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1.
Electrosprayed spots of varying thickness were evaluated for use as reproducible, homogenous, high efficiency MALDI samples. Thin samples on stainless steel plates were found to give exceptionally strong signals, as did the last layers of thick samples, when ablated down to the steel substrate. A small enhancement was also observed for thin samples on a gold substrate, and with a few-nanometer gold coating on top of a thick sample. Ion yields and intensity ratios can be understood in the context of the previously described quantitative MALDI model including the matrix-metal interfacial ionization potential reduction effect (Knochenmuss, R.; Anal. Chem. 2004, 76, 3179-3184). The absolute and relative stabilities of ion signals were found to be at least a factor of two better for the thin electrosprayed spots, compared to spots prepared by dried droplet methods.  相似文献   

2.
The effect of UV-curing time on the mechanism of interaction between the various precursor phases in a novel sol–gel-derived organic–inorganic hybrid coating material and the resulting mechanical and thermal properties of this material when coated onto substrates in thin film form have been examined using a variety of chemical and physical characterisation methods. Microstructurally, the hybrid coating materials examined were all a single amorphous phase and were all optically transparent. The degree of interaction between the organic and inorganic phases, the scratch behaviour of the coating materials and the thermal stability of the coating materials were all found to depend strongly on the UV curing time. For the particular proportions of inorganic and organic components used to make up this hybrid coating material, an optimum UV curing time of 10 min under a UV intensity of 46.3 mW cm−2 was found to produce transparent coatings which adhered well to the substrates and which were robust in scratch tests on aluminium and polycarbonate substrates and abrasion tests on polycarbonate substrates.  相似文献   

3.
Hybrid inorganic-organic hard coatings on PMMA substrate were obtained by sol-gel reaction of 3-glycidoxypropyltrimethoxysilane(GPTS), tetramethyl orthosilicate(TMOS) and aluminum butoxyethoxide (Al(OEtOBu)3). The catalytic effect of aluminum butoxyethoxide on inorganic condensation and epoxide polymerization has been studied by 13C, 29Si nuclear magnetic resonance spectroscopy and by Fourier transformed infrared spectroscopy. Hardness of hybrid inorganic-organic materials were measured by nanoindentor and mainly influenced by the extent of epoxide polymerization and inorganic condensation of their coating catalyzed by aluminum butoxyethoxide.  相似文献   

4.
Le Gac S  Arscott S  Rolando C 《Electrophoresis》2003,24(21):3640-3647
We report on the fabrication and testing of planar nib-like structures for nanoelectrospray ionization-mass spectrometry (nanoESI-MS) applications. The micro-nib structures were fabricated on silicon substrates using the negative photoresist SU-8; they include capillary slots with widths of 8 and 16 microm. A suitable wafer cleaving step made the nib-like structures overhang the edge of a silicon substrate to provide a robust interface for nanoESI-MS applications; this freeing of the nib tip from the wafer surface created a point-like structure that is essential to establish an electrospray. The micro-nib sources were successfully tested on an LCQ Deca XP+ ion trap mass spectrometer using peptide samples at concentrations down to 1 microM. The high voltage was applied using a platinum wire inserted in the sample reservoir upstream to the capillary slot. A Taylor cone was clearly seen at the nib tip. The micro-nibs performed well at voltages as low as 0.8 kV; such performances are state-of-the-art with respect to current micromachined ESI-MS interfaces and are conditions comparable to those used for standard emitter tips. In addition, we clearly observed the influence of the micro-nib slot width on the ionization performances: the narrower the slot, the better the performances.  相似文献   

5.
Yttria stabilised Zirconia coatings on polycrystalline silicon wafers have been performed using physical vapor deposition with negative bias applied to the substrate. The thicknesses determined by ellipsometry were between 45 and 70 nm and the deposition rate was about 0.25 nm per min. Secondary ion mass spectroscopy analyses revealed no interdiffusion of metallic elements between the zirconia coating and silicon substrate. Grazing incidence X-ray diffraction indicates that the coatings are crystallized, but it can not permit to identify all the crystalline phases. The disparity between the experimental and the k-ratios (Pouchou and Pichoir simulation of electron probe microanalysis analyses) showed the usefulness of others techniques to determine coating and interface compositions. Cross sectional transmission electron microscopy observations demonstrate an amorphous layer between the zirconia coating and the substrate with a thickness of 30–120 nm. If it is considered to be an amorphous silicon layer, the PAP simulation based on the ellipsometric thicknesses and an yttria stabilised zirconia density of 4 g/cm3 fits correctly the experimental values.  相似文献   

6.
近年来,表面引发聚合制备聚合物刷,由于其能控制无机物表面性能,在材料科学方面有广泛的应用前景.在制备聚合物刷的一系列聚合方法中,“活性”/可控自由基聚合,尤其是原子转移自由基聚合(Atom Transfer Radical Polymerization,ATRP)得到广泛使用.它可获得分子量分布较窄的结构规整的聚合物,可将一些功能性的单体引入聚合物体系获得功能聚合物,  相似文献   

7.
Arc ion plating(AIP) is applied to form Ti/(Ti,Cr)N/Cr N multilayer coating on the surface of 316 L stainless steel(SS316L) as bipolar plates for proton exchange membrane fuel cells(PEMFCs). The characterizations of the coating are analyzed by scanning electron microscopy(SEM) and X-ray diffraction(XRD). Interfacial contact resistance(ICR) between the coated sample and carbon paper is 4.9 m cm~2 under 150 N/cm~2,which is much lower than that of the SS316 L substrate. Potentiodynamic and potentiostatic tests are performed in the simulated PEMFC working conditions to investigate the corrosion behaviors of the coated sample. Superior anticorrosion performance is observed for the coated sample, whose corrosion current density is 0.12 μA/cm2. Surface morphology results after corrosion tests indicate that the substrate is well protected by the multilayer coating. Performances of the single cell with the multilayer coated SS316 L bipolar plate are improved significantly compared with that of the cell with the uncoated SS316 L bipolar plate, presenting a great potential for PEMFC application.  相似文献   

8.
A rotating ball interface for surface‐assisted laser desorption/ionization (SALDI) mass spectrometry was designed and tested. One side of the ball was exposed to atmospheric pressure and the other to the vacuum in a time‐of‐flight mass spectrometer. Analytes (arginine, atenolol, reserpine, tofisopam, and chloropyramine) were applied using electrospray to a silicon substrate on the atmospheric side, the ball was rotated 180°, and the analyte was desorbed on the vacuum side using a pulsed, 200 Hz, 355 nm laser. In order to increase the desorption area, the laser focus was scanned over the substrate in a raster pattern repeated once every second. The design allows for rapid sample throughout with a sample turn‐around time as short as 5 s. Newly produced porous silicon substrates initially yielded very low ion signals, and they required several hundred laser shots to attain maximum sensitivity. In contrast, amorphous silicon did not require such ‘activation’. Quantitative analysis showed a sample‐to‐sample reproducibility of about 10%. The sensitivities with model analytes were in the 1000 to 10 000 ions/fmole range and detection limits in the low fg range. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

9.
To improve the electrochemical performances of Si thin film anodes for lithium rechargeable batteries, fullerene thin films are prepared by plasma-assisted evaporation methods to be used as coating materials. Analyses via Raman and X-ray photoelectron spectroscopy indicate that amorphous polymeric films originated from fullerene are formed on the surface of the silicon thin film. The electrochemical performance of these fullerene-coated silicon thin film as an anode material for rechargeable lithium batteries has been investigated by cyclic voltammetry, charge/discharge tests, and electrochemical impedance spectroscopy. The fullerene-coated Si thin films demonstrated a high specific capacity of above 3,000 mAh g−1 as well as good capacity retention for 40 cycles. In comparison with bare silicon anodes, the fullerene-coated silicon thin film showed superior and stable cycle performance which can be attributed to the fullerene coating layer which enhances the Li-ion kinetic property at the electrode/electrolyte interface.  相似文献   

10.
The objective of the present study was to introduce a cost-effective and environmentally friendly coating to improve the corrosion resistance of the structures located in salt water. The coating solution, based on amorphous aluminum phosphate composition, was synthesized by sol–gel process and applied to AISI 304 stainless steel by dip coating technique. X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy analyses were employed to investigate the phase composition and morphology of the coating. Corrosion behavior of the uncoated and coated samples was investigated using standard salt spray test, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) in 3.5 wt.% NaCl solution. Salt spray test results for the bare substrate revealed a corrosion rate of six-time greater than that of the coated surface after 168 hr exposure time. Electrochemical test results declared that the amorphous AlPO4 coating decreased the corrosion current density of the AISI 304 stainless steel by 10 orders of magnitude. Furthermore, according to the corresponding EIS measurements, the coated surface exhibited a superior anti-corrosion performance than uncoated sample. Overall, the results declared that the amorphous AlPO4 coating could be a good choice for surface protection of stainless steel against electrochemical corrosion in salty environments.  相似文献   

11.
Silicon nanowire arrays (SiNWs) on a planar silicon wafer can be fabricated by a simple metal-assisted wet chemical etching method. They can offer an excellent light harvesting capability through light scattering and trapping. In this work, we demonstrated that the organic-inorganic solar cell based on hybrid composites of conjugated molecules and SiNWs on a planar substrate yielded an excellent power conversion efficiency (PCE) of 9.70%. The high efficiency was ascribed to two aspects: one was the improvement of the light absorption by SiNWs structure on the planar components; the other was the enhancement of charge extraction efficiency, resulting from the novel top contact by forming a thin organic layer shell around the individual silicon nanowire. On the contrary, the sole planar junction solar cell only exhibited a PCE of 6.01%, due to the lower light trapping capability and the less hole extraction efficiency. It indicated that both the SiNWs structure and the thin organic layer top contact were critical to achieve a high performance organic/silicon solar cell.  相似文献   

12.
To enhance sample signals and improve homogeneity in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) analysis, a simple, rapid, and efficient sample preparation method was developed in this study. Polydimethylsiloxane (PDMS) was coated on a stainless steel MALDI plate, forming a transparent, hydrophobic surface that enhanced sample signals without producing observable background signals. Compared to the use of an unmodified commercial metal MALDI plate, peptide signals were enhanced by ~7.1–11.0-fold due to the reduced sample spot area of the PDMS-coated plate, and showed improved peptide mass fingerprinting (PMF) and MS/MS peptide sequencing results. In the analysis of phosphopeptides and carbohydrates with a 2,5-dihydroxybenzoic acid (DHB) matrix, the PDMS-coated plate showed improved sample homogeneity and signal enhancements of ~5.2–8.2-fold and ~2.8–3.2-fold, respectively. Improved sensitivity in the observation of more unique fragment ions by MS/MS analysis, to successfully distinguish isomeric carbohydrates, was also illustrated. In protein analysis with a sinapinic acid (SA) matrix, a ~3.4-fold signal enhancement was observed. The PDMS film coating was easily removed and refabricated to avoid sample carryover, and was applicable to diverse commercial MALDI plates. The PDMS-coated approach is a simple, practical, and attractive method for enhancing analyte signals and homogeneity.  相似文献   

13.
A novel inorganic-organic siloxane hybrid material with self-adhesion ability and high refractive index for high-power light emitting diodes (LEDs) encapsulation is introduced. Under the catalysis of an anion exchange resin, the hybrid material was synthesized by a sol-gel condensation process from methacryloxy propyl trimethoxyl silane (MPTS), γ-(2, 3-epoxypropoxy)propytrimethoxysilane (EPTS) and diphenylsilanediol (DPSD). This hybrid material was characterized by Fourier-transform infrared spectroscopy and 1H-NMR. The resin-type encapsulation material was then prepared by hydrosilylation of the newly synthesized inorganic-organic siloxane hybrid material and methylphenyl hydrogen-containing silicone resin. The cured silicone resin-type encapsulation material can be used as a LEDs encapsulant, owing to high refractive index (n = 1.544), high transparency, appropriate hardness, and excellent thermal stability, as well as good adhesive strength between the encapsulating material and the substrate of LED lead frame.  相似文献   

14.
With a view to developing an economical and elegant biosensor chip, we compared the efficiencies of biosensors that use gold-coated single-crystal silicon and amorphous glass substrates. The reflectivity of light over a wide range of wavelengths was higher from gold layer coated single-crystal silicon substrates than from glass substrates. Furthermore, the efficiency of reflection from gold layers of two different thicknesses was examined. The thicker gold layer (100 nm) on the single-crystal silicon showed a higher reflectivity than the thinner gold film (10 nm). The formation of a nucleic acid duplex and aptamer–ligand interactions were evaluated on these gold layers, and a crystalline silicon substrate coated with the 100-nm-thick gold layer is proposed as an alternative substrate for studies of interactions of biomolecules.  相似文献   

15.
We demonstrate a simple method for the fabrication of rough silicon surfaces with micro- and nanostructures, which exhibited superhydrophobic behaviors. Hierarchically rough silicon surfaces were prepared by copper (Cu)-assisted chemical etching process where Cu nanoparticles having particle size of 10-30 nm were deposited on silicon surface, depending on the period of time of electroless Cu plating. Surface roughness was controlled by both the size of Cu nanoparticles and etching conditions. As-synthesized rough silicon surfaces showed water contact angles ranging from 93° to 149°. Moreover, the hierarchically rough silicon surfaces were chemically modified by spin-coating of a thin layer of Teflon precursor with low surface energy. And thus it exhibited nonsticky and enhanced hydrophobic properties with extremely high contact angle of nearly 180°.  相似文献   

16.
聚多巴胺还原高锰酸钾制备二氧化锰阵列纳米管   总被引:1,自引:1,他引:0  
以通过水热法在石英玻璃片表面合成的ZnO纳米棒为模板,在其表面生成聚多巴胺薄膜,然后与KMnO4反应,制备了MnO_2阵列纳米管。经表征发现,制备的MnO_2纳米管形态良好,在基底表面的附着力强;所制备的MnO_2为非晶型。由于ZnO模板易合成、易去除、形态好,且聚多巴胺薄膜的生成方法也很简便易行,使得该制备MnO_2纳米管阵列的方法具有简便、快捷、适用性广等的特性,对MnO_2新形态纳米结构的构建具有一定的启示作用。  相似文献   

17.
This study presents a microbead-packed PDMS microchip with an integrated electrospray emitter for sample pretreatment prior to sheathless ESI-MS. We prove the concept of analytical functions integrated onto a cm-sized area of a single bulk material. The microchip consists of two PDMS substrates replicated from SU-8 fabricated silicon wafer masters, bonded together after oxidation by corona discharge treatment. The channel within the microchip contains a grid structure that was used to trap 5 microm hypercross-linked polystyrene beads. The beads acted as a medium for sample desalting and enrichment. Electrical contact for the sheathless ESI process was achieved by coating the integrated emitter with conductive graphite powder after applying a thin layer of PDMS as glue. The coating as well as the bond of the PDMS structures showed excellent durability. A continuous spray was obtained from the microchip for over 800 h in a long-term electrospray stability experiment. Desalting and enrichment of neuropeptides from a physiological salt solution was successful by loading the sample onto the packed beads, followed by a washing and an eluting step. The results were obtained and evaluated using a TOF MS. An LOD of approximately 20 fmol (loaded onto the beads) for angiotensin II was obtained from a sample of neuropeptides dissolved in physiological salt solution.  相似文献   

18.
A new type of inorganic-organic hybrid materials incorporating gelatin and 3-(glycidoxypropyl) trimethoxysilane (GPSM) was prepared through sol-gel processing. A solid-state 29Si NMR analysis indicated that all the methoxy silane groups of GPSM were polymerized to yield —Si—O—Si— bridging bonds. An amino acid analysis confirmed grafting reactions of GPSM against gelatin chains. The increasing GPSM/gelatin ratio stimulated gel formation, phase separation, and the density of GPSM-crosslinking of the gelatin chains as well as it changed the micro- and macro- structures and the viscoelastic properties of the final products.  相似文献   

19.
掺硼p型非晶硅薄膜的制备及光学性能的表征   总被引:1,自引:0,他引:1  
以高氢稀释的硅烷(SiH4 )为反应气体,硼烷(B2H6)为掺杂气体,利用RF-PECVD方法,在玻璃衬底上制备出掺硼的氢化非晶硅(a-Si:H)薄膜,研究了硼掺杂量对氢化非晶硅(a-Si:H)薄膜的光学性能的影响.利用NKD-7000 W光学薄膜分析系统测试薄膜的透射谱和反射谱,并利用该系统的软件拟合得出薄膜的折射率、消光系数、吸收系数等光学性能参数,利用Tauc法计算掺硼的非晶硅薄膜的光学带隙.实验结果表明,随着硼掺杂量的增加,掺杂非晶硅薄膜样品在同一波长处的折射率先增大后减小,而且每一样品均随着入射光波长的增加而减小,在波长500 nm处的折射率均达到4.3以上;薄膜的消光系数和吸收系数随着硼掺杂量的增大而增大,在500 nm处的吸收系数可高达1.5×105cm-1.在实验的硼掺杂范围内,光学带隙从1.81 eV变化到1.71 eV.  相似文献   

20.
This work, we report a cost effective method to decompose ITO thin layer on polycarbonate as flexible substrate by means of spin coating technique. Three calcinations techniques were carried out. The coating were deposited by spin and cured by heat, ultraviolet (UV) irradiation and Nd-YAG pulse laser. The resistivity change on annealing of the amorphous film by thermal, UV and laser was investigated by X-ray diffraction, scanning electron microscopy, atomic force spectroscopy and UV–Vis spectrometer. It is shown that the resistance of coated film on polymer decreases dramatically to less than impedance spectroscopy (600 Ω) when using combination of low heat treatment and laser irradiation with a wavelength of 1,100 nm and energy of 6–25 J.  相似文献   

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