Investigation of Glasses Using Surface Profiling by Spectrochemical Analysis of Sputter-Induced Radiation: I, Surface Profiling Technique with High In-Depth Resolution

Experimental equipment was developed to investigate concentration gradients in solid surface layers; the radiative de-excitation of elements and molecules which are ejected from the ion beam-bombarded solid and the luminescence excitation within the surface layer are recorded spectrographically. Examples show how elemental composition profiles can be calibrated with respect to depth. An in-depth resolution of a few nanometers can be obtained. The original profiles are distorted by energy and charge transfer and by other peculiarities connected with ion-beam etching; the extent to which these distortions must be taken into consideration in interpreting the results is discussed. Interdiffusion-controlled solid-state reactions of thin oxide films with a glass substrate were investigated. Advantages and disadvantages of the method for analysis and concentration profiling of glass surfaces and oxide layers on glasses in glass research and industry are discussed.     

Interpretation of Hydrated States of Sodium Silicate Glasses by Infrared and Raman Analysis

Infrared spectra of thin films (a few micrometers) of hydrated sodium silicate glasses after heating at temperatures from 100° to 400°C were measured in the spectral region from 400 to 4300 cm⁻¹. Also, Raman spectra of hydrated glasses were measured in the region from 100 to 1400 cm⁻¹. Water molecules in hydrated glasses were classified into three types by the bonding configuration: water molecules interacting with Si–OH groups, nonbridging oxygens, and bridging oxygens. On the basis of the fundamental bands observed here, we calculated the wave numbers of the combination-overtone bands of water molecules and SiOH groups in hydrated glasses. The calculated wave numbers satisfactorily agreed with observed wave numbers in the nearinfrared region.     

Investigation of Glasses Using Surface Profiling by Spectrochemical Analysis of Sputter-Induced Radiation: II, Field-Driven Formation and Electrochemical Properties of Protonated Glasses Containing Various Proton Concentrations

The ion-sputtering technique for measuring concentration profiles in glass surfaces provides a method for studying ionic transport in solids. Simultaneous field-driven lithium ion and proton transfer from solutions into, and migration of these ions within, several lithium silicate glasses was investigated quantitatively. This work leads to the new field of protonated glasses which are distinguished by the availability of all sites to both cationic species. Conductivity and mobilities reported as a function of concentration (50°C) do not exhibit the typical features of the mixed-alkali effect. Mechanisms are proposed for ionic transfer across solution-glass interfaces and for migration of ions within protonated glasses. Small proton mobilities at low proton concentrations are explained in terms of specific sites which function as proton traps and are identified by infrared spectroscopy. The condition for stability of boundaries between migrating ions is discussed.     

On-Line Chemical Analysis of Individual Alkali-Containing Aerosol Particles by Surface Ionization Combined with Time-of-Flight Mass Spectrometry

An aerosol mass spectrometer for measurements of the alkali metal content in individual submicron aerosol particles is presented. The instrument combines surface ionization of individual particles on a hot platinum surface with orthogonal acceleration time-of-flight mass spectrometry. The instrument simultaneously provides the content of different alkali metal elements in single particles with high sensitivity. The instrument is characterized in laboratory experiments, and determination of the alkali metal content is demonstrated for particle diameters of 50–500 nm. The technique is demonstrated in ambient air measurements at an urban background site, and sea spray particles and particles originating from biomass burning are identified based on their content of sodium and potassium. Possible further improvements and applications of the technique are discussed.     

The Chemical Differentiation between Sinapis arvensis and Brassica napus Seeds by Surface Wax Analysis

The hydrocarbons were extracted and isolated from the surface of both Sinapis arvensis and Brassica napus seeds. The major hydrocarbon of the weed seed was found to be hentriacontane (C₃₁H₆₄) whereas nonacosane (C₂₉H₆₀) was the predominant hydrocarbon in rapeseed. This can be used as a criterion upon which differentiation can be made. Total “wax” extracts of the two seed types were analysed by gas chromatography. The waxy material extracted from the weed seed was found to have a major peak at 3320 Kovats retention indices which was absent in all rapeseed varieties. By studying a series of known composites of rapeseed and wild mustard, the level of wild mustard contamination could be accurately determined down to a level of 1 % using a ratio of two peaks at 2900 and 3320 Kovats retention indices.     

Structural and nanostructural behavior of deuterium implanted Highly Ordered Pyrolytic Graphite investigated by combined High Resolution Transmission Electron Microscopy,Scanning Electron Microscopy and Raman microspectrometry

This work aims at studying the impact of D⁺ ion implantation and thermal annealing on the organization of Highly Ordered Pyrolytic Graphite (HOPG). Raman microspectrometry, High Resolution Transmission Electron Microscopy (HRTEM) and Scanning Electron Microscopy (SEM) were used to characterize the multiscale organization of HOPG. For the first time, HRTEM images were processed, allowing a better estimation of structural parameters such as size of the graphene layers, mean interlayer spacing, distribution of the relative orientations of the graphene layers, defined as the spatial orientation of the stacked layers. Ion implantation induces a strong disordering of the HOPG reflected by a decrease of the length of graphene layers, and an increase of both angular dispersion and interlayer distance and a significant decrease of the Basic Structural Unit (BSU) diameter. Thermal annealing up to 1000 °C leads to partial reordering of the HOPG, with increase of the mean length of the graphene layers, decrease of their angular dispersion and interlayer distance and larger and increasingly parallel oriented BSUs. Even if the conservation of the lamellar nanostructure favors reordering, the latter is only partial since annealing temperature is far from 2000 °C, temperature above which stiff and perfect layers may be obtained.     

努力打造有国际竞争力的精品化工园区--初析南京化学工业园区的开发和建设

简要介绍了设立南京化学工业园的必要性，优势特点，阐述了化工园区建设对石化工业及地区经济发展的促进作用和现实意义。     

Surface Analysis of Cr2O3‐, CoO‐, and Al2O3‐Doped Iron–Phosphate Glasses at High Temperature

Surface structures of iron–phosphate glasses were examined using X‐ray photoelectron spectroscopy (XPS). Cr₂O₃, CoO, and Al₂O₃ were introduced to the glass by the replacement of a part of Fe₂O₃, and the simulated fission products are also added. The obtained glasses showed high chemical durabilities by MCC‐1 test. In situ high‐temperature and room‐temperature XPS measurements were conducted on the polished sample surfaces and also those after 1‐week chemical durability test. Unique trends were observed in XPS spectra on heating and after the chemical durability test, respectively. Nature of the glass surface of iron–phosphate glasses was explained from the point of view of surface energy, and the origin of high chemical durability and the effect of chromium ions were discussed based on the changes on surface composition and valence states of transition‐metal ions.     

Synthesis of Si-N and B-N Preceramic Coatings on Silica Gel by Chemical Surface Coating: A Porosity Study

Silica gel has been modified by successive gas reactions with (SiCl₄-NH₃) and (BCl₃-NH₃) in order to obtain Si-N and B-N preceramic polymers, which are chemically bound to the substrate surface. The effect of the polymer synsthesis on the porosity characteristics of the substrate is determined as a function of the number of applied modification cycles, using N₂ adsorption-desorption isotherms recorded at 77 K. The elemental analysis data in combination with the adsorption isotherms yield a more detailed picture of the density and the homogeneity of the coatings. Using the pore size distributions, the contribution of pore blocking and pore narrowing can be calculated as a function of the amount of reaction cycles. A new calculation method for the pore blocking and pore narrowing, which is not based on any pore shape model, is also presented and compared with the former calculation method.     

气体多元共渗与化学镀复合处理试样的性能分析

研究了Q235钢经气体多元共渗加化学镀复合处理后，试样表面复合处理层的结构与形貌、显微硬度和抗盐雾腐蚀特性。实验结果表明，复合处理层的结构由Ni-P、NiaP3、NiP4、Fe3N、Fe2N、Fe3O4、Fe2O3和少量的FeS、Fe2C构成，其硬度是气体多元共渗处理后表层硬度的1．6-1．7倍，抗蚀性能相对于单一气体多元共渗或化学镀技术处理大约提高了3．7-5．5倍。     

水热法制备高比表面积介孔TiO2粉体及其光催化性能研究

实验以β环糊精(β-CD)为造孔剂,采用水热法制备了高比表面积介孔TiO2纳米粉体.利用BET、XRD、N2 ad-sorption-sorption等方法对样品进行了测试.考察了水热温度、水热时间、焙烧温度、造孔剂添加量等因素对材料的比表面积及其光催化性能的影响.实验结果表明:当体系的水热温度180℃、水热时间8h、...     

Super‐Resolution Imaging and Quantitative Analysis of Membrane Protein/Lipid Raft Clustering Mediated by Cell‐Surface Self‐Assembly of Hybrid Nanoconjugates

Super‐resolution imaging was used to quantify organizational changes in the plasma membrane after treatment with hybrid nanoconjugates. The nanoconjugates crosslinked CD20 on the surface of malignant B cells, thereby inducing apoptosis. Super‐resolution images were analyzed by using pair‐correlation analysis to determine cluster size and to count the average number of molecules in the clusters. The role of lipid rafts was investigated by pre‐treating cells with a cholesterol chelator and actin destabilizer to prevent lipid raft formation. Lipid raft cluster size correlated with apoptosis induction after treatment with the nanoconjugates. Lipid raft clusters had radii of ～200 nm in cells treated with the hybrid nanoconjugates. Super‐resolution images provided precise molecule location coordinates that could be used to determine density of bound conjugates, cluster size, and number of molecules per cluster.     

Conformation Control of Oligosilanes by Trimethylsilyl Groups: Dodecamethyl-, Undecamethyl-2-trimethylsilyl- and Decamethyl-2, 4-bis(trimethylsilyl)-n-pentasilane Studied by Raman Spectroscopy and Quantum Chemical Calculations

2,4-Bis(trimethylsilyl) substituted n-pentasilane Me₃SiSiMe(SiMe₃)SiMe₂SiMe(SiMe₃)SiMe₃ (1) has been prepared from Me₂SiCl₂ and (SiMe₃)₂SiMeK, and its solid state molecular structure has been determined by single crystal X-ray diffraction. By reaction of 1 with KO^tBu and subsequent treatment of the resulting silyl anion with (MeO)₂SO₂, the novel hexasilane Me₃SiSiMe(SiMe₃)SiMe₂SiMe₂SiMe₃ (2) has been synthesized. By again using the reaction sequence KO^tBu/(MeO)₂SO₂, known n-pentasilane Me₃SiSiMe₂SiMe₂SiMe₂SiMe₃ (3) has been prepared in a novel and very convenient way from 2. All silanes 1, 2, and 3 as well as the intermediate silyl anions obtained from 2 and 3 have been characterized by ²⁹Si and ¹H NMR spectroscopy, 1 and 2 by elemental analyses also. Raman spectra in the temperature range 210–370 K of the pure liquids 1, 2 and 3 as well as of solutions in toluene (1 and 2) or cyclopentane (3) reveal that all of the silanes exist as mixtures of conformers. The symmetric SiSi stretch observed in the range 341 to 363 cm^-1 and possessing by far the largest Raman intensity of all SiSi stretching vibrations splits into five bands for 3 and two bands for 1 and 3. Quantum chemical DFT B3LYP/6–311G(d) calculations located 15 conformational minima for 2 with relative energies up to 19.9 kJmol^-1, and five minima for 1 with relative energies up to 15.5 kJmol^-1. Calculated SiSiSiSi torsion angles vary between 26.2° (smallest value found) and 179.3°, demonstrating the flexibility of backbones composed of silicon.     

Surface organometallic chemistry on metals in water: Chemical modification of platinum catalyst surface by reaction with hydrosoluble organotin complexes: application to the selective dehydrogenation of isobutane to isobutene

Surface organo-metallic chemistry on metals can be a new route to generate supported bimetallic catalysts. According to previous works on Pt–Sn catalysts, the reaction of tetra n-butyl-tin on the reduced platinum surface leads to well-defined bimetallic catalysts which are very active and selective in the dehydrogenation of isobutane into isobutene. The presence of tin not only isolates the surface platinum atoms from each other (EXAFS) and thus prevents a fast deactivation by decreasing the processes of C–C bond cleavage but also favors the regeneration processes under air. So far the catalyst preparations were carried out either in the gas phase or in organic solution (e.g. heptane). However, in order to meet the industrial criteria of process simplicity, there is a need to carry out such catalyst preparation in water.

In this work, Pt–Sn/Al₂O₃ and Pt–Sn/SiO₂ catalysts was prepared by reacting tris n-butyl-tin hydroxide on the platinum surface, in water solution under atmospheric pressure of hydrogen. The kinetics of the reaction was followed by measuring the amount of butane evolved as a function of time. The solids obtained were characterized by CO, O₂ or H₂ chemisorption and electron microscopy (CTEM and EDAX). Clearly, the (n-Bu)₃Sn(OH) reacts selectively on the platinum surface and not with the support, with evolution of butane, leading to a bimetallic catalyst where the platinum atoms are isolated from each other by the tin atoms. Very high selectivities (>95%) and activities were obtained for the reaction of isobutane dehydrogenation into isobutene and it was concluded that surface organo-metallic chemistry on metal in water can be an alternative route to prepare well-defined supported bimetallic Pt–Sn catalysts.     

Combination of Chemical Coagulation and Photo-Fenton Oxidation Process for the Treatment of Beet Sugar Industry Wastewater: Optimization of Process Conditions by Response Surface Methodology

The beet sugar industry generates large volumes of wastewater with high levels of chemical oxygen demand (COD) and color content, which are discharged into the nearby environment without adequate treatment. The aim of this study was to investigate the treatment possibility of this wastewater by using the photo-Fenton oxidation combined with a coagulation process. Central composite design and response surface methodology were used to evaluate the relationships between color and COD reduction and the photo-Fenton oxidation parameters (i.e. Fenton’s reagent dosage, pH, and reaction time).

The combined treatment results showed 59% of COD and 83.9% of color removal were obtained at optimum conditions (pH: 6.2; Fe²⁺ dosage: 20 ppm; H₂O₂ dosage: 1500 ppm; and reaction time of 15 min). Finally, the results of gel permeation chromatography showed that low molecular weight fraction of the wastewater impurities is more degraded than high molecular weight fraction during oxidation/coagulation process. Therefore, the results obtained from this study showed that an appropriate combined method for the treatment of beet sugar industry wastewater can be designed and implemented.