Large Size Recyclable Colored Glass Plates Prepared from Organic Colorant Dispersed Silica Sols by the Dipping Method

We have prepared the recyclable colored glass plates of blue, green, or red by coating organic colorant dispersed silica sols. Phthalocyanine-type or diketopyrrolopyrrole-type compounds were used as colorants for colored coating and the sol coated glass plates were heat-treated at 300–400°C. The coating was done by using a dipping-withdrawing equipment designed originally for coating large sized glass plates with 2 m in length and 1 m in width. The colored coating films were uniform and transparent with low haze values less than 1.0% and with thickness of 120–540 nm. The visible light transmittance of the colored glass plates was controlled in the relatively wide range of 50–90% by changing the film thickness or the colorant concentration in the coating sols. The practical durabilities of the blue colored glass plate against abrasion, scratch, chemicals and UV-light were acceptable to the specification required for interior glass products.     

Enhanced electrochromics of nanoporous cobalt oxide thin film prepared by a facile chemical bath deposition

A highly porous cobalt oxide thin film was prepared on ITO glass by a facile chemical bath deposition (CBD) method. The as-prepared cobalt oxide film has an intercrossing net-like morphology. The electrochromic performance of cobalt oxide film was investigated in 0.1 M KOH by means of transmittance, cyclic voltammetry (CV) and chronoamperometry (CA) measurements. The cobalt oxide thin film exhibits a noticeable electrochromism with reversible color changes from pale yellow to dark grey and presents a transmittance variation with 36% in the visible range. The porous cobalt oxide thin film also shows good reaction kinetics with fast switching speed, and the coloration and bleaching time are 2.5 and 2 s, respectively.     

Layer-by-layer fabrication of broad-band superhydrophobic antireflection coatings in near-infrared region

Broad-band superhydrophobic antireflective (AR) coatings in near infrared (NIR) region were readily fabricated on silicon or quartz substrates by a layer-by-layer (LbL) assembly technique. First, a porous poly(diallyldimethylammonium chloride) (PDDA)/SiO2 nanoparticle multilayer coating with AR property was prepared by LbL deposition of PDDA and 200 nm SiO2 nanoparticles. PDDA was then alternately assembled with sodium silicate on the PDDA/SiO2 nanoparticle coating to prepare a two-level hierarchical surface. Superhydrophobic AR coating with a water contact angle of 154 degrees was finally obtained after chemical vapor deposition of a layer of fluoroalkylsilane on the hierarchical surface. Quartz substrate with the as-fabricated superhydrophobic AR coating has a maximal transmittance above 98% of incidence light in the NIR region, which is increased by five percent compared with bare quartz substrate. Simultaneously, the superhydrophobic property endows the AR coating with water-repellent ability. Such superhydrophobic AR coatings can effectively avoid the disturbance of water vapor on their AR property and are expected to be applicable under humid environments.     

Layer-by-layer assembled films of cellulose nanowires with antireflective properties

Natural nanowires (NWs) of cellulose obtained from a marine animal tunicate display surprisingly high uniformity and aspect ratio comparable with synthetic NWs. Their layer-by-layer assembled (LBL) films show strong antireflection (AR) properties having an origin in a novel highly porous architecture reminiscent of a "flattened matchsticks pile", with film-thickness-dependent porosity and optical properties created by randomly oriented and overlapping NWs. At an optimum number of LBL deposition cycles, light transmittance reaches nearly 100% (lambda approximately 400 nm) when deposited on a microscope glass slide and the refractive index is approximately 1.28 at lambda = 532 nm. In accordance with AR theory, the transmittance maximum red-shifts and begins to decrease after reaching the maximum with increasing film thickness as a result of increased light scattering. This first example of LBL layers of cellulose NWs can be seen as an exemplary structure for any rigid axial nanocolloids, for which, given the refractive index match, AR properties are expected to be a common property. Unique mechanical properties of the tunicate NWs are also a great asset for optical coatings.     

碱/酸两步催化法制备耐候性SiO2增透膜的研究

以正硅酸乙酯(TEOS)为先驱体,采用碱/酸两步催化溶胶-凝胶法制备出一种兼具碱催化增透膜的高透过率和酸催化增透膜的良好耐摩擦性能的优点的SiO2增透膜。对酸碱催化SiO2相对比例及酸催化时水含量的系统研究表明,当酸催化SiO2的含量为50%时,增透膜综合性能最好,即具有高透过率和高耐摩擦性;当nH2O/nHCl=1∶0.0010时,增透膜的透过率最高。碱/酸两步催化法制备的增透膜与水的接触角仅为11.3°,本文进一步用六甲基二硅氧烷(HMDS)对增透膜表面进行了修饰,修饰后增透膜的接触角提高至52.5°,增透膜的疏水性及环境稳定性得到较大的提高。     

耐环境性SiO2/SiO2-TiO2 增透膜的设计与制备

根据膜层设计理论设计出以K9玻璃为基体的耐环境性的双层增透膜, 这种增透膜在特定波长处具有超高的透过率. 以盐酸为催化剂, 分别以正硅酸乙酯和钛酸丁酯为前驱体制备了SiO2和TiO2溶胶, 将SiO2和TiO2溶胶按一定比例混合得到SiO2-TiO2复合溶胶. 通过改变复合溶胶中SiO2的含量调节复合膜的折射率, 通过改变提拉速度控制薄膜的厚度. 实验结果表明, 双层增透膜在550 nm处的透过率达到99.9%. 增透膜经较强机械摩擦后峰值透过率基本保持不变, 表明该增透膜具有优良的耐摩擦性. 进一步采用六甲基二硅氮烷对增透膜表面进行修饰, 修饰后增透膜的接触角增大至98.3°, 增透膜的疏水性及环境稳定性得到较大提高.     

Isoelectric focusing sample injection for capillary electrophoresis of proteins

Carrier ampholyte-free isoelectric focusing (IEF) sample injection (concentration) for capillary electrophoresis (CE) is realized in a single capillary. A short section of porous capillary wall was made near the injection end of a capillary by HF etching. In the etching process, an electric voltage was applied across the etching capillary wall and electric current was monitored. When an electric current through the etching capillary was observed, the capillary wall became porous. The etched part was fixed in a vial, where NaOH solution with a certain concentration was added during the sample injection. The whole capillary was filled with pH 3.0 running buffer. The inlet end vial was filled with protein sample dissolved in the running buffer. An electric voltage was applied across the inlet end vial and etched porous wall. A neutralization reaction occurs at the boundary (interface) of the fronts of H+ and OH-. A pH step or sharp pH gradient exists across the boundary. When positive protein ions electromigrate to the boundary from the sample vial, they are isoelectricelly focused at points corresponding to their pH. After a certain period of concentration, a high voltage is applied across the whole capillary and a conventional CE is followed. An over 100-fold concentration factor has been easily obtained for three model proteins (bovine serum albumin, lysozyme, ribonuclease A). Furthermore, the IEF sample concentration and its dynamics have been visually observed with the whole-column imaging technique. Its merits and remaining problem have been discussed, too.     

A problem in etching Pyrex glass capillary columns

Recent attempts to reproduce a literature method for etching of Pyrex glass capillary columns with ?etching ether”? resulted in reduction of the columns to dust through a violent explosion. Although modifications of the method produced etched columns, we found that less than satisfactory results were achieved. Introduction of etching ether by simply coating the column with a thin film of the ether produced an evenly etched column with well defined whiskers. Several observations made during the etching process will also be discussed.     

PVB掺杂有机无机复合SiO2增透膜的制备和表征

以聚乙烯醇缩丁醛(PVB)为有机掺杂剂,正硅酸乙酯为前驱体,氨水为催化剂,利用溶胶-凝胶法制备出了一种新型的有机无机复合二氧化硅增透膜。采用红外光谱、X射线衍射、粒度分析、紫外分光光度法、椭偏测定、原子力显微镜、静滴接触角测量等对膜层性质进行了表征。结果表明：PVB分子的引入并没有引起增透膜结构的变化。在相同的实验条件下,未经PVB掺杂的SiO₂增透膜在720 nm处的峰值透过率为99.8％,而PVB掺杂后的SiO₂复合膜在840 nm处的峰值透过率在99.9%以上。掺杂膜层变厚,峰值透过率朝长波方向移动。掺杂前后增透膜对水的接触角从29°增加到71°,膜层的疏水性得到明显提高。     

Some investigations into the coating of glass open-tube columns

Summary The etching of soda glass by hydrogen chloride has been studied by determining the weight of sodium chloride per unit area on single and double statically-etched glass. The influence of three coating solvents on the critical surface tension of etched and unetched glass has been determined by measuring the contact angles of a wide range of stationary phases. The dynamic coating procedure has been critically examined and certain aspects which lead to the production of improved columns are explored.     

White luminescence of Tm-Dy ions co-doped aluminoborosilicate glasses under UV light excitation

Tm³⁺ and Dy³⁺ ions co-doped aluminoborosilicate glasses were prepared in this study. The luminescence properties of the glasses were analyzed. A combination of blue, green, yellow, and red emission bands was shown for these glasses, and white light emission could be observed under UV light excitation. White light luminescence color could be changed by varying the excitation wavelength. Concentration quenching effect was investigated in this paper. Furthermore, the dependence of luminescence properties on glass compositions was studied. Results showed that the luminescence intensity changed with different network modifier oxides, while the white color luminescence was not affected significantly.     

Long pathlength, three-dimensional absorbance microchip

A long pathlength, three-dimensional U-type flow cell was microfabricated and evaluated for improved absorbance detection on a glass microdevice. A small diameter hole (75 μm) was laser etched in a thin glass substrate whose thickness (100 μm) defined much of the pathlength of the cell. This substrate was thermally bonded and sandwiched between two different glass substrates. The top substrate contained a typical injection cross and separation microchannel. Projecting out of the plane of the separation device was a 126 μm pathlength flow cell as defined by the laser etched hole and the attached microchannels. The flow cell was connected to a microchannel on the bottom substrate that led to a waste reservoir. The planar, flat windows on the top and bottom of this device made light introduction and collection a simple matter using a light emitting diode (LED) and microscope objective. The experimentally obtained detection limit for rhodamine B was determined to be 0.95 μM, which is nearly identical to the theoretical limit calculated by Beer's Law. A separation of three fluorescent dyes was performed, and direct comparisons were made between the transmittance changes through the narrow pathlength separation microchannel and the adjacent long pathlength, three-dimensional U-type flow cell.     

金属铜表面的三维齿状图形的化学微加工

金属铜表面的三维齿状图形的化学微加工;约束刻蚀剂层技术(CELT);化学刻蚀     

镍表面三维微图形的复制加工

运用约束刻蚀剂层技术(CELT)在金属镍(Ni)表面实现三维微图形加工,以规整的三维齿状微结构作模板,获得可有效CELT加工的化学刻蚀和捕捉体系,在Ni表面得到了与齿状结构互补的三维微结构并应用扫描电子显微镜(SEM)和原子力显微镜(AFM)表征刻蚀图案,证实CELT可用于金属表面Ni的三维微图形刻蚀加工．     

Direct-write multiphoton photolithography: a systematic study of the etching behaviors in various commercial polymers

The nonlinear optical processes involved in etching thin polymer films by direct-write multiphoton photolithographic methods (Higgins et al. Appl. Phys. Lett. 2006, 88, 184101) are systematically explored. Power-dependent etching data are obtained for thin films of several commercial polymers, including poly(methyl methacrylate) (PMMA), polystyrene (PS), poly(butyl methacrylate) (PBMA), and poly[2-(3-thienyl)ethyloxy-4-butylsulfonate] (PTEBS). Femtosecond pulses of light from a Ti:sapphire laser are focused to a diffraction limited spot of approximately 570 nm 1/e2 diameter in the films to induce etching. The power dependence of etching in each polymer is used to determine the order of the nonlinear optical process involved. The results for PMMA and PBMA, both of which absorb to the blue of 240 nm, demonstrate that etching involves absorption of several (i.e., 4-6) photons by the polymer, whereas PS, which absorbs wavelengths shorter than 280 nm, is etched by a lower-order process involving fewer (i.e., 3-4) photons. PTEBS, a conducting polymer that absorbs in the visible, is etched by a two-photon process. The results are consistent with an etching mechanism that involves multiphoton-induced depolymerization of the polymer, followed by vaporization of the resulting fragments. The etching resolution is found to be highest for polymers having high glass transition temperatures, low molecular weights, and no visible absorption. Among the polymers examined, low molecular weight PMMA is concluded to be the best polymer for use with this lithographic method. Finally, soft lithography is used to transfer patterns produced in a PMMA film onto poly(dimethylsiloxane), demonstrating a simple means for fabricating submicrometer-scale structures for use in micro- and nanofluidic devices.     

Facile and robust strategy to antireflective photo-curing coating through self-wrinkling

We reported a facile and bio-inspired strategy for obtaining antireflective(AR) coating through polymerization-induced self-wrinkling. Upon irradiation of light, the complex wrinkle micro-patterns with different morphologies were generated spontaneously on the surface of coating during photo-crosslinking, which enables the photo-curing coating can decrease reflection. The resulting photo-curing coating exhibits a high transmittance over 90% and low reflection below 5%～8%, with an efficiency antireflection of 4%～7% compared to the flat blank coating. The successful application of these AR coatings with wrinkles pattern to encapsulate the thin film solar cells results in appreciable photovoltaic performance improvement of more than 4%～8%, which benefits from the decrease of the light reflection and increase of optical paths in the photoactive layer by the introduction of wrinkling pattern.Furthermore, the efficiency improvements of the solar cells are more obvious, with a remarkable increase of 8.5%, at oblique light incident angle than that with vertical light incident angle     

Blue‐light‐emitting and anodically electrochromic materials of new wholly aromatic polyamides derived from the high‐efficiency chromophore 4,4′‐dicarboxy‐4″‐methyltriphenylamine

A series of organosoluble, aromatic polyamides were synthesized from a 4‐methyl‐substituted, triphenylamine‐containing, aromatic diacid monomer, 4,4′‐dicarboxy‐4″‐methyltriphenylamine, which is a blue‐light (454‐nm) emitter with a fluorescence quantum efficiency of 46%. These triphenylamine‐based, high‐performance polymers had strong fluorescence emissions in the blue region with high quantum yields up to 64% and one reversible oxidation redox couple around 1.20 V versus Ag/AgCl in acetonitrile solutions. They exhibited good thermal stability, with 10% weight loss temperatures above 480 °C under a nitrogen atmosphere and with relatively high glass‐transition temperatures (252–309 °C). All the polyamides revealed excellent stability of electrochromic characteristics, changing color from the original pale yellow to blue. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4095–4107, 2006     

Etching and annealing studies of nuclear tracks in glasses

A series of etching and annealing experiments are designed to evaluate the characteristics of fission tracks in a number of glasses of varying silica content. A comparative study has been made by comparing the calculated value of bulk etch rate, optimum etch time and annealing rate for each glass. The present investigation suggests that both bulk etch rate (V_G) and annealing rate (V_a) increases with the decrease in silica content of glasses. A minimum value of these parameters is observed for pure silica glass.     

A study of Roman glass by reflectance and electron paramagnetic resonance spectroscopies

Reflectance and electron paramagnetic resonance (EPR) spectroscopies were used to study 25 fragments of Roman glass. Colour coordinates were used for an unbiased classification of the glasses in colour groups, which accounted for the presence of blue, blue-green, green, yellow-green, yellow and purple samples. Reflectance spectra were recorded in the 250–2500 nm wavelength range and showed absorption bands characteristic of Fe^II, Fe^III and Mn^III ions; furthermore, Co^II and Cu^II bands were observed in the spectra of the blue glasses. A decrease of the absorbance ratio of Fe^II to Fe^III ions was observed moving from blue-green to green and yellow-green glasses; however, yellow fragments still proved to be reduced glasses. EPR spectra displayed the characteristic patterns of Fe^III and Mn^II ions, with g-values in the 2–5 interval and spectral features depending on the relative content of the two elements. The characteristic pattern of the V^IV ion (g ≈ 2) and signals due to the formation of iron-sulphur complexes (g ≈ 6) appeared in the spectrum of a dark yellow glass, recorded at 77 K.     

多孔TiO2薄膜的表面微结构对甲基橙光催化脱色的影响

 从含聚乙二醇的钛醇盐溶胶前驱体出发,通过浸渍提拉法在玻璃表面制备了锐钛矿型多孔TiO2薄膜．随着前驱物中聚乙二醇加入量及分子量的增加,聚乙二醇热分解后在薄膜中产生气孔的数量增多,孔径增大,TiO2薄膜表面的羟基含量也增加．TiO2薄膜中引入适当大小的微孔可明显提高薄膜的光催化活性;当孔径接近400nm时,光的散射增强,透光率下降,薄膜的光催化活性降低．