Ausgasungsmessungen von Metallen,Plasten und Kohlenstoff

A device for gas-selective outgassing measurements is demonstrated and the necessary handling of the data was described. In this way measured partial and total outgassing rates of some metals, plastics and graphite after different pretreatments are shown. The outgassing rates were discussed qualitatively and quantitatively. A throuput correction was made for every gas. For metals the influence of outgassing reducing coatings and effect of cleaning procedures were investigated. In the case of plastics the part of hydrocarbons of the total outgassing rate was studied. For graphite samples the amount of hydrogen outgassing was dicussed.     

铬及铍表面辉光放电清洗的研究

本文对He辉光放电清洗后的铬（Cr）表面杂质去除情况和铍（Be）样品真空出气量变化进行了实验研究。使用场发射扫描电镜和表面质量测量仪对比观察了不同放电参数处理后的Cr样品表面，结果显示在放电功率为200～300W、放电室压强为1～10Pa、清洗时间为10-20min时可较好地清除表面杂质和降低表面粗糙度；对辉光放电处理前后Be样品出气情况的实验对比结果显示，清洗后1h内总出气量约降为清洗前的1／6。     

Titannitrid als gasabgabereduzierende Schicht auf Edelstahl

TiN films were deposited on stainless steel samples using a new coating procedure, the so-called modified pulse arc process. The influence of titanium nitride films on the outgassing rate was studied and the obtained results were discussed. Measurements of the outgassing rate carried out with untreated stainless steel samples and with stainless steel samples coated with titanium nitride by DC arc process are compared with the results obtained from the samples coated with the modified pulse arc process in order to get information about the influence of the coating procedure on the outgassing rate.     

An approach to mesoporous silica synthesis into α-Al2O3-mullite cavities

MCM-41 mesostructured materials were prepared by confined space synthesis into the cavities of αAl₂O₃-mullite supports by hydrophobing the matrix surfaces prior to be immersed in a precursor solution. The obtained samples were characterized by X-ray Powder Diffraction (XRPD), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM) and Nitrogen Adsorption techniques. XPS results demonstrated the effectiveness of hexamethyldisilazane (HMDS) to modify the surface properties through hydrophobic treatment. SEM images of the starting supports and the final products show well-defined agglomerates of mesostructured materials on the surfaces of mullite-corundum cavities.     

Surface treatment effect in thermoplastic rubber and natural leather for the footwear industry

This paper aims to analyze the peel strength of an adhesive joint with various types of surface treatments. In the shoe industry, the adhesive properties are very important to ensure the quality of manufacture of the shoe, thus, to better understand the behaviour of the adhesive joint, it is important to analyze the peel resistance in order to adjust the manufacturing process. In this work, natural leather, thermoplastic rubber (TR) and a non‐structural, solvent based, polyurethane adhesive were considered. The influence of the application of chemical and/or mechanical surface treatments on substrates in the peel strength of a T joint were analysed. To characterize the surfaces, several test were considered, including Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM) and contact angle measurements. It was found that certain surface treatments are required to obtain an adhesive joint capable of satisfying the minimum strength requirements of the shoes sector.     

Enhanced printability of polyethylene through air plasma treatment

Low-density polyethylene (LDPE) foils were surface-modified by using non-thermal non-equilibrium oxidative air 40 kHz frequency, radiofrequency (RF) and microwave (MW) discharge plasma treatment. The pristine and treated specimens were morphologically and chemically characterised by Scanning Electron Microscopy (SEM) imaging, X-ray Photoelectron Spectroscopy (XPS) and contact angle measurement with surface energy evaluation. In addition, printability and ink adhesion tests were carried out on the samples, and quantitatively appraised by UV–VIS transmission spectroscopy. The overall outcome indicated chemical and physical changes after each treatment, and the improvement of printability. The present approach could serve as a viable and promising method to improve printability of polyethylene.     

Bias enhanced nucleation of diamond thin films in a modified HFCVD reactor

In this study we investigated the nucleation of synthetic diamond thin films on Si substrates by double bias enhanced Hot Filament Chemical Vapour Deposition (HFCVD) method. First, we investigated the influence of the bias voltage and secondly the influence of the nucleation time under different bias voltages. The bias voltage was varied from −120 V up to −220 V as well as the nucleation time was changed from 30 up to 120 min in order to obtain the optimized nucleation conditions for following growth of continuous diamond layer. Samples were analyzed by Scanning Electron Microscopy (SEM) and Raman Spectroscopy. SEM was used for determination of cluster sizes and their distribution on the Si surface, while Raman Spectroscopy for determination and analysis of carbon phases.     

Studies on the corrosion and wear behavior of the laser nitrided biomedical titanium and its alloys

The effects of laser nitriding on surface hardness, corrosion and wear behavior of the conventional biomedical implants such as commercially available pure titanium and Ti–13Nb–13Zr alloy is reported. The influence of alloying elements such as Zr and Nb on nitride formation was also studied by nitriding the newly developed alloy (Ti–13Nb–13Zr). The surface modified samples were characterized using optical microscope (OM), Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS) and X-ray diffraction (XRD) techniques. Corrosion rate, wear rate and coefficient of friction were made under simulated body condition for commercially available pure titanium and Ti–13Nb–13Zr alloy. The high speed processing of these alloys enabled smooth and crack free surface.     

Comparative study on dry etching of polycrystalline diamond thin films

The reactive ion etching (RIE) technique was used to etch polycrystalline diamond thin films. In this study we investigate the influence of process parameters (total pressure, rf power, gas composition) of standard capacitively coupled plasma RIE system on the etching rate of diamond films. The surface morphology of etched diamond films was characterized by Scanning Electron Microscopy and the chemical composition of the etched film part was investigated by Raman Spectroscopy.We found that the gas composition had a crucial effect on the diamond film morphology. The use of CF₄ gas resulted in flatter surfaces and lateral-like etching, while the use of pure O₂ gas resulted in needle-like structures. Addition of argon to the reactant precursors increased the ion bombardment, which in turn increased the formation of non-diamond phases. Next, increasing the rf power from 100 to 500 W increased the etching rate from 5.4 to 8.6 μm/h. In contrast to this observation, the rise of process pressure from 80 to 150 mTorr lowered the etching rate from 5.6 down to 3.6 μm/h.     

Structure of diamond polycrystalline films deposited on silicon substrates

The article presents results of structural studies of polycrystalline diamond thin films deposited by hot filament CVD on silicon substrates. The films were characterized using Scanning Electron Microscopy (SEM), Raman Spectroscopy (RS), Electron Backscattered Diffraction (EBSD), Energy Dispersive Spectroscopy (EDS) and Secondary Ion Mass Spectroscopy (SIMS). Both the EBSD patterns and Raman spectra confirm that the grains visible in the electron micrographs are diamond micro-crystallites. The residual stress in the films is found to be in the range between −4.29 GPa and −0.56 GPa depending on the sample thickness. No evidence of lonsdalite and graphite has been registered in the polycrystalline material of the investigated samples. Evidence of the existence of silicon carbide at the diamond/silicon interface is presented. It is also suggested that an amorphous carbonaceous film covers the silicon surface in the regions of holes in the thin diamond layers.     

Bestimmung von Ausgas- und Desorptionsraten mittels Restgasanalysator

Determination of Outgassing and Desorption Rates by Means of Residual Gas Analysis Especially when using plastic materials in vacuum chambers it is essential to know the amount of gases outgassing from the surface of those materials. Depending on the so-called outgassing or desorption rate one can decide if the proposed plastic material is suited for the desired application and how the vacuum system has to be configured, so that the use of the particular material makes sense. The article will demonstrate by means of 2 examples that there exist temperature-dependent outgassing behaviors of different materials. It also gives an overview of the measuring equipment set up to determine the outgassing rates.     

Reinigung von Vakuumbauteilen für UHV‐ und UCV‐Anwendungen

Cleaning of vacuum components for UHV and UCV applications Ultra‐clean vacuum components and assemblies are fundamental to some cutting edge high‐tech sectors like semiconductor industry, particle accelerators, and surface analytics. Exceptionally critical for these applications are particles that stick at the vacuum facing surfaces as well as desorption of water and hydrocarbons from the surfaces into the system, because this may interfere with the sensitive ultra‐high vacuum (UHV) and ultra‐clean vacuum (UCV) processes. In this contribution, some established cleaning methods and surface treatments are discussed with respect to their effect on reducing particle contamination and outgassing of water and organic compounds from stainless steel surfaces. It is clarified that the resulting cleanliness severely depends on the detailed steps during the surface treatment and subsequent cleaning. As a consequence, the discussed methods should be chosen and adapted with great care according to the specific demands of the final application area.     

Growth and characterization of hydroxyapatite nanorice on TiO2 nanofibers

Hydroxyapatite (HA) coating with nanoparticles like nanorice is fabricated on chemically pretreated titanium (Ti) surface, through an electrochemical deposition approach, for biomaterial applications. The Ti surface was chemically patterned with anatase TiO₂ nanofibers. These nanofibers were prepared by in situ oxidation of Ti foils in a concentrated solution of H₂O₂ and NaOH, followed by proton exchange and calcinations. Afterward, TiO₂ nanofibers on Ti substrate were coated with HA nanoparticles like nanorice. The obtained samples were annealed at high temperature to produce inter diffusion between TiO₂ and HA layers. The resultant layers were characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), X-ray Diffraction (XRD), Infrared Spectroscopy (FTIR), corrosion tests in SBF solution, and Electron Probe Micro Analysis (EPMA). It was found that only Ti from the titanium substrate diffuses into the HA coating and a good corrosion resistance in simulated body fluid was obtained.     

The Role of Oxidation in Blowing Particle‐Stabilised Aluminium Foams

Metal foams were produced by blowing gas into aluminium alloy melts. The effect of oxygen content of the blowing gas on composition and structure of the inner surface of the foam cells is studied by varying gas composition from argon, nitrogen and air to pure oxygen. Scanning Electron Microscopy, Auger Electron Spectroscopy and Transmission Electron Microscopy are used to analyse the surfaces. Initially particle‐free melts are pre‐treated by bubbling air through them after which a certain degree of foam stability is achieved. The oxidation products are characterised by microscopy on such foams.     

国产800级碳纤维表面状态及其复合材料界面性能EI北大核心CSCD

通过扫描电子显微镜（SEM）、原子力显微镜（AFM）、X射线光电子能谱（XPS）、复丝拉伸法、单丝拉伸法及单丝断裂法对3种国产800-12K碳纤维表面状态及其复丝拉伸性能、单丝复合体系的界面性能进行系统分析与研究。结果表明：3种国产800级碳纤维表面均较为光滑,纤维的粗糙度为9-17nm,纤维表面含氧量较高且稳定,O/C在0.23~0.27之间;3种国产800级碳纤维复丝拉伸强度相当,质量控制稳定,断裂伸长率为1.9左右,纤维与树脂基体匹配性较好;3种国产800级碳纤维单丝拉伸强度不稳定,纤维的表面化学活性对纤维与树脂基体的界面结合强度影响显著。     

Characterisation of the bioactive behaviour of sol–gel hydroxyapatite–CaO and hydroxyapatite–CaO–bioactive glass composites

The fabrication and characterization of sol–gel derived hydroxyapatite–calcium oxide (HAp–CaO) material is investigated focusing on the effect of the addition of a bioactive glass on the material bioactive behaviour through the fabrication of a novel HAp–CaO (70 wt.%)–bioactive glass (30 wt.%) composite material. The bioactive behaviour of the materials was assessed by immersion studies in Simulated Body Fluid (SBF) and the alterations of the materials surfaces after soaking periods in SBF were characterized by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). A brittle and weakly crystalline carbonate hydroxyapatite (HCAp) layer was found to develop on the surface of all samples, few hours after immersion in SBF, confirming the high bioactivity of the material. Alterations of the morphology of the developed HCAp layer, which led to a more compact structure, were observed on the surface of composite samples after 7 days of immersion in SBF. The presence of the CaO phase seems to accelerate the formation of HCAp, while the bioactive glass affects both the morphology and cohesion of the developed layer.     

Surface modifications of a vulcanized rubber using corona discharge and ultraviolet radiation treatments

Two different surface treatments have been applied to a synthetic vulcanized styrene-butadiene rubber (R1): corona discharge and UV treatment. Corona discharge treatment has been carried out on R1 rubber by varying the electrode-sample distance (2–4 mm), the duration (1 to 11 sec) and several parameters in the treatment of R1 rubber with UV treatment (lamp-sample distance between 1 and 5 cm, the duration between 30 sec and 5 min). The effects on both treatments on the surface of R1 were analyzed using contact angle measurements, ATR-IR spectroscopy, Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM). A noticeable decrease in contact angles was observed on the R1 rubber by applying both treatments, although the modifications produced on the rubber surface were different. Corona discharge mainly affected the morphology of the R1 rubber surface whereas UV treatment mainly modified its chemistry. The migration of zinc stearate was only produced by UV treatment but not with corona discharge. Therefore, the UV treatment of R1 rubber was more aggressive, facilitating the migration of moieties from the bulk to the surface and producing oxygen moieties.     

Surface-driven porphyrin self-assembly on pre-activated Si substrates

Self-assembled molecular thin films of melamine-bridged bis-porphyrin dyad, both in free form, P(H2)P(H2), or as Zn(II) metallated complex, P(Zn)P(Zn), were deposited on crystalline Si(100) by soaking or drop-casting techniques. The influence of the adopted preparation methodology, the substrate surface pre-activation procedure and the used solvent (THF or CHCl3) on the morphology and surface coverage of the resulting films was investigated by FE-SEM (Field Emission-Scanning Electron Microscopy) and AFM (Atomic Force Microscopy). The chemical composition and electronic structure of the most promising systems were also addressed by XPS (X-ray Photoelectron Spectroscopy). The results pointed out that an accurate tuning of porphyrin-porphyrin, porphyrin-substrate and porphyrin-solvent molecular interactions allow to tailor the morphogenesis and chemico-physical properties of the final self-assembled films. In addition, preliminary gas sensing tests evidenced the potential of the present porphyrin-based films for the development of new molecular sensing devices.     

Modifizierung der Gasabgabe von Edelstahloberflächen durch Ionenimplantation

Several years ago there were established a new ion-implantation technique, the so called Plasma source ion-implantation. This technique was applied on stainless steel samples to implant ions of nitrogen or oxygen into the surface in a controlled manner and to create barrier layers of nitrides or oxides, respectively. With the help of surface-analytical methods it could be shown that oxygen or nitrogen were incorporated homogeneously in a certain depth region below the outermost surface. Some measurements of the outgassing behavior of these plasma treated surfaces will be shown. The results are discussed as originated from the surface modification by the plasma treatment and the creation of the implantation layer.     

氢,氦共注入的硅样品的退火行为

在以氢先氦后的顺序注入的硅样品中，经不同温度的退火，发现比氢、氦分别单独注入时小得多的注入剂量足以使硅样品表面产生砂眼及了。本文用ＲＢＳ／Ｃ、Ｘ射线罩是衍射、ＡＦＭ、ＸＴＥＭ等不同方法对氢、氦共注入样品进行了研究，对结果作了计算机模拟，并对其机制做了分析与研究。