated by the Langmuir-Blodgett technique. This reactive fluorinated polymer nanosheet was utilized to modify the surface properties of polyimide film through its immobilization using thermal treatment. The modification process was studied by X-ray photoelectron spectroscopy (XPS) and modified PI surface was characterized by contact angle measurements and atomic force microscopy (AFM).     

低温等离子体改性铝合金及其表面性质的研究

通过在铝合金表面制备等离子体聚合物薄膜以减少蛋白质吸附,提高铝合金生物相容性.采用四乙二醇二甲醚为有机试剂,在电子回旋共振低温微波等离子体条件下,在铝合金表面制备了一层涂层,用X-ray光电子能谱、衰减全反射红外光谱和血浆蛋白吸附试验对涂层进行分析表征.结果表明:铝合金表面沉积的涂层均匀、致密,其化学组成为类PEG结构,主要聚集大量碳氢和碳氧极性键;与改性前相比,等离子体沉积在铝合金表面的类PEG涂层能够有效抵抗蛋白质吸附.     

Effect of UV/ozone treatment on interactions between ink-jet printed Cu patterns and polyimide substrates

In this study, we apply UV/ozone treatment to modify the surface properties of polyimide substrate and investigate the effects of UV/ozone treatment on surface properties of polyimide and the morphologies of ink-jet printed Cu patterns. Wettability of polyimide surface is enhanced by UV/ozone treatment as confirmed by contact angle analysis and XPS results. The change in wettability affected droplet sizes and morphologies of ink-jet-printed lines. The average droplet size increased from 26.8 μm on untreated polyimide to 42.5 μm after UV/ozone treatment. Furthermore, irregular patterns of coexisting beads and short lines were observed in untreated polyimide film, despite minimal overlap of dots. In contrast, patterns that were ink-jet printed on polyimide film that was modified by UV/ozone for 1 h showed continuous lines with straight edges.     

Surface properties of aromatic polymer film during thermal treatment

Aromatic polyimide films are processed from polyamic acid solutions. This process involved the simultaneous loss of solvent and chemical conversion of polyamic acid to polyimide, and implied structural reorganization which led to changed physical properties. Polymer films generated from benzophenonetetracarboxylic dianhydride and 4,4′-diamino-3,3′-dimethyl diphenylmethane have been investigated at different stages of thermal treatment. The surface polarity, which was determined by the presence of polar COOH and CONH groups, changed during polyamic acid thermal treatment. These polar groups were removed step by step by imidization process leading to the modification of the physical properties of the polymer film.