低温等离子体技术在生物材料表面改性中的应用

综述了低温等离子体技术在生物材料表面改性中的应用.概述了低温等离子体分类、特征及其与生物材料表面作用的机理;介绍了低温等离子体聚合、低温等离子体处理、低温等离子体接枝聚合对生物材料表面改性的原理以及它们在生物材料领域中的最新应用进展和应用前景.     

等离子改性条件对PEGDA/HEMA凝胶亲水性及表面能的影响

采用氩等离子对聚乙二醇双丙烯酸酯(PEGDA)/甲基丙烯酸-2-羟基乙酯(HEMA)共聚物凝胶进行表面改性,对膜材料进行了光电子能谱(XPS)分析,并讨论了等离子处理时间及功率对凝胶亲水性及表面能的影响。研究结果表明,经等离子处理后凝胶表面引入了含氧极性基团,氧的含量从未处理的23%增加到26%,使材料亲水性得到改善;由于引入极性基团,材料的表面能随等离子处理时间和功率的增加而增加,从未处理前的45.9 mJ/m2增加到72.5 mJ/m2,极性力分量γPs随等离子体处理功率和时间的变化规律与表面能γs基本一致。     

空心阴极等离子体放电结构的优化设计

 低温等离子体表面处理可以有效克服液相处理法存在的环境污染、耗能大和成本高的缺点,对材料表面进行清洗、活化和接枝处理,而设计一个合理的低温等离子体放电结构能够较好地改进表面处理的质量．通过建立CRFHCP空心阴极等离子体放电的数学模型,分析影响低温等离子体放电的关键因素,并设计了不同电极配置方式、样品位置和不同远区空心阴极结构的众多方案．通过接触角测定、表面能计算、SEM照片等方式,对不同方案下处理前后的疏水性PP薄膜形态结构进行表征分析．实验结果发现：远区径向喷嘴式空心阴极等离子体放电结构处理的薄膜表面比其他处理方式具有较小的接触角和较大的表面能．这表明采用优化设计的CRFHCP空心阴极等离子体放电结构,可以较其他结构更为有效地改善材料表面的亲水性能．     

Structural changes of a pyrolytic graphite surface oxidized by electrochemical and plasma treatment

Pyrolytic graphite (PG) surfaces have been oxidized by electrochemical and oxygen plasma treatment. The oxidized PG surfaces have been studied by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared attenuated total reflection spectroscopy (FT-IR-ATR). Oxidation caused by the plasma treatment results in a small increment of the oxygen: carbon (O/C) ratio, compared to electrochemical treatment. Moreover, the increment of the O/C ratio for the plasma treated edge surface is smaller than that for the plasma treated basal surface. A steep gradient in oxygen concentration exists within the edge subsurface of PG for samples subjected to severe electrochemical treatment, as compared to those samples subjected to plasma treatment. For the electrochemical treatment, carbonyl, carboxyl, ester and lactone groups are introduced to the edge surface following relatively severe treatment. The ratio of ester and lactone groups to carboxyl groups increases with the extent of electrochemical treatment. For plasma treated samples, other types of oxygen-containing groups, which are probably keto-enol groups, are added to the edge surface, unlike during electrochemical treatment.     

Holzoberflächenmodifikation mittels Atmosphärendruckplasma

Plasma surface modification of wood and wood‐based materials In this article, plasma technical, analytical and application relevant aspects of the plasma treatment of wood and wood‐based materials are presented. With the help of surface energy determinations and adhesion tests it is shown that the surfaces of wood and wood‐based materials can be changed for specific applications. Surface characteristics, which are application‐technological interesting for a later coating or adhesion, can be specifically generated with the use of air plasma. With surface energy determinations of wood and wood‐based materials, a significantly increased polar part of surface energy could be detected after a plasma treatment. Atomic force microscopy analyses of wood composites show that a plasma treatment with the use of ambient air effects an abrasion and a changed surface roughness. Tensile tests and shear tests of coated or adhered wood‐based materials with a plasma treatment show a clearly increased adherence.     

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。     

The mechanism of adhesion and printability of plasma processed PET films

Of the several techniques available for the surface modification, plasma processing has proved to be very appropriate. The low temperature plasma is a soft radiation source and it affects the material only over a few hundred Å deep, the bulk properties remaining unaffected. Plasma surface treatment also offers the advantage of greater chemical flexibility. PET films are widely used for packaging and electrical insulation. The studies of adhesion and printability properties are important. In the present study PET films are treated in air plasma for different time of treatment. The improvement in adhesion is studied by measuring T-peel and Lap shear strength. In addition, printability of plasma treated PET films is studied by cross test method. It has been found that printability increases considerably for plasma treatment of short duration. Therefore it is interesting to study the surface composition and morphology by contact angle measurement, ESCA and AFM. Surface energy and surface roughness can be directly correlated to the improvement in above-mentioned surface related properties. It has been found that the surface oxidation occurs containing polar functional groups such as C-O, COO. A correlation of all such observations from different techniques gives a comprehensive picture of the structure and surface composition of plasma treated PET films.     

冷等离子体处理对涤纶纤维表面性能的影响

采用冷等离子体技术处理涂纶纤维,利用ESCA分析了冷等离子体处理前后的纤维表面元素组成,官能团类型的变化,通过比较处理前后浸润性,涂纶纤维／环氧复合材料的层间剪切强度,研究了冷等离子处理对涤纶纤维表面性质的影响,结果表明：绦纶纤维经冷等离子处理后表面含氧的极性基团增加,纤维表面的浸润性显著改善,涤纶纤维／环氧复合材料界面性能增强。     

Contact angle analysis of low-temperature cyclonic atmospheric pressure plasma modified polyethylene terephthalate

Polyethylene terephthalate (PET) films are modified by cyclonic atmospheric pressure plasma. The experimentally measured gas phase temperature was around 30 °C to 90 °C, indicating that this cyclonic atmospheric pressure plasma can treat polymers without unfavorable thermal effects. The surface properties of cyclonic atmospheric pressure plasma-treated PET films were examined by the static contact angle measurements. The influences of plasma conditions such as treatment time, plasma power, nozzle distance, and gas flow rate on the PET surface properties were studied. It was found that such cyclonic atmospheric pressure plasma is very effective in PET surface modification, the reduced water contact angle was observed from 74° to less than 37° with only 10 s plasma treatment. The chemical composition of the PET films was analyzed by X-ray photoelectron spectroscopy (XPS). Atomic force microscopy (AFM) was used to study the changes in PET surface feature of the polymer surfaces due to plasma treatment. The photoemission plasma species in the continuous cyclone atmospheric pressure plasma was identified by optical emission spectroscopy (OES). From OES analysis, the plasma modification efficiency can be attributed to the interaction of oxygen-based plasma species in the plasma with PET surface. In this study, it shows a novel way for large scale polymeric surface modification by continuous cyclone atmospheric pressure plasma processing.     

Tribological behaviors of plasma-treated carbon composite grooved surfaces

The tribological behavior of carbon epoxy composites whose surfaces have many small grooves of 100 μm width were compared with respect to plasma treatment duration under dry sliding conditions. The surface coating material on the grooved surface was high-density polyethylene (HDPE) and suitable plasma treatment time for grooved composite surface for atmospheric pressure plasma system was experimentally investigated by measuring the friction coefficient and wear volume. The wear morphology of the composites observed with a scanning electron microscopic (SEM) revealed that the surface coating layer on the grooved surface significantly improved the wear resistance and the plasma treatment can improve the durability of the coating layer.     

钛表面处理技术的研究现状

在钢铁材料中得到成功应用的传统表面技术,在钛表面处理上也得到了较广泛的应用,但传统的表面技术存在着许多不适应于钛材处理的技术壁垒,因此,针对钛材料的特殊性能发展起来的液相等离子体处理技术、等离子表面冶金技术、钛电极涂层技术、钛生物涂层技术、钛建筑材料的表面处理技术等成为钛材表面处理技术新的发展方向。主要综述了传统表面技术和液相等离子体处理技术、等离子表面冶金技术2种新技术在钛材表面上应用的研究成果。     

Modification of pyrolytic graphite surface with plasma irradiation

The effects of oxygen plasma treatment on the basal and edge surfaces of pyrolytic graphite have been investigated and compared with those of electrochemical treatment on their surfaces. The structural changes caused by the plasma and electrochemical treatments have been characterized by laser Raman and X-ray photoelectron spectroscopies. For the basal surface the plasma treatment causes the slight destruction of the graphitic structure, whereas for the edge surface it causes no marked destruction of the graphitic structure unlike the electrochemical treatment. The amount of surface oxygen both on the basal and edge surfaces increases after the plasma treatment. In particular, for the edge surface, a high surface oxygen concentration can be attained in a short treatment time. In addition, carbonyl-type groups appear to dominate in the plasma-treated basal and edge surfaces over -O- type groups. It can be concluded that oxidation by the plasma treatment is restricted to the vicinities of the surfaces and does not proceed to the internal structure of graphite, unlike the electrochemical treatment.     

The effect of surface treatment on the performance improvement of carbon fiber/polybenzoxazine composites

The effects of surface treatments, such as oxygen plasma and nitric acid treatment, on the mechanical properties of carbon fiber (CF)/polybenzoxazine composites were investigated. Interlaminar shear strength (ILSS) and flexural strength of CF/polybenzoxazine composites were measured and correlated with surface area and surface functionality. Both oxygen plasma treatment and nitric acid treatment were efficient in the enhancements of the ILSS and flexural strength of CF/polybenzoxazine composites. However, nitric acid treatment was more efficient than oxygen plasma treatment due to large increment of surface roughness. Cohesive failure was observed in surface treated composite due to adhesion improvement.     

Nano-scale texturing of borosilicate glasses using CF4-based plasma discharge for application in thin film solar cells

Random plasma treatment techniques were used as a texturing method to reduce the surface reflection of glass substrates in thin film solar cells. Various gas mixtures were used for the plasma discharge in an effort to examine the texturing mechanism. Using a plasma treatment comprising CF4/O2 and CF4/Ar with a gas flow ratio of 1 to 2, the surface reflectance could be decreased to 6.83% and 6.82%, respectively. The surface treatment was very effective with the use of a low RF power of 50 W and an optimal time of 5 min. It is considered that the optical characteristics of the glass substrate are highly correlated to its surface morphology which can be produced not only through nano-scale chemical reactions with radicals but also through ion flux bombardment.     

Surface modification of an aramid fibre treated in a low-temperature microwave plasma

The surface modification of an aramid fibre treated in a low-temperature microwave (mw) plasma was investigated. Three different plasma gases, oxygen, argon and ammonia, were used to achieve different surface modifications during fibre treatment. The modification of the fibre surface was analysed with electron spectroscopy and electron microscopy. The influence of the surface modification on the fibre-matrix interaction was inspected by measuring the interlamellar shear strength of the composites and the pull-out strength of a fibre bundle in model composites. The process gas and thus the kind of plasma has no significant influence on the fibre modification resulting from plasma treatment. It was shown that a fibre cleaning with subsequent surface ablation is the dominate modification process during mw plasma treatment, independent of the process gas. The degree of surface cleaning and removal of a contamination layer strongly depended on the treatment range. No incorporation of oxygen or nitrogen containing functional groups was observed. This was explained with the composition of the process gas. The improvements of the composite properties demonstrate the advantage of the mw plasma treatment as a fast, environmentprotected, cost-efficient process for fibre modification.     

氧气DBD等离子体处理PBO纤维表面及其对双马树脂基复合材料界面性能的影响

采用氧气介质阻挡放电(DBD)等离子体处理PBO纤维表面,用以改善PBO纤维与双马来酰亚胺(BMI)树脂之间的界面粘结性能。结果表明,用氧气等离子体处理PBO纤维能大幅度提高PBO/BMI复合材料的层间剪切强度(ILSS)值,最佳处理条件为功率30 W/m³、时间24 s,ILSS值从43.9 MPa提高到62.0 MPa。经过氧气DBD等离子体处理的PBO纤维其表面的氧含量明显提高,氮含量变化不大,甚至在过度处理时降低;官能团-O-C=O基团的含量从0提高到3.16%,-C-O-的含量也明显提高;在氧气DBD等离子体处理后的PBO纤维表面产生大量凹凸不平和沟壑,使纤维表面的粗糙度提高。而表面氧含量的提高和表面形貌与粗糙度的变化,是PBO/BMI复合材料ILSS值提高的重要原因。单丝拉伸实验结果表明,适当的DBD等离子体处理不会对PBO纤维表面产生不良影响,不影响其在复合材料中的作用。     

Plasmaprozesse für 3D‐Formteile

Plasma treatment and coating processes for 3D parts Many articles of our daily use are only able to feature their outstanding performance due to innovative plasma surface treatments. Semiconductor components like flat panel displays, solar panels, DVD / Blu‐ray Discs, as well as optical components, coated glass panes, cutting tools and other components with reduced wearing are just a few examples. One important quality feature is to reach uniform properties over the entire surface to be treated. In case of planar or slightly curved surfaces this can be relatively easily achieved by using common plasma sources. For complex 3D parts, the effort required for uniform surface treatments greatly increases, and complex movements of the 3D parts are often required to achieve uniformity. This article deals with the plasma surface treatment and plasma coating of such complex 3D parts referring to some selected examples.     

Modification of polypropylene surface by CH<Subscript>4</Subscript>–O<Subscript>2</Subscript> low-pressure plasma to improve wettability

The aim of this work is to study the effect of surface treatment of a polypropylene film with low-pressure plasma using CH₄–O₂ mixture gas in an 80:20 ratio. The effect of the variation of the plasma treatment conditions has been studied to optimize the plasma effects. The film wettability has been analyzed by the study of the variation of free surface energy and its polar and dispersive components. The surface functionalization of the PP film was also analyzed by X-ray photoelectron spectroscopy (XPS) and attenuated total reflectance infrared spectroscopy (FTIR-ATR) analysis. The surface topography was analyzed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The CH₄–O₂ plasma treatment induces the ablation inherent of a traditional plasma treatment and polymerization mechanisms to take place simultaneously at the treated surface. The PP film treated with CH₄–O₂ plasma shows a remarkable improvement on the surface free energy mainly caused by surface functionalization as XPS reveals. Slight changes in surface topography are observed, but they do not contribute in a significant way to improve wettability.     

RF-Ar等离子体对聚乙烯薄膜的表面改性

采用射频辉光放电氩等离子体,在工作压力为20 Pa、功率为30W的条件下对低密度聚乙烯薄膜进行了不同时间的表面处理。借助静态接触角、X射线光电子能谱仪、原子力显微镜、差示扫描量热仪对薄膜改性前后的性能进行了表征及分析。研究结果表明:氩等离子体短时间(20 s)处理便可以有效改善薄膜表面的亲水性,处理时间大于20 s后接触角的变化并不明显;处理后的薄膜表面引入了大量的含氧及少量的含氮官能团;薄膜表面所形成的交联层阻挡了极性基团的翻转,有效延长了接触角的时效性;薄膜的表面形貌和结晶度发生了变化。     

Study of oxygen plasma pre-treatment of polyester fabric for improved polypyrrole adhesion

In this work, we have systematically studied the improvement of binding of polypyrrole with polyethylene terephthalate (PET) thin films and fabrics using low pressure oxygen plasma. A range of plasma treatment times were employed to investigate plasma induced effects on surface roughness, surface chemistry and hydrophilicity. Modifications of PET films were studied with respect to surface morphology by means of atomic force and scanning electron microscopy. Chemical effects of plasma treatment were studied using X-ray photoelectron spectroscopy. Results showed that both the increase in surface functionalisation by carboxylic groups and formation of nano size roughness contributed to improved adhesion and conductivity.