Surface modification of PET films by atmospheric pressure plasma-induced acrylic acid inverse emulsion graft polymerization

In order to make polyester film surface hydrophilic, atmospheric pressure plasma jet (APPJ) is used to activate the film surface first followed by inverse emulsion grafting polymerization of acrylic acid (AA). The graft ratio and wettability test reveal that the effectiveness of APPJ on initiating graft polymerization increases with increasing plasma treatment duration and helium flow rate. As the jet-to-substrate distance increases, the graft efficiency goes through a maximum at 2 mm. When oxygen is added to the plasma treatment gas, the graft efficiency decreases substantially. Fourier transform infrared spectrometry (FTIR) analysis shows new bands appearing at 2500-3600 cm^− 1 and 1546 cm^− 1 for the plasma-grafted samples. Scanning electron microscopy (SEM) results show that the grafted layer is built with a large number of spherical particles at submicron or even nanoscale. With a high graft ratio, agglomeration of neighboring particles becomes more pronounced, and eventually a relatively continuous graft layer is obtained with a corresponding surface contact angle of 5° which is considered superhydrophilic.     

Surface modification of a polyester non-woven with a dielectric barrier discharge in air at medium pressure

In this paper, a polyester non-woven is plasma treated with a dielectric barrier discharge (DBD) in air at medium pressure (5.0 kPa) and at different discharge powers. Results show that an increasing power leads to a better plasma treatment of the sample. The barrier discharge is characterized by a voltage and current waveform, by a Lissajous figure and by Lichtenberg figures. The surface properties of the plasma treated samples are examined using X-ray photoelectron microscopy (XPS) and scanning electron microscopy (SEM). XPS analysis reveals that surface oxidation by the formation of oxygen-containing functional groups enhances the surface wettability. SEM analysis shows that the sample is not etched by the used barrier discharge. This is due to the low surface energy density of the DBD used in this paper. Therefore, a DBD in air at medium pressure provides an efficient modification of the chemical surface properties of textiles without destroying the physical structure.     

Surface modification and characterizations of basalt fibers with non-thermal plasma

Atmospheric-pressure non-thermal plasmas have been increasingly promoted for polymer surface modification. In this paper, atmospheric-pressure plasmas of oxygen, argon, hydrogen and mixture gases of nitrogen and hydrogen were used to surface modification of basalt fibers in order to illuminate their chemical durability, surface active groups and roughness etc. The plasma-induced surface changes on morphologies and active groups were characterized by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The results exhibited a remarkable increase in chemical stability and excellent adhesion, accompanied by extensive etching and by the implantation of both oxygen- and nitrogen-containing polar groups such as NH₂, OH and so forth. Etching of oxygen was mainly a consequence of ion bombardment, yielding low molecular weight and roughness, while surface chemical modifications of mixture of hydrogen and nitrogen were mainly due to the action of neutral species on the plasma-activated basalt fiber surface. The possible formation mechanism of functional groups on the basalt fiber surface was presented.     

Surface modification of polyester fabrics for inkjet printing with atmospheric-pressure air/Ar plasma

Without any preprocessing, polyester fabric has a lower ability to hold on water and inks due to the smooth morphology and chemistry property of polyester fibers. Therefore, patterns directly printed with pigment inks have poor color yields and bleed easily. Plasma surface treatment of polyester fabrics was carried out in composite atmosphere with air and 10% Ar under different experimental conditions. After plasma treatment the samples were printed with pigment inks. The results show that surface-modified polyester fabrics exhibited enhanced color yields and excellent pattern sharpness. SEM and XPS analyses indicated that this improved color performance was mainly contributed by not only the etching effect but also oxygen-containing polar groups induced onto fiber surfaces through plasma treatment. Thereby the surface modification of polyester fabrics using air/Ar plasma offers a potential way to fabric pretreatment for pigment inkjet printing with the advantages of environmental friendly and energy saving over traditional pretreatment methods.     

Surface modification of austenitic stainless steel with plasma nitriding for biomedical applications

In the present study, plasma nitriding of AISI type 303 austenitic stainless steel (SS) specimens was performed using a microwave system. The nitrided layers were characterized by performing scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and a Vickers microhardness test. The antibacterial activities of the nitrided layers were evaluated. XRD and TEM showed that a single γ_N phase was formed by plasma nitriding at the plasma power of 700 W and 450 °C. The analytical results demonstrated that the hardness of type 303 specimens could be enhanced by plasma nitriding because of the formation of the γ_N phase. A bacterial test also demonstrated that the nitrided layer exhibited excellent antibacterial properties.     

Surface modification of polyurethane and silicone for therapeutic medical technics by means of electron beam

Surface modification technologies are gaining growing acceptance for treatment of implant materials to enhance biocompatibility. Our examinations focus on polyetherurethane and silicones, two typical flexible implant materials, which we have modified by non-thermal electron beam processing. Advantages of this method are the adjustable degree of modification as well as the simultaneous sterilizing effects.The polymer surfaces were characterized with regard to wetting behavior, surface energy, chemistry and morphology. The cell adhesion was examined too. The results reveal that the electron beam is a useful tool for surface modification of polymers.     

Surface modification of silica glass by CHF3 plasma treatment and carbon negative-ion implantation for cell pattern adhesion

We have investigated a method for the patterning of cell adhesion on a silica glass by using two-steps of surface modification processes of CHF₃ plasma treatment and negative-ion pattern implantation. For the first step, exposure of CHF₃ plasma to silica glass (SG) was used to obtain hydrophobic surface, leading to eliminate cell-adhesion property. After treatment with RF power of 20 W and exposure time of 120 s, the hydrophobicity was occurred from the increase in contact angle of SG from 43° to 88° and its reason based on XPS analysis was due to formations of C―F, C―F₂, and C―F₃ bonds, so-called fluorocarbonated bonds. Culture of mesenchymal stem cells (MSC) and rat adrenal pheochromocytoma cells (PC12h) showed the degradation of cell adhesion property on the plasma-treated SG surface. For the second step, carbon negative-ion implantation into the hydrophobic fluorocarbonated-SG surface was used to pattern the hydrophilic region, leading to enhance cell adhesion property. The contact angle of C-modified surface decreased to 76° at conditions of 15 keV and 1 × 10¹⁵ ions/cm². XPS showed that the hydrophilicity was due to reduction of C―F_x bonds and formation of C―O and C═O bonds. After 3 days culture of MSC and PC12h on the C-implanted surface of the plasma-treated SG, a fairly good adhesion patterning of both cells was obtained on the ion-implanted regions.     

Surface modification of titanium by pack cementation treatment using calcium phosphate powders for biomedical applications

The surface modification of commercially pure titanium by pack cementation treatment using hydroxyapatite (HAp) or tetracalcium phosphate (TTCP) powder was investigated for temperatures ranging from 773 K to 1073 K. An HAp phase was detected on the surface of the titanium substrates after pack cementation treatment at temperatures of 973 K and 1073 K. After treatment using HAp and TTCP powders, a reaction layer with small HAp particles and pores containing small HAp particles, respectively, was observed. Apatite crystallites with a network pattern formed on the pack-cementation-treated titanium substrates after the substrates were immersed in Kokubo solution for 43.2 ks; such rapid apatite formation suggests that pack cementation treatment improves the biocompatibility of titanium.     

Surface functionalization of ceramic membranes with 3-aminopropyl groups using the sol-gel method

Planar ceramic Al₂O₃ membranes were functionalized with polysiloxane and polysilsesquioxane layers containing 3-aminopropyl groups using the sol-gel method. SEM images show the formation of polysiloxane or polysilsesquioxane layers on the membrane surfaces with the thickness of 0.35 and 4.4 nm, respectively. Infrared spectroscopy data confirmed the presence of the polysiloxane network and functional groups introduced during the synthesis. Measurements of the contact angles on the membrane surfaces showed that the hydrophilicity of the active layer is practically independent of the type of the structuring agent (tetraethoxysilane or 1,2-bis(triethoxysilyl)ethane), and the introduction of the methyl groups increases the hydrophobicity of the surface layer. According to the filtration studies, all functionalized membranes are capable of retaining Cu(II) ions during filtration of diluted solutions due to the complexation of the amino groups in the selective layer with these ions.     

等离子表面合金化层摩擦磨损性能研究

利用辉光等离子渗金属技术,在低碳钢表面进行Ti-N和W-Cr合金元素共渗,达到改善其表层耐磨性的目的.经分析,结果表明:Ti-N合金元素共渗层形成了氮化钛沉积层和扩散层,厚度在10μm以上,平均硬度达到HV2300;Mo-Cr共渗层厚度在100μm以上,渗入合金元素Cr、Mo,表面含量分别达到4%和12%左右,随后进行的超饱和渗碳使表面含碳量达到2.0%以上,淬火及回火后表面硬度达到HV1300,超过一般冶金高速钢.Ti-N合金元素共渗层磨损曲线较平稳,平均摩擦系数较小,耐磨性比Mo-Cr共渗层要好.     

Influence of aging behavior of Armos fiber after oxygen plasma treatment on its composite interfacial properties

This work concerns the aging behavior of Armos fiber and Armos fiber reinforced poly (phthalazinone ether sulfone ketone) (PPESK) composite after oxygen plasma treatment. Armos fiber surface chemical composition, surface morphology and roughness, and surface wettability as a function of storage time in air after oxygen plasma treatment were measured by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and dynamic contact angle analysis (DCAA) system, respectively. The fiber surface aging behavior could be detected obviously in chemical composition and surface wettability, whereas the surface morphology and roughness remained nearly stable after storing in air as long as 10 days after oxygen plasma treatment. The effects of surface aging behavior after oxygen plasma treatment on Armos fiber reinforced PPESK composite interfacial properties were evaluated by interlaminar shear strength (ILSS) test and humid resistance measurement. It was found that the values of ILSS reduced and the composite humid resistance properties decayed. The polar functional groups that were reoriented from the surface into the bulk of the fibers or moved away from the fiber surfaces, maybe responsible for the weak interfacial strength between the fiber and the matrix in composite system.     

Surface modification of platinum with copper and by plasma-chemical treatment and the effect on H-Pt bond energy

Kinetics of H₂ desorption from the surface of a platinum catalyst applied to silica gel, as well as from the surface of the same catalyst modified with a copper additive, is studied. Desorption of hydrogen was studied both before and after the treatment of the catalyst in the electric glow discharge of argon or oxygen or in the high-frequency H₂ plasma. The H-Pt bond energy was found to increase upon the introduction of copper additive and decrease upon the plasma-chemical treatment of copper-platinum specimens. In the latter case, the size of metal particles increases and the microstrain in them decreases. The observed changes in H-Pt bond energy are explained by the change in the electronic state of the surface and the increase in the number of metal structure defects.     

Self-healing protective films prepared on zinc electrodes by treatment in a cerium(III) nitrate solution and modification with sodium phosphate and calcium or magnesium nitrate

Self-healing protective films were prepared on a zinc electrode by treatment in a Ce(NO₃)₃ solution and modification with Na₃PO₄ and Ca(NO₃)₂ or Mg(NO₃)₂. The protective and self-healing abilities of the films were examined by polarization measurements and observation of pit formation after the electrode was scratched with a knife-edge and immersed in aerated 0.5 M NaCl for many hours. The protective efficiency of the film modified with Ca(NO₃)₂ was higher than that of the film without Ca(NO₃)₂ but the self-healing ability of the former film was not sufficiently high during the prolonged immersion. Mechanisms of the protective and self-healing activities were discussed using X-ray photoelectron spectroscopy and electron-probe microanalysis.     

Surface modifications of polycarbonate (PC) and acrylonitrile butadiene styrene (ABS) copolymer by treatment with atmospheric plasma

Two engineering thermoplastic polymers (polycarbonate, PC, and acrylonitrile butadiene styrene copolymer, ABS) were treated with atmospheric plasma torch using different treatment rates (1, 5 and 10 m/min). The modifications produced by the treatment were analysed by contact angle measurements, XPS, SEM and ATR-IR spectroscopy. Particular emphasis was placed on the ageing (up to 30 days) after atmospheric plasma treatment on both polymers.The slower the atmospheric plasma treatment, the greater the wettability of the treated polymers. The decrease in water contact angle was mainly ascribed to a significant increase in oxygen content due to the formation of carboxylic and hydroxyl groups and a decrease in the carbon content on the polymer surfaces. After natural ageing, there was an increase in the water contact angle, although the values of the untreated polymer surface were never reached.     

Fe-Ni-B超细非晶粉表面不同处理后的组成和性能

本文对Fe—Ni—B超细非晶粉表面加以单宁酸和重铬酸钾处理，并采用了XPS和TEM等对处理后超细粉的表面组成和结构进行了分析。结果表明，单宁酸和重铬酸钾处理均可以提高Fe—Ni—B超细非晶粉的饱和磁化强度，但后者的提高幅度远大于前者。原因在于二种表面处理均使超细粉的表面状态发生了有利于饱和磁化强度的变化，在表面形成了复合型氧化物NiFe2O4；而重铬酸钾处理还在超细粉表面形成了致密的Cr2O3层，阻挡了氧原子从表面向体内的扩散，减少了超细粉的氧化态数量，而使其饱和磁化强度得以大大提高。     

碳化硼薄膜的电子束蒸发制备及表面分析

采用电子束蒸发技术制备碳化硼薄膜,利用X射线衍射(XRD)分析了薄膜的结构,测量了薄膜的X射线光电子能谱(XPS),并利用原子力显微镜(AFM)对薄膜进行表面分析.XRD结果表明:薄膜的结晶性随着衬底温度的升高逐渐转好,在较低的衬底温度下制备出多晶碳化硼薄膜.XPS分析得到了碳化硼薄膜表面的化学成分和结构特性,其主要成分为B_4C.AFM结果表明,薄膜表面光滑平整、均匀致密,随着衬底温度的升高薄膜均方根(RMS)粗糙度逐渐增大.     

Improvement of adhesion of conductive polypyrrole coating on wool and polyester fabrics using atmospheric plasma treatment

In this paper wool and polyester fabrics were pretreated with atmospheric plasma glow discharge (APGD) to improve the ability of the substrate to bond with anthraquinone-2-sulfonic acid doped conducting polypyrrole coating. A range of APGD gas mixtures and treatment times were investigated. APGD treated fabrics were tested for surface contact angle, wettability and surface energy change. Effect of the plasma treatment on the binding strength was analyzed by studying abrasion resistance, surface resistivity and reflectance. Investigations showed that treated fabrics exhibited better hydrophilicity and increased surface energy. Surface treatment by an APGD gas mixture of 95% helium/5% nitrogen yielded the best results with respect to coating uniformity, abrasion resistance and conductivity.     

Surface physico-chemistry study of an austenitic stainless steel: Effect of simple cold rolling treatment on surface contamination

The surface physico-chemistry properties of stainless steel and the effects of a cold rolling treatment were investigated. X-ray photoelectron spectroscopy (XPS) analyses were carried out on rolled surfaces at different rates. Thus, by characterizing passive film chemistry and contamination layer, the modifications due to this treatment were quantified, in particular an increase of the ratio (Fe/Cr)_oxide is evidenced with the level of the cold rolling treatment. Moreover, based on an angle resolved analysis, a new model where the contamination layer is represented as isolated parts was developed in order to describe the geometry of this carbon contamination. XPS experiments show an iron enrichment of the passive film during the cold rolling treatment, which seems to be explained by a surface heating during the mechanical treatment. Therefore, the new island model puts in evidence the effects of ageing time and surface condition on the geometry of carbon contamination. Hence, cold rolling increases the thickness and the recovery of carbon contamination on the stainless steel surface.     

C61900铜合金表面镀渗复合工艺改性

对C61900铜合金镀钛-渗碳复合工艺进行了研究,首先采用了闭合场非平衡磁控溅射镀钛膜,再利用等离子体渗碳在铝青铜合金表面制备出了镀钛渗碳改性层;然后对改性层表面进行了硬度、摩擦磨损、SEM、EDS、XRD表征。结果显示：最佳等离子渗碳工艺参数为650 ℃保温时间6 h,将铝青铜表面硬度提高到了300 HV0.01以上,是铝青铜基体的3.8倍以上,并使其磨损率降低了近90%,解决了C61900铜合金表面硬度低耐磨性差的问题。