scholarly journals Adsorption properties of iodine on fused silica surfaces when evaporated from tellurium in various atmospheres

2020 ◽  
Vol 326 (1) ◽  
pp. 711-718
Author(s):  
Erik Karlsson ◽  
Jörg Neuhausen ◽  
Robert Eichler ◽  
Alexander Vögele ◽  
Andreas Türler
Keyword(s):  
Silica Surface ◽  
Single Species ◽  
Production Method ◽  
Fused Silica ◽  
Adsorption Enthalpy ◽  
Silica Surfaces ◽  
Carrier Free ◽  
Free Iodine ◽  
Chemical Conditions ◽  
Iodine Oxides

Abstract The evaporation of iodine containing species from tellurium has been investigated together with their adsorption behavior on a fused silica surface. In inert gas, the formation of two species was observed with adsorption enthalpies of around − 90 to − 100 and − 110 to − 120 kJ/mol, respectively. For reducing environments, a single species identified as monatomic iodine was observed with an adsorption enthalpy around − 95 kJ/mol. In oxidizing conditions, species with low adsorption enthalpies ranging from − 65 to − 80 kJ/mol were observed. Presumably, these are iodine oxides as well as oxo-acids of iodine (HIOx). The results of the thermochromatography experiments performed here prove the usefulness of the employed production method for carrier-free iodine isotopes and enhance the understanding of the evaporation and deposition behavior of iodine under various chemical conditions.

Investigations on adsorption and transport behaviour of carrier-free silver, gold and platinum in quartz columns under vacuum conditions

2004 ◽  
Vol 92 (8) ◽  
Author(s):  
Alexander Hohn ◽  
R. Eichler ◽  
B. Eichler
Keyword(s):  
Monte Carlo ◽  
Thermodynamic Model ◽  
Fused Silica ◽  
Spallation Neutron Source ◽  
Adsorption Enthalpy ◽  
Silica Surfaces ◽  
Carrier Free ◽  
Transport Behaviour ◽  
Cadmium Lead ◽  
Good Agreement

SummaryThe adsorption enthalpy of silver and gold atoms on fused silica surfaces was measured using vacuum-thermochromatography. Carrier-free silver, gold and platinum nuclides were produced by irradiation of cadmium, lead and mercury targets at the Swiss Spallation Neutron Source SINQ, followed by a thermochromatographic separation. For the calculation of the adsorption enthalpy from experimental data a thermodynamic model and a kinetic model (Monte Carlo simulation) were used. Our measurements revealed an adsorption enthalpy of -279±10 kJ/mol for gold, -232±13 kJ/mol for silver and an upper limit of -430 kJ/mol for platinum. These values, determined by the thermodynamic model, are in good agreement with literature values based on the same model. Additionally, Monte Carlo simulations have been performed to demonstrate the influence of temperature and size of quartz columns on the transport of model-isotopes with different half-lives.

scholarly journals Thermochromatographic behavior of iodine in fused silica columns when evaporated from lead–bismuth eutectic

2020 ◽  
Vol 326 (2) ◽  
pp. 1249-1258
Author(s):  
Erik Karlsson ◽  
Jörg Neuhausen ◽  
Robert Eichler ◽  
Alexander Aerts ◽  
Ivan I. Danilov ◽  
...  
Keyword(s):  
Single Species ◽  
Reactor Design ◽  
Fused Silica ◽  
Empirical Correlation ◽  
Adsorption Enthalpy ◽  
Deposition Behavior ◽  
Iodine Species ◽  
Fundamental Understanding ◽  
Lead Bismuth Eutectic ◽  
Carrier Gases

Abstract As a step toward licensing a lead–bismuth eutectic (LBE) based reactor design, the adsorption behavior of iodine evaporated from LBE on fused silica was examined. Using inert and reducing carrier gases, depositions with an adsorption enthalpy of − 95 to − 113 kJ mol−1 were observed. These depositions are compatible with a single species, tentatively identified as bismuth monoiodide, BiI. When introducing oxidizing conditions, multiple iodine species with higher volatility form, with adsorption enthalpies ranging from − 67 to − 86 kJ mol−1. Based on an empirical correlation one of these species was identified as monatomic iodine. This work provides fundamental understanding of the LBE/iodine gaseous chemistry and related adsorption deposition behavior.

A recycling strategy of ion beam removal and recoating of sol-gel film on fused silica surface

Optik ◽  
2021 ◽  
pp. 167259
Author(s):  
Wenfeng Sun ◽  
Xia Xiang ◽  
Bo Li ◽  
Xiang Dong ◽  
Xiaolong Jiang ◽  
...  
Keyword(s):  
Silica Surface ◽  
Ion Beam ◽  
Sol Gel ◽  
Fused Silica ◽  
Gel Film

scholarly journals Quantification of Carbonic Contamination of Fused Silica Surfaces at Different Stages of Classical Optics Manufacturing

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1620
Author(s):  
Robert Köhler ◽  
Domenico Hellrung ◽  
Daniel Tasche ◽  
Christoph Gerhard
Keyword(s):  
Chemical Composition ◽  
Photoelectron Spectroscopy ◽  
Decisive Role ◽  
Fused Silica ◽  
Process Step ◽  
Carbon Contamination ◽  
Silica Surfaces ◽  
Carbon Impurities ◽  
High Level ◽  
Glass Surfaces

The chemical composition of ground and polished fused silica glass surfaces plays a decisive role in different applications of optics. In particular, a high level of carbon impurities is often undesirable for further processing and especially for gluing or cementing where adhesion failure may be attributed to carbonic surface-adherent contaminants. In this study, the surface carbon content at different stages of classical optics manufacturing was thus investigated. Two different standard processes—grinding and lapping with two final polishing processes using both polyurethane and pitch pads—were considered. After each process step, the chemical composition and roughness of the surface were analysed using X-ray photoelectron spectroscopy and atomic force microscopy. An obvious correlation between surface roughness and effective surface area, respectively, and the proportion of carbon contamination was observed. The lowest carbon contamination was found in case of lapped and pitch polished surfaces.

scholarly journals Monitoring annealing via CO_2 laser heating of defect populations on fused silica surfaces using photoluminescence microscopy

2010 ◽  
Vol 18 (14) ◽  
pp. 15207 ◽  
Author(s):  
Rajesh N. Raman ◽  
Manyalibo J. Matthews ◽  
John J. Adams ◽  
Stavros G. Demos
Keyword(s):  
Laser Heating ◽  
Fused Silica ◽  
Silica Surfaces ◽  
Photoluminescence Microscopy

Influence of secondary treatment with CO 2 laser irradiation for mitigation site on fused silica surface

2016 ◽  
Vol 25 (10) ◽  
pp. 108104
Author(s):  
Yong Jiang ◽  
Qiang Zhou ◽  
Rong Qiu ◽  
Xiang Gao ◽  
Hui-Li Wang ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Silica Surface ◽  
Fused Silica ◽  
Secondary Treatment

scholarly journals Labeling of Salmonella Typhymurium with iodine-131 to study phagocytic function in rats

1989 ◽  
Vol 31 (3) ◽  
pp. 135-138
Author(s):  
Maria K. Sato ◽  
Aldo J. Rodrigues Junior ◽  
Edwaldo E. Camargo
Keyword(s):  
Whole Body ◽  
Large Field ◽  
Scintillation Camera ◽  
Functional Evaluation ◽  
Body Images ◽  
System A ◽  
Carrier Free ◽  
Free Iodine ◽  
Iodine 131 ◽  
Reticulo Endothelial System

The present study describes a method for labeling Salmonella typhymurium with iodine-131 to evaluate both the morphological and the functional characteristics of the reticulo-endothelial system. A suspension containing 2 x 10(9) bacteria per ml was labeled with carrier-free Na131I without reductor, with a labeling yield of 46.5 ± 3% and 3.5 ± 1.3% of free Iodine-131. The biodistribution of the labeled bacteria in rats was studied with a large field-of-view scintillation camera equiped with a pinhole collimator. Whole body images were obtained 15 and 30 minutes after intravenous injection of the labeled microorganisms. Images showed accumulation of bacteria in the liver and both normal and transplanted spleens of the animals. Autoradiographs of liver and spleen demonstrated labeled bacteria within the cells of the reticulo-endothelial system. The method described is easy to perform, has a good labeling yield and allows the functional evaluation of the reticulo-monophagocytic system, including transplanted spleens.

Determination of the Orientation of Silanes on Silica Surfaces by Fourier Transform Infrared Photoacoustic Spectroscopy

1986 ◽  
Vol 40 (4) ◽  
pp. 513-519 ◽  
Author(s):  
Marek W. Urban ◽  
Jack L. Koenig
Keyword(s):  
Fourier Transform ◽  
Photoacoustic Spectroscopy ◽  
Surface Coverage ◽  
Silica Surface ◽  
Fourier Transform Infrared ◽  
Coupling Agents ◽  
Surface Hydroxyl ◽  
Silica Surfaces ◽  
Quantitative Surface Analysis ◽  
Infrared Photoacoustic Spectroscopy

Fourier transform infrared photoacoustic spectroscopy has been used for quantitative surface analysis of silica treated with trifunctional coupling agents such as γ-Methacryloxypropyltriethoxysilane (γ-MPS), γ-Glycidoxypropyltrimethoxysilane (γ-GPS), and γ-Aminopropyltri-ethoxysilane (γ-APS). The calibration curves are obtained for several characteristic bands of the coupling agents. Using a highly polarizable gas in the photoacoustic cell and comparing the spectra with a nonpolarizable coupling gas, it is possible to evaluate orientation of the coupling agents on the silica surface. The type of orientation is a function of the extent of surface coverage. At low surface coverage, coupling agents tend to take a perpendicular orientation with respect to the surface, and increasing surface coverage leads to parallel orientation. Increasing the coupling agent concentration also causes orientational changes of the species which form chemical bonds with the silica surface (hydroxyl, water, and carbonyl groups).

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