Optical Properties of Sol-Gel Coatings on Plastic Foils Embossed with Surface-Relief Gratings

A novel technique has been developed to fabricate surface-relief gratings using sol-gel derived porous coating on plastic foil substrates. Organically modified TiO₂ sol was prepared by roll-coating on OPP foil substrates. The plastic films coated with TiO₂ nano-particles were embossed to form surface-relief gratings with micro-structures. The morphology of the porous coatings and the micro-structures were investigated using electron scanning microscopy (SEM). Optical transmission of the films was measured using UV-VIS and IR spectroscopy. The diffraction efficiency of the gratings on the coated plastic foil was examined in terms of fabrication conditions. It was shown that special figures could be seen in the films when the angle of view was changed. The final products of the composite films are transparent and suitable for industry manufacture and applications.     

聚合物光盘基板材料

光盘是一种以非接触方式记录/再现信息的信息记录介质,主要由基板、记录层和保护层组成.其中,基板材料所用的光学塑料是光盘生产的主要原材料,对光盘的性能和成本构成至关重要.本文综述了聚合物光盘基板材料的研究现状及其发展趋势.光盘基板材料主要包括传统的聚碳酸酯(PC)、聚甲基丙烯酸甲酯(PMMA)、环氧树脂以及近年发展起来的非晶环烯烃聚合物.研制具有较低的双折射、吸湿性、固化成型收缩率以及较高的存储密度和存储寿命的光盘基板材料是聚合物光盘基板材料的一个重要研究领域.     

Formation of Anatase Nanocrystals-Precipitated Silica Coatings on Plastic Substrates by the Sol-Gel Process with Hot Water Treatment

Anatase nanocrystals-precipitated silica coatings were formed on plastic substrates such as poly(ethylene terephtalate) (PET), acrylic resin (AC) and polycarbonate (PC) from silica-titania gel coatings with and without addition of poly(ethylene glycol) (PEG) by hot water treatment. The maximum thickness of the coatings which can be formed without cracking or peeling-off was 100 to 200 nm for PET and PC substrates, whereas it was less than 50 nm for AC substrates. After a hot water treatment at 90°C for 120 min, the size of the anatase nanocrystals increased to be 30 and 50 nm for the coatings obtained with and without PEG, respectively. Anatase nanocrystals were formed throughout the whole of the coatings obtained with PEG and were formed only on the surface of the coatings obtained without PEG. Both coatings obtained with and without PEG were highly transparent. The plastic substrates with coatings obtained without PEG showed good weathering resistance owing to the protective effects of the residual silica under-layer. The coatings obtained with PEG showed higher photocatalytic activities than those obtained without PEG due to smaller size and higher dispersion of anatase nanocrystals in the coatings.     

多模梯度（聚焦）型塑料光纤研究进展

多模梯度型塑料光纤，其折光 率径向分布呈连续的抛物线型分布。光在这种纤维中的行程按正弦波前进。这类纤维具有频带宽、传输容量大，信号保真度高的优点。本文就二十多年来有关ＧＩＰＯＦ的研究进展进行了较全面的综述。     

Wet Coating Deposition of ITO Coatings on Plastic Substrates

In₂O₃:Sn (ITO) transparent conducting coatings of high optical quality have been obtained on glass and several plastic substrates by spin and dip coating processes followed by a low temperature processing (T < 130°C). The sols are made of crystalline nanoparticles redispersable in an alcohol and modified by adding a binder to favour the coalescing of the particles and to allow the deposition of thick single layers (>400 nm). The smallest stable resistivity so far obtained is = 9 × 10^–2cm (sheet resistance of 1.6 k for a 570 nm thick single layer). The transparency in the visible range is high, T 87%, the abrasion resistance is in agreement with DIN 58-196-G10 and the hardness according to ASTM D 3363-92a is 1H. A spray process allows to obtain antiglare-conducting coatings with an adjustable gloss of 60 to 80 GU and an optical resolution >8 lines/mm.     

Organopolysiloxanes as Chemically Sensitive Coatings for Optical Fibers

Various types of UV-curable organically modified siloxanes have been synthesized by the sol-gel method with the aim of fabricating chemically sensitive coatings for silica optical fibers. The refractive index of the coating material can be tailored in the range from 1.46 to 1.56 and sensitivity towards CO2 is achieved by incorporation of amino groups. The interaction of the cured layers with CO2 or with hydrocarbons has been studied in immersion experiments. Both the reaction of CO2 with incorporated amino groups and the penetration of hydrocarbons into the layer induce changes of the light absorption coefficient and the refractive index of the coating which are detected by measuring the output light intensity from the fiber.     

Photocatalytic TiO2 Coatings: Effect of Substrate and Template

Transparent TiO₂ films with a high photodegradation activity towards an azo dye in aqueous solution were prepared by sol–gel processing. Films on soda–lime glass supports protected with a thin silica barrier layer exhibited better crystallization and monodisperse nanoparticles, higher absorption of light below 370 nm, and higher photocatalytic activity than those films deposited on bare glass supports proving the detrimental effect of interdiffused sodium ions on the development of the anatase nanostructure. The effect of substrate was more pronounced in thinner films (300 nm) than in thicker ones (1200 nm), which were achieved by adding a template (i.e. Pluronic F127) to the sol.     

Anti-Reflective Coatings for CRTs by Sol-Gel Process

Two types of anti-reflective coatings composed of nano-particles were developed for cathode ray tubes (CRTs). The anti-reflective and anti-static coating is composed of two layers. An outer SiO₂ layer is formed over a porous inner layer composed of titanium oxynitride (TiO _x N_y), antimony-doped tin oxide (ATO) and SiO₂. To control the reflection of the film, a porous structure is formed using a mixed sol composed of TiO _x N _y -ATO particles and hydrolyzed-polymerized tetraethoxy-silane (TEOS). The resulting double layered coating is shown to consist in a nanocomposite pseudo three-layer structure. The antireflective electromagnetic-wave-shielding coating is also composed of two layers. An outer SiO₂ layer is formed over an electric-conductive inner layer composed of silver colloids, TiO _x N _y nano particles. Silver colloids are used to obtain a film having low surface resistivity and TiO _x N _y nano-particles contained in the inner layer enhance the durability of the film. To reduce the plasma-resonance absorption caused by silver colloids, silver ions are added to the outer layer solution. The silver ions diffuse into the inner layer from the outer layer when the film is cured, touch to the surface of silver colloids, suppress the silver colloid growth and reduce the specific absorption of the film. These coatings are successfully applied to the panel glass for CRTs on an industrial scale.     

Anti-Reflective Coatings for CRTs by Sol-Gel Process

Anti-reflective and electromagnetic shielding double-layered coatings were developed for cathode ray tubes (CRTs) by wet chemical process. An outer SiO₂ layer is formed over a porous inner tin-doped indium oxide (ITO) particle layer. ITO particles used in the inner layer lower the sheet resistance below 10³ohm/sq. and an electromagnetic shielding property is attained. To improve the abrasion wear resistance of the film, the structure of the film and hydrolysis-polymerization condition of tetraethoxy-silane (TEOS) are estimated. An outer SiO₂ layer component penetrates into the inner layer and adheres to the glass surface. As the extent of hydrolysis of TEOS proceeds and the molecular weight of hydrolyzed TEOS becomes small, the abrasion wear resistance of the film enhances. The relation between the curing condition of the film and surface resistance of the film is investigated. The surface resistance of the film lowers by curing the film in reductive atmosphere. The transmittance of the film in the near-infrared region shows that the lowering of surface resistance of the film is caused by the increase of carrier concentration of ITO particles. The double layered coatings are successfully applied to the panel glass for CRTs on an industrial-scale.     

电沉积磷酸钙生物活性陶瓷

在医用合金Ti6A14V基底上研究了电流密度、阴极电位和电解液温度等实验条件对磷酸钙生物陶瓷电沉积层的组成、结构和表面形貌等特性的影响，用扫描电子显微镜（SEM）、X射线衍射（XRD）、傅立叶变换红外光谱（FTIR）和感耦等离子体原子发射光谱（ICP／AES）等技术对磷酸钙陶瓷沉积层进行了表征．依据各种用酸钙盐的热力学性质，采用低温城液后处理的方法将前驱体转化为均匀单一的多孔状纯羟基历灰石沉积层．     

Optical Multiplexed Bioassays for Improved Biomedical Diagnostics

Conventional analytical methods based on the detection of a single disease marker may not be sufficiently accurate because the progression of disease generally involves multiple chemicals and biomolecules. The drive for simultaneous analysis of multiple targets, which plays a key role in both basic biomedical research and clinical applications, demands the development of multiplexed bioassays with high‐throughput. In this minireview, we summarize the recent progress in optical multiplexed analytical techniques for improving biomedical diagnostics, in which fluorescence and surface enhanced Raman scattering (SERS) with distinctive optical features are chosen as the main readout signals. Focusing on multiplexed strategies in the biomedical field, a selection of recent contributions from biosensing of multiple analytes and multicolor cellular tracking to in vivo multiplexed bioimaging are highlighted. Finally, we frame the future challenges and opportunities for multiplexed bioanalysis.     

A Novel Method for Synthesis of ZSM‐5 Coatings on Monolithic Cordierite Substrate

ZSM‐5 coatings, have been synthesized onto a monolithic cordierite substrate by an environmental friendly and high coating selectivity method—Vapor Phase Transport (VPT). With this method, an aluminosilicate gel coated onto the monolithic cordierite substrate has been transformed into a ZSM‐5 layer under vapors of n‐butylamine and water, n‐Butylamine played a key role in the forming of ZSM‐5 layer on the cordierite substrate. The ZSM‐5/cordierite monolith composites prepared by this method were ion‐exchanged with Cu²⁺ and tested for the selective catalytic reduction of NO by propane. The deNO_x activities of Cu/ZSM‐5 monolith catalysts were not only dependent on the ion‐exchange methods, but also on the ZSM‐5 loading of the monolith catalysts. The best result was obtained over the Cu (B3)/ZSM‐5 monolith catalyst, which had a ZSM‐5 loading of about 13% and was prepared by a pressure exchange procedure. At a temperature of 723 K and a space velocity of 10,000 h^?1 (based on the monolith volume), 85% of NO conversion and 93% of C₃H₃ conversion were achieved over the Cu(B3)/ZSM‐5 monolith catalyst.     

A Novel Continuous Industrial Process for Producing Hydroxyapatite Nanoparticles

Fluidinova, a recent start‐up high technology engineering company, has developed and is now commercializing a novel continuous industrial reactor NETmix for the manufacture of high added value products, such as nanomaterials, microemulsions, and pharmaceutical products. Through this technology, Fluidinova, in cooperation with Instituto de Engenharia Biomédica, has developed and patented the industrial process for the synthesis of a new high quality product consisting of hydroxyapatite nanoparticles with extremely high purity and crystallinity to be used as biocompatible nanomaterial for biomedical and pharmaceutical applications, to improve the quality of the already existing hydroxyapatite based medical devices, such as bone grafts, coated implants, and drug delivery systems.     

聚合物光盘基板材料的研究进展

光盘是一种以非接触方式记录/再现信息的信息记录介质,主要由基板、记录层和保护层组成。其中,基板材料所用的光学塑料是光盘生产的主要原材料,对光盘的性能和成本构成至关重要。本文综述了聚合物光盘基板材料的研究现状及其发展趋势。光盘基板材料主要包括传统的聚碳酸酯（PC）,聚甲基丙烯酸甲酯（PMMA）、环氧树脂以及近年发展起来的非晶环烯烃聚合物。研制具有较低的双折射、吸湿性、固化成型收缩率以及较高的存储密度和存储寿命的光盘基板材料是聚合物光盘基板材料的一个重要研究领域。     

Investigation of Phase Transformations in the Synthesis of Catalytic Coatings on Metal Substrate

Catalytic coatings based on the Ni–Al–Al(OH)₃ system with the addition of metal hydroxides Mg(OH)₂ and Ca(OH)₂ are obtained by the method of cold gas dynamic spraying. The TGA/DSC curves were constructed and analyzed. The optimal temperature for thermal treatment at 750°C was chosen, at which in the coating the complete decomposition of hydroxides into metal oxides is provided, which is confirmed by the results of chemical and phase analysis. It was established that the thermal treatment has a positive effect on the specific surface of the coating increasing it by 3.5 times.     

Exceptionally Plastic/Elastic Organic Crystals of a Naphthalidenimine-Boron Complex Show Flexible Optical Waveguide Properties

The design of molecular compounds that exhibit flexibility is an emerging area of research. Although a fair amount of success has been achieved in the design of plastic or elastic crystals, realizing multidimensional plastic and elastic bending remains challenging. We report herein a naphthalidenimine–boron complex that showed size-dependent dual mechanical bending behavior whereas its parent Schiff base was brittle. Detailed crystallographic and spectroscopic analysis revealed the importance of boron in imparting the interesting mechanical properties. Furthermore, the luminescence of the molecule was turned-on subsequent to boron complexation, thereby allowing it to be explored for multimode optical waveguide applications. Our in-depth study of the size-dependent plastic and elastic bending of the crystals thus provides important insights in molecular engineering and could act as a platform for the development of future smart flexible materials for optoelectronic applications.     

Optical Fiber Chemiluminescence Biosensor for Antioxidants Based on an Immobilized Luminol/Hematin Reagent Phase

ABSTRACT

A chemiluminescence (CL) biosensing system for antioxidants was developed based on luminol and hematin co-immobilized on a cellulose membrane disc. The concentration of the antioxidant was quantified through the measurement of the inhibition of the CL emitted when hydrogen peroxide was introduced into the reagent phase. The instrumentation employed in the measurement was a fabricated luminometer employing optical fibers and a UV-enhanced photodiode transducer. Under optimum conditions, linear calibration curves were obtained for antioxidant concentrations ranging from 1 × 10^-4 M to 0.10 M, with an average relative standard deviation of about 5%. The minimum detectable concentration was 100 μM, and the response time was less than 60 seconds. The sensor response correlated well (r = 0.9979) with the results of a standard colorimetric method for a specific antioxidant (propyl gallate). The sensor was used to assess the antioxidant capacity of water infusions prepared from the dried leaves of some Philippine medicinal plants.     

Improved Process for the Preparation of Tamsulosin Hydrochloride

Ellman's sulfinamide reagent is used in asymmetric synthesis of Tamsulosin hydrochloride. The enantiomeric ratio achieved is 87:13. The crystallization of the same with dibenzoyl tartarate afforded the product 2 with >99.5% ee.