Doping techniques

Figure 5.38 H2 absorption curves starting from NaH-tAI (dehydrided NaAIH4), as a function of added TiCl3 (using the dry TiCl3-NaAIH4 ball-milling/doping technique [65]) catalyst precursor (expressed in mol%). Initial temperature = 125°C. Applied hydrogen pressure ppj =81-90 bar [66].

Polycarbonate films with a typical thickness of 10-15 qm containing 2 wt% of molecularly dispersed BET-TIE are cast following the modified reticulate doping technique (MRDT) (Laukhina et al, 1995) as illustrated in Eig. 3.21. Then the surfaces of the samples are treated with the vapour of a Br2/CH2Cl2 solution. 

The outstanding performance of ACs stems from a unique combination of geometrical and chemical characteristics. Nowadays carbon adsorbents with tailor-made surface area and pore hierarchy are commercially available [1-3]. Chemical treatment, in addition to impregnation or doping techniques, is often used to enhance the performance of porous carbons. Introduction of heteroatoms into the carbon skeleton renders the carbon surface more attractive to polar molecules [4]. 

In contrast to the minimal activity in infrared reflection studies the technique of inelastic electron tunneling spectroscopy (IETS) recently has contributed a large amount of information on monolayer adsorption of organic molecules on smooth metal oxide surfaces,Q),aluminum oxide layers on evaporated aluminum. These results indicate that a variety of organic molecules with acidic hydrogens, such as carboxylic acids and phenols chemisorb on aluminum Oxide overlayers by proton dissociation - 1 — and that monolayer coverage can be attained quite repro-ducibly by solution doping techniques. - The IETS technique is sensitive to both infrared and Raman modes. — However, almost no examples exist in which Raman il and or infrared spectra have been taken for an adsorbate/substrate system for which IETS spectra have been observed. 

Nearly all theories to date predict that IETS intensities should be proportional to n, the surface density of molecular scatterers. Langan and Hansma (21) used radioactively labeled chemicals to measure a surface concentration vs solution concentration curve ( Fig. 10 ) for benzoic acid on alumina using the liquid doping technique. The dashed line in Fig. 10 is a 2 parameter fit to the data using a simple statistical mechanical model by Cederberg and Kirtley (35). This model matched the free energy of the molecule on the surface with that in solution. The two parameters in this model were the surface density of binding sites ( 10" A )... 

Figure 10. Surface concentration (9) and peak intensities (O) vs. solution concentration using the liquid doping technique for benzoate ions on aluminum (---)...

McBride and Hall (37,38) reported the first observation of a controlled catalytic reaction on alumina using IETS. They studied the catalytically induced transfer hydrogenation from water vapor to unsaturated hydrocarbon chains chemisorbed on alumina at both ends of the chain. They absorbed muconic acid ( trans-trans-1,3 butadiene 1,4 dicarboxylic acid, HOOC-CH=CH-CH=CH-COOH ) onto oxidized aluminum strips using the liquid doping technique. The samples were returned to the vacuum system, and in the presence of 0.3 torr of D2O vapor, heated to up to 400° C by passing current through a heater strip evaporated on the back of the glass slide. The films were then allowed to cool and the junctions completed by evaporation of the Pb counter electrode. 

This section focuses on a-Si H image pickup tubes and presents a-Si H property requirements and fabrication and impurity doping techniques, as well as the structure of photoconductive targets. Pickup tube characteristics that have been attained and some of their applications will be described. 

Seimbille F., Zuddas P., and Michard G. (1998) Granite-hydrothermal interaction a simultaneous estimation of the mineral dissolution rate based on the isotopic doping technique. Earth Planet. Set Lett. 157, 183-191. 

Inclusion in polymer matrices is another way to prepare continuous conducting films. The reticulate doping technique was applied by Laukhina et and Mas-Torrent et to produce organic con-... 

It is certain that electrically conductive polymers have attracted much attention in the field of solid state science in recent years. They are expected to have convenient function in the production of useful electric or electronic devices such as the electrodes in rechargeable batteries, pn-junctions for use in integrated circuits (ICs) or in photovoltaic devices, and so on. In the normal sense, the organic polymers, even the 7r-conju-gated systems having mobile 7r electrons, are typical insulators of poor electrical conductivity and have been utilized as dielectric material. This is considered to be a result of the Peierls transition (Peierls, 1955), namely, a metallic-insulator transition, e.g., for polyacetylene, which is characteristic in the one-dimensional system. This situation is circumvented by the doping technique, in which the electron acceptors or donors... 

Water-soluble ESs can also be prepared by this acid-doping technique. For example, doping of EB with phosphonic acid containing poly(ethyleneglycol)monoethyl ether (PEGME) as a hydrophilic tail gives a mildly conducting PAn that is soluble (or dispersible) in water.161... 

Teramura, K. Wang, Z. Hosokawa, S. Sakata, Y. Tanaka, T. A Doping Technique that Suppresses Undesirable H2 Evolution Derived from Overall Water Splitting in the Highly Selective Photocatalytic Conversion of C02 in and by Water. Chem. Eur. J., 2014, 20, 9906-9909. 

Beck JW, Bemdt ME, Seyfried WE (1992) Application of isotopic doping techniques to evaluate the reaction kinetics and fluid/mineral distribution coefficients An experimental study of calcite at elevated temperatures and pressures. Chem Geol 97 125-144 Beerkens RGC, Waal HD (1990) Mechanisms of oxygen diffusion in glassmelts containing variable-valence ions. J Am Ceram Soc 73 1857-1861... 

Improve processing and doping techniques of Ti-doped sodium alanate which will lower cost. 

Fe-doped glasses and composites were prepared by hybrid sol-gel process, modified in the part of doping technique. The UV-VIS spectra and XRD-investigation show both the presence of oxide and fluoridecomplexes in the glass matrices. 

The direct correlation observed in this study between gloss loss rates and photoinitiation rates suggests that the nitroxide doping technique could provide a rapid test for the evaluation of coating durability. Measurements of nitroxide decay kinetics to determine coating photoinitiation rates can be made at near ambient exposure conditions in a few days (compared to years for... 

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