Oberflächenfunktionalisierung von Kunststoffoptik

Surface Functionalization of Polymer Optics Transparent plastics have been used for optical applications with growing demand. This development is accompanied by a desire for extended surface functionalities like antireflection and hardening. Coating processes well established for glass optics cannot be applied in most cases. A manifold of polymer materials with different chemical surface states require special coating deposition parameters. In the first part of the tutorial the main plastic materials are introduced and their properties which are important for the vacuum deposition processes will be discussed.     

PVD‐Schutzschichten für Werkzeuge des Präzisionsblankpressens

PVD protective coatings for precision molding tools Precision glass molding (PGM) is a replicative hot forming process for the production of complex optical components, such as aspherical lenses for digital and mobile phone cameras or optical elements for laser systems. The efficiency and thus also the profitability of the PGM depend on the unit price per pressed component, which correlates primarily with the service lifetime of the pressing tools. To increase tool lifetime, the tool surfaces are coated with protective coatings based on precious metals or carbon using physical vapour deposition (PVD). The PVD coating technology enables the deposition of thin coatings, which also follow more complex surface geometries and achieve a high surface quality. PVD coatings are also commonly used to protect tools from wear and corrosion. This paper presents two chromium‐based nitride hard coatings produced by an industrial PVD unit and investigated for their applicability for PGM. Two different coating architectures were implemented, on the one hand a single coating chromium aluminium nitride (Cr,Al)N coating and on the other hand a nanolaminar CrN/AlN coating with alternating layers of chromium nitride and aluminium nitride. The latter is a coating consisting of hundreds of nano‐layers, only a few nanometers thick. Both coatings, (Cr,Al)N and CrN/AlN, each have a thickness of s ～ 300 nm in order to follow the tool contour as closely as possible. The properties of the coating systems, which are of particular relevance for PGM, are considered. These include on the one hand the adhesion of glass, the roughness and topography of the surface and the adhesion between the coating and the tool material. In addition, the barrier effect of the coatings against diffusion of oxygen was investigated. In order to reproduce the thermal boundary conditions of the PGM, thermocyclic aging tests are performed and their influence on the different properties is described.     

机械镀锌沉积机理的研究

通过蒸发皿模拟试验和生产试验,采用体视显微镜观察了机械镀锌形层过程中金属锌粉在预镀工件表面的吸附、沉积过程,并用光学相机记录了金属锌粉的沉积过程.运用物理化学、电化学的基础理论分析了金属锌粉的沉积机理.分析结果表明,基层建立阶段,金属锌粉和Sn2+发生化学反应;镀层增厚阶段,金属锌粉和M2+发生化学反应;金属锌粉表面化学反应造成的库仑引力和机械镀锌过程玻璃珠冲击介质的碰撞是锌粉沉积的主要原因.     

MANUFACTURE OF OPTICAL WAVEGUIDES USING AEROSOLS: A REVIEW

Optical waveguides are glass filaments used to transmit light for telecommunication and other uses. To achieve high performance, inexpensive optical communication systems require: glass of exceptional purity and precise control of glass refractive index. For this reason, aerosol deposition is utilized exclusively for the manufacture of optical waveguides. The applications and operation of optical waveguides are outlined in this paper. The major manufacturing processes are discussed, with emphasis on aerosol formation and deposition.     

Plasmaunterstütztes Aufdampfverfahren eröffnet neue Perspektiven in der Brillen- und Feinoptik

Plasma-ion assisted deposition, a newly developed evaporation technique for the production of optical coatings results, in outstanding film properties even at a low substrate temperature. The results of single layer investigations in comparison with conventional evaporation demonstrate the physical effects that improve the film properties. The combination of hard- and anti reflexion coating in one vacuum process for plastic eye glass lenses reduces the production time drastically while the quality of the finished product is secured. The production of ultra stable interference filters for fiber optic communication applications demonstrates the superior ability of this technology.     

MANUFACTURE OF OPTICAL WAVEGUIDES USING AEROSOLS: A REVIEW

ABSTRACT

Optical waveguides are glass filaments used to transmit light for telecommunication and other uses. To achieve high performance, inexpensive optical communication systems require: glass of exceptional purity and precise control of glass refractive index. For this reason, aerosol deposition is utilized exclusively for the manufacture of optical waveguides. The applications and operation of optical waveguides are outlined in this paper. The major manufacturing processes are discussed, with emphasis on aerosol formation and deposition.     

Vakuumbeschichtung von PET‐Folie mit Solar‐Control‐Schichten

Solar control coatings as an integrated part of automotive glass are increasingly used in a growing number of car models of all classes of the European car manufactures. The advantages of that solar control laminated glass are an increased reflection in the near infrared spectral region, which results in a reduction of heat gain of about 50 % in the cabin caused by solar radiation, an increase of passenger comfort and the safe of fuel for air conditioning. One process for the production of solar control coatings is the magnetron sputtering onto optical grade flexible PET‐film. The performance of these coatings as well as technological issues of the deposition process are presented.     

Optische in‐situ Prozessverfolgung und ‐steuerung

In situ optical monitoring and process control: Measuring transmittance and reflectance of optical coatings during deposition Optical monitoring techniques havebecome indispensable parts of deterministic preparation strategies for sophisticated optical coatings. Traditional versions of optical broadband monitoring are based on measurements of the transmission spectrum or alternatively the reflection spectrum of the growing film. In the case of practically loss‐free samples, both approaches principally deliver equivalent information. In the case of absorbing coatings, the information gained from the different spectra may be no more equivalent. Instead, it may be reasonable to record both spectra simultaneously, in order to get a more complete picture of the status of the growing film. We present a corresponding measurement setup designed for use in typical coating evaporation processes and demonstrate its application to the deposition of alumina coatings as well as aluminum mirrors.     

Transparente und leitfähige Veredelung von Kunststoffoberflächen

Deposition Techniques for Transparent Conducting Thin‐Films on Glass and Polymer Substrates We report on thin films deposited at atmospheric pressures on glass and polymer substrates with various techniques. The introduced thin‐film materials show intrinsic properties being suitable for different applications while maintaining the principle properties of the substrates themselves (e. g. shape. rigidity/flexibility, transparency). With the main focus on optical and electronic applications the properties of the deposited films can be adjusted by the choice of coating material (e. g. metal oxide, CNT), the film's shape (compact, particulate) and the deposition process itself. We compare deposition and properties of different TCO‐materials with CNT‐based thin film techniques and demonstrate approaches for the integration of these processes in production lines.     

等离子体发射监控系统参与的中频孪生反应磁控溅射沉积TiO_2薄膜的实验研究

在一个孪生靶实验装置上进行了中频反应磁控溅射沉积TiO_2薄膜的工艺实验.得到了一组真实的反应溅射TiO_2薄膜的沉积速率和真空与反应气体流量之间关系的迟滞曲线(无等离子体发射监控系统Plasma Emission Monitoring,PEM)参与.介绍了PEM参与下的反应溅射TiO_2的一些实验现象和结果,此时TiO_2的沉积速率与PEM设定值呈很好的线性关系,反应溅射可以稳定在过渡态的任一工作点.设定值是PEM控制系统最关键的参数,直接决定着控制的可靠性、反应溅射速率以及薄膜的微观结构.结果表明,为了得到标准化学配比的反应物,PEM的设定值不能超过某个极限值.要在保证化学配比也就是反应物的成分或结构的前提下提高沉积速率才有意义.     

PEM控制中频反应磁控溅射制备TiO_2薄膜的研究

采用中频反应磁控溅射孪生靶在玻璃基体上沉积TiO2薄膜。沉积过程中采用多路送气和等离子体发射光谱监测控制系统,使整个反应溅射过程维持在过渡区,从而快速稳定获得均匀高质量的TiO2薄膜,沉积速度在50 nm/min以上。随着SP值的增加,沉积速率的增加呈线性关系。通过比较不同SP值制备的TiO2薄膜的光谱图发现,快速稳定地沉积TiO2薄膜的SP值大致在2.5~3.8范围内。     

Transluzente oxidfaserverstärkte Glasmatrix‐Verbundwerkstoffe

Translucent oxide fiber reinforced glasmatrix composites The aim of the work is the developement of transparent glass matrix composites. Therefore besides the mechanical properties also the optical properties of the components have to be adapted. In this study the influence of different fiber coatings (boron nitride, titanium oxide and a boron nitride/titanium oxide double coating) on the mechanical and optical properties of Nextel 440‐fiber reinforced glass was investigated. Micromechanical investigations (push‐in‐tests) and 3‐point‐bending tests have shown the best improvement of the fracture toughness for the binary boron nitride/titanium oxide coating. For single coatings of boron nitride or titanium oxide the transparency was characterized by the transmission spectra.     

Beidseitige Innen‐ und Außenbeschichtung von PET‐Getränkeflaschen

Double‐sided interior and exterior coating of PET beverage bottles Plasma‐enhanced methods for the interior coating of PET beverage bottles have already been put into practice in the industry. Thereby the achieved barrier properties are limited due to defects in the coating, which emerge during the layer growth and allow a higher permeability. One possible way to improve barrier properties is the double‐sided coating. The implementation of the concept in form of a demonstrator plant is presented. By means of optical emission spectroscopy (OES) as a very versatile and easy to use method for the surveillance of industrial plasma processes, the influence of the gas composition on the plasma homogeneity and barrier properties of the coating is demonstrated. Permeation measurements are carried out, showing the potential of the combined coating process for the deposition of effective coatings.     

Antireflection coatings on plastics deposited by plasma polymerization process

Antireflection coatings (ARCs) are deposited on the surfaces of optical elements like spectacle lenses to increase light transmission and improve their performance. In the ophthalmic industry, plastic lenses are rapidly displacing glass lenses due to several advantageous features. However, the deposition of ARCs on plastic lenses is a challenging task, because the plastic surface needs treatment for adhesion improvement and surface hardening before depositing the ARC. This surface treatment is usually done in a multi-stage process—exposure to energetic radiations, followed by deposition of a carbonyl hard coating by spin or dip coating processes, UV curing, etc. However, this treatment can also be done by plasma processes. Moreover, the plasma polymerization process allows deposition of optical films at room temperature, essential for plastics. The energetic ions in plasma processes provide similar effects as in ion assisted physical deposition processes to produce hard coatings, without requiring sophisticated ion sources. The plasma polymerization process is more economical than ion-assisted physical vapour deposition processes as regards equipment and source materials and is more cost-effective, enabling the surface treatment and deposition of the ARC in the same deposition system in a single run by varying the system parameters at each step. Since published results of the plasma polymerization processes developed abroad are rather sketchy and the techniques are mostly veiled in commercial secrecy, innovative and indigenous plasma-based techniques have been developed in this work for depositing the complete ARCs on plastic substrates.     

Gießformherstellung durch Beschichtung von Modellen

Casting molds, produced by coating of prototypes A new method for the cost effective production of forming tools is introduced. These tools can be used for the production of prototypes and small series of products. The new method for the production of moulds and injection moulding tools consists of the following steps: ?coating of a positive model with a hard coating by physical vapour deposition (PVD)‐technologies ?deposition of a support coating, consisting of a metal coating, applied by an atmospheric plasma spraying technology ?embedding in a polymer removing of the positive model ?completion of the tool by adding the moulding equipment By using such a tool it is possible to produce more than 1000 parts of a polymer (enforced by glass fibre) or more than 1500 parts of a regular polymer.     

Polyelectrolyte multilayers coating for organic solvent resistant microfluidic chips

The layer-by-layer (LbL) deposition technique was used to coat and protect poly(methyl methacrylate) (PMMA) and poly(dimethylsiloxane) (PDMS) substrate from organic solvent. PMMA and PDMS substrates were protected by polyelectrolyte multilayers (PEM) thin films of either poly(diallydimethiyl ammonium chloride) and Poly(styrene sulfonate) PDADMAC/PSS or chitosan/alginate. The PEM depositited on the PMMA and PDMS substrates improved the organic solvent resistance with the best results obtained from the chitosan/alginate over the PDADMAC/PSS pair. The more hydrophilic character of the chitosan/alginate and the PDADMAC/PSS film caused a significant decreasing rate of organic solvent pentration into the PMMA substrate which retain transparent optical properties for up to 30 dipping in acetonitrile. A 20 layers chitosan alginate film also decreased PDMS substrate swelling when exposed to chloroform vapor. The PEMs coating could protect the PMMA and PDMS sample against organic solvent and vapor which could make them useful in microfluidic systems even in agressive environment.     

Graphite-coated nanoelectrospray emitter for mass spectrometry

A new, more rapid method for coating nanoelectrospray emitters with graphite is to use a vacuum deposition chamber and a graphite carbon electrode. This method allows for mass production of nanoelectrospray emitters in a short period of time. The emitters are laser-pulled borosilicate glass micropipets and have tapers of around 4 microm i.d. The conductive coating applied to the emitter is only 20-30 nm thick, allowing for optical transparency with the borosilicate emitters. The conductive coating is stable for a number of hours at the high voltages used for nanoelectrospray ionization and is durable in both positive and negative ion modes-even during electrical discharge. This stability will make it possible to couple these emitters with online separations such as capillary liquid chromatography or capillary electrophoresis.     

Chiral separations using polymeric surfactants and polyelectrolyte multilayers in open-tubular capillary electrochromatography

In this study, fused-silica capillaries are modified using a polyelectrolyte multilayer (PEM) coating procedure in open-tubular capillary electrochromatography. The PEM coating was constructed in situ with alternating rinses of positively and negatively charged polymers. The quaternary ammonium salt poly (diallyldimethylammonium chloride) was used as the cationic polymer, and the polymeric surfactant poly (sodium N-undecanoyl-l-leucylvalinate) was used as the anionic polymer. Previous studies have shown that the PEM-coated capillaries used for achiral separations have excellent reproducibilities and high stabilities against extreme pH values. In the current study, this PEM coating approach was applied to chiral separations of 1,1'-binaphthyl-2,2'-dihydrogenphosphate (BNP), 1,1'-bi-2-naphthol, secobarbital, pentobarbital, and temazepam. However, the PEM coating procedure used in the achiral studies needed to be significantly modified in order to achieve chiral separations. Optimal conditions were established by varying the additives (sodium chloride, 1-ethyl-3-methyl-1H-imidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium tetrafluoroborate) in the polymer deposition solutions, the salt concentration, the column temperature, and the bilayer number. Reproducibilities were evaluated by use of the relative standard deviation (RSD) values of the electroosmotic flow (EOF) and the first peak ((R)-(+)-BNP). In all cases, the run-to-run and capillary-to-capillary RSD values of EOF were less than 0.5%, and the run-to-run RSD values of the (R)-(+)-BNP peak were less than 1%. In addition, more than 230 runs were performed on a single PEM-coated capillary.     

In‐situ Messung dünner Schichten auf Architekturglas

For the deposition of modern coatings on architectural glass (energy‐saving, solar control, anti‐reflective), reactive magnetron sputtering plays an outstanding role. The production of these coatings by reactive sputtering requires a manufactoring equipment, that ensures high quality as well as efficient deposition of the coatings. Thin film measurement by in‐situ ellipsometry can very impressively used for monitoring and controlling the film properties, in particular in the case of more complex coatings. With regard to long‐term stability the in‐situ film measurement is of special importance with respect to the use of the novel mid‐frequency magnetron sputter technique. This technique allows the deposition rate to be increased up to 500 %, however, a dynamical plasma stabilization in the so called »transition mode« is necessary. Within the framework of a project supported by the BMBF, the spectroscopic ellipsometry was implemented on a large scale glass deposition plant (Semco Glasbeschichtung, Neubrandenburg) and was tested during the production. The investigations show that ellipsometry is outstandingly suitable for an accurate determination of the optical layer properties of coatings on architecture glass, even for complex layer systems. Therefore, the basis for an improvement of the efficiency of the plant is given.     

High-aperture optical waveguides based on fluorine-doped silica glass

The dependence of fluorine incorporation into silica glass on conditions of the optical waveguide blank manufacture using the method of modified chemical vapor deposition (MCVD) is studied. The degree of fluorine incorporation at constant consumption of a fluoridizer (SiF₄) is shown to increase with an increase in the volume of deposited material. Samples of multimode optical waveguides with a core from pure silica glass and a reflective coating made of fluorine-doped silica glass with a numerical aperture of ∼0.18 are obtained. Optical losses in such optical waveguides reach 0.5 dB/km in the long-wavelength region of the spectrum. Original Russian Text ? A.N. Guryanov, M.Yu. Salganskii, V.F. Khopin, A.F. Kosolapov, S.L. Semenov, 2009, published in Neorganicheskie Materialy, 2009, Vol. 45, No. 7, pp. 887–891.