Characterization of borosilicate

Aloy, A. S., Iskhakova, O. A., Koltsova, T. I., Trofimenko, A. V. Jardine, L. J. 2001. Development and characterization of borosilicate glasses for immobilization of plutonium-containing sludges. Materials Research Society Symposium Proceedings, 663, 189-198. 

Characterization of Borosilicate Glass-Containing Savannah River Plant Radioactive Waste... 

R. O. Schwenker, Etch rate characterization of borosilicate glasses as diffusion sources, J. Electrochem. Soc. 118j 313, 1971. 

In the past ten years the number of chemistry-related research problems in the nuclear industry has increased dramatically. Many of these are related to surface or interfacial chemistry. Some applications are reviewed in the areas of waste management, activity transport in coolants, fuel fabrication, component development, reactor safety studies, and fuel reprocessing. Three recent studies in surface analysis are discussed in further detail in this paper. The first concerns the initial corrosion mechanisms of borosilicate glass used in high level waste encapsulation. The second deals with the effects of residual chloride contamination on nuclear reactor contaminants. Finally, some surface studies of the high temperature oxidation of Alloys 600 and 800 are outlined such characterizations are part of the effort to develop more protective surface films for nuclear reactor applications. ... 

Similar methods have been used to prepare CdS NCs in optical quality borosilicate glasses." Nonlinear optical characterization of one composite sample with particle sizes ranging from 2.5-5.5nm yielded a range for of 10 -10 esu. Optical gain measurements of a similar material afforded a value of 33 cm at room temperature. At 11 K, maximum gain values reached 200 cm , and like the optical nonlinearities, these values were also dependent on NC concentration. ... 

Crystalline borosilicate molecular sieves have been the object of an intensive investigation effort since they were reported in the open literature at the Fifth International Conference on Zeolites by Taramasso, et al. (1) A wide range of structures containing framework boron have been synthesized. The physical properties of these borosilicate molecular sieves have been studied by such techniques as X-ray diffraction, infrared and nuclear magnetic resonance spectroscopies, and temperature programmed desorption of ammonia. In addition, the catalytic performance of borosilicate molecular sieves has been reported for such reactions as xylene isomerization, benzene alkylation, butane dehydroisomerization, and methanol conversion. This paper will review currently available information about the synthesis, characterization, and catalytic performance of borosilicate molecular sieves. 

Silylation of borosilicate with APTS (Y-aminopropyl)triethoxysilane) was attempted as a tool to improve its incorporation in PI (polyimide) films (Vankelecom et al. 1996). This was achieved by a minimal coverage of zeolite crystals with APTS, as evidenced by the characterization of silylation through xylene sorptions, NMR spectroscopy, and measurements of the specific surface of the zeolites. Silylated zeolite was incorporated in PI films on which tensile strength, density, and xylene sorption were measured. Indeed, the density and tensile strength measurements on these composite PI membranes proved a better incorporation of borosilicates after silylation with APTS without changing xylene sorption. 

Roderick, J. M., Holland, D. Scales, C. R. 2000. Characterization and radiation resistance of a mixed-alkali borosilicate glass for high level waste vitrification. Materials Research Society Symposium Proceedings, 608, 721-726. 

In this section, single-component diffusion in zeolites [20,87-92], with the help of the case study of the diffusion of p-xylene and o-xylene in H-ZSM-11 and H-SSZ-24 zeolites, is discussed [90], SSZ-24 is a 12-MR zeolite that was first obtained as the silicon counterpart of AlP04-5, and, later, was obtained as a borosilicate (B-SSZ-24), which could be exchanged with A1 to yield the H-SSZ-24 zeolite [111], This zeolite exhibits the AFI framework, which embodies a one-dimensional channel network without cavities, consisting of parallel 12-MR channels with a free-channel diameter, ow = 7.0A [112], Additionally, ZSM-11 encloses an intersecting two-directional 10-MR channel system, where the two-dimensional channel system is characterized by the free-channel diameter, ow = 5.8 A [112],... 

The polypeptide polyalanine was synthesized1 and characterized by Matrix Assisted Laser Desorption Ionization (MALDI) and amino acid hydrolyses. Monolayers of either l- or D-polyalanine polypeptides, in the form of an a-helix, were prepared by self-assembly on a borosilicate slide that was coated with a 200-300 nm thick gold film (Metallhandel Schroer Gmbh). Prior to the adsorption, the gold slides were annealed by flame and only then inserted into a 1 mM peptide solution of... 

Ultrathin porous glass membranes with variable texture properties were prepared from a Si02-rich sodium borosilicate initial glass by careful fine timing of the conditions of heat treatment for phase-separation. Pore sizes between < 1 and 120 nm can be realized. The membranes are characterized by a narrow pore size distribution. The transport, optical and mechanical properties vary with the pore size. The tailorable texture and transport characteris-... 

This review concerns the synthesis, characterization, and catalytic activity of microporous ferrierite zeolites and octahedral molecular sieves (QMS) and octahedral layer (OL) complexes of mixed valent manganese oxides. The ferrierite zeolite materials along with borosilicate materials have been studied as catalysts for the isomerization of n-butenes to isobutylene, which is an important intermediate in the production of methyltertiarybutylether (MTBE). The CMS materials have tunnels on the order of 4.6 to 6.9 A. These materials have been used in the total oxidation of CO to C02, decomposition of H2O2. dehydrogenation of CeHi4, C0H14 oxidation, 1-C4H3 isomerization, and CH4 oxidation. The manuscript will be divided into two major areas that describes zeolites and OMS/OL materials. Each of these two sections will include a discussion of synthesis, characterization, and catalytic activity. 

A particularly illustrative example of the dependence of film microstructure on the size, structure, and condensation rate of the depositing silicate phase is that of a borosilicate sol deposited at pH 3 after various periods of aging at 50 °C (122). The borosilicate species are characterized by a mass fractal dimension D — 2.4. Aging at 50 °C causes them to grow in size as indicated by the plot of hydrodynamic radius versus aging time in Figure 18. Corresponding refractive indices of films deposited from the... 

In this paper we report new methods for the lattice substitution of heteroatoms in large and extra-large pore borosilicate zeolites via post-synthetic treatment to prepare catalytically more active zeolites. Ga-SSZ-33, Al-SSZ-33 and Al-UTD-1 prepared from B-SSZ-33 and B-UTD-1, respectively, are discussed as examples. The materials are characterized with various physicochemical techniques and catalytic reactions. In particular, the advance of these methods is demonstrated by the exceptionally high activity of the resulting Al-SSZ-33 for acid-catalyzed hydrocarbon conversions. 

The platinum/ruthenium mixture is then fired with the same firing cycle. The ratio of platinum to ruthenium is 1 1 [2,50] with the effective concentration, based on the flat area of the disc, applied to the substrate being 4 mg cm" [35,51]. The voltage-discharge curves of a coimnercially available fuel cell (H-Tec Methanol Fuel Cell Junior) was characterized. The cell was disassembled and the Ag-coated borosilicate anode was inserted and retested. 

The resolving power of this instrument in purified nitrogen was typically 20 to 50 and could reach 75 under optimal conditions. A related work emphasized analytical values showing that PAHs as adsorbates on borosilicate glass could be determined (Figure 5.9) at 40-pg levels or 5.5 to 7 pg/mm using LDI-IMS in air at ambient pressure and 100°C for ion characterization in the drift tube. ... 

The combination of infiltration and reaction that characterizes DMO has been exploited to make a number of composites. As long ago as 1953, it was shown that silica containing refractories were reduced by molten aluminum to form alumina and silicon [4], Subsequently [27], the displacement reaction was extended to the formation of composites of alumina with residual Al-Si. More recently, the Al-Si02 displacement reaction has been used in the infiltration of dense preforms of silica [28] and mullite [29,30] by molten aluminum. Extension of the reactive infiltration process to porous silica-containing preforms [31,32] has resulted in the fabrication of metal-matrix composites in which the silica was replaced by a mixture of about 65% alumina and 35% metal, while the pores were infiltrated by molten alloy. In contrast to DMO, the displacement reaction appears to proceed at a critical temperature of 1100-1200°C and without the need for a volatile solute element or oxygen. Borosilicate glass has also been used as an initiator to enable the infiltration of Al-Si alloys into alumina preforms [33]. 

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