In–situ Cross–linked Gels as Anti–adhesion Barrier Materials

MEMBRANE ◽  
2015 ◽  
Vol 40 (3) ◽  
pp. 149-154
Author(s):  
Atsushi Shimizu
Keyword(s):  
Adhesion Barrier ◽  
Barrier Materials

Intermetallic Reactions Between Copper and Magnesium as an Adhesion / Barrier Layer

1991 ◽  
Vol 225 ◽  
Author(s):  
Binny Arcot ◽  
C. Cabral ◽  
J. M. E. Harper ◽  
S. P. Murarka
Keyword(s):  
Thin Films ◽  
X Ray Diffraction ◽  
Good Adhesion ◽  
Adhesion Layer ◽  
Adhesion Barrier ◽  
Rich Phase ◽  
Copper Diffusion ◽  
X Ray ◽  
And Diffusion

ABSTRACTThe reliability of copper multilevel interconnections requires good adhesion and the prevention of copper diffusion into the interlevel dielectric. Magnesium is a candidate for an adhesion layer and diffusion barrier for copper due to the high heats of formation of magnesium oxides, fluorides and sulfides and the formation of low resistivity compounds of Mg with copper. An investigation of the interactions in thin films of copper and magnesium has been carried out in the temperature range of 25°C to 500°C. The results of these reactions leading to phase formation in Cu/Mg bilayers deposited on Si3N4 or SiO2 using X-ray diffraction, in situ sheet resistance, and Rutherford backscattering measurements are presented in this paper. It was found that the Mg-rich phase CuMg2 is the first phase to form on annealing to approximately 215°C, followed by the formation of the Cu-rich phase Cu2Mg at about 380°C in the presence of excess Cu.

Oxygen-Induced Inhibition of Noble Metal Silicide Formation: Implications for Electrode/Barrier Structures used with Perovskite Materials

1997 ◽  
Vol 493 ◽  
Author(s):  
K. L. Saenger ◽  
A. Grill ◽  
D. E. Kotecki
Keyword(s):  
Noble Metal ◽  
Metal Electrode ◽  
Inhibitory Effect ◽  
X Ray Diffraction ◽  
X Ray ◽  
Barrier Materials ◽  
Perovskite Materials ◽  
Oxygen Oxygen ◽  
Ambient Oxygen

ABSTRACTWe describe how the inhibitory effect of ambient oxygen on suicide formation may be exploited in designing noble metal electrode structures suitable for perovskite-based memory devices. Reactions of Pt and Ir films with substrates of silicon and tungsten suicide (WSi2.8/Si) were examined after anneals in atmospheric pressure ambients of oxygen or nitrogen al temperatures of 640 °C for various initial noble metal film thicknesses. Metal/silicon reactions and phase formation were studied by Rutherford Backscattering Spectroscopy, X-ray diffraction. and electrical resistance measurements. While annealing in nitrogen resulted in complete noble metal silicidation in the all samples, some Pt and most to all of the Ir remained after equivalent anneals in oxygen. Oxygen exhibited a greater inhibitory effect on silicidation in thin Ir samples, where no suicide formation was observed. The consistent presence of unreacted noble metal M after oxygen annealing is attributed to the formation of an oxygen-containing M-O-Si barrier which interferes with the silicidation reaction. Qualitative through-film resistance measurements indicate that these in-situ formed M-O-Si barrier layers can be at least moderately conductive, a prerequisite for their possible use as a replacement for deposited barrier materials.

Retrieval and Analysis of Simulated Defense HLW Package Experiments at the WIPP

1988 ◽  
Vol 127 ◽  
Author(s):  
Martin A. Molecke ◽  
N. Rob Sorensen
Keyword(s):  
Rock Salt ◽  
Waste Form ◽  
High Level Waste ◽  
General Corrosion ◽  
Uniform Corrosion ◽  
Geochemical Environment ◽  
Waste Package ◽  
Barrier Materials ◽  
Backfill Materials

ABSTRACTIn situ waste package performance experiments involving simulated (non-radioactive) defense high-level waste (DHLW) containers have been in progress since late 1984 at the Waste Isolation Pilot Plant (WIPP) facility. These experiments involve full-size, simulated DHLW containers of several metals and designs emplaced in the WIPP bedded rock salt. These test containers are surrounded by granular backfill (packing) materials, have in many cases been intentionally injected with brines, and are heavily instrumented. A majority of the test packages also contain nonradioactive DHLW borosilicate glass waste form, either within the container and/or outside of it. The primary purpose of these WIPP simulated DHLW experiments is to evaluate the in situ durability and performance of all waste package engineered barrier materials, and to perform package concept validation testing.Twelve of the test DHLW containers, emplaced in WIPP test Room B, have been in heated operation since 1985 and had a maximum surface temperature of about 190°C. These containers were recently retrieved, after about 3 years of heated exposure, for detailed posttest laboratory analyses of: general corrosion and metallurgical degradation, waste form and backfill materials alterations, and other rock salt-brine-barrier materials near-field interactions with the “repository” geochemical environment. Test canisters and overpacks made of ASTM Grade-12 titanium showed essentially no visible degradation in either the base metal or welds; cast mild steel A216/WCA over-packs have suffered some uniform corrosion. Significant degradation of the removed instruments and associated test apparatus has been found: pieces of stainless steel (both 304L and 316) apparatus have undergone extensive stress-corrosion cracking failure and non-uniform attack; Inconel 600-sheathed instruments have undergone both extensive uniform and localized (pitting) attack. Granular backfill materials have been significantly compacted by creep closure to about a density of 2 kg/m. Laboratory analyses are still in progress. Further details on these materials results plus instrumentation data and other in situ WIPP waste package test observations are discussed.

scholarly journals Perspectives of Using Lignin as Additive to Improve the Permeability of In-Situ Soils for Barrier Materials in Landfills

2020 ◽  
Vol 12 (12) ◽  
pp. 5197
Author(s):  
Lucio Di Matteo ◽  
Lorenzo Bulletti ◽  
Eliana Capecchi ◽  
Antonio La Viola ◽  
Davide Piccinino ◽  
...  
Keyword(s):  
Large Scale ◽  
Raw Materials ◽  
Central Italy ◽  
Alluvial Soil ◽  
Barrier Materials ◽  
Organosolv Lignin ◽  
Long Term Performance ◽  
Term Performance ◽  
Sealing Layer

Very often, in-situ soil does not meet the requirements for landfill barriers; therefore, it is necessary to purchase the material from quarries. An increasing number of by-products have been proposed as alternative landfill barrier materials. The present study investigated the performance of two soils of Central Italy (alluvial and volcanic soils) with an organosolv lignin (sulfur-free lignin (SFL)), a widespread by-product in the world. Laboratory investigations indicated that the volcanic soil mixed with 10% in weight of lignin did not reach the permeability value required for landfill bottom liners, also showing high compressibility. On the contrary, the addition of 20% to 30% lignin to the alluvial soil reached the permeability value recommended for the top-sealing layer of landfills: scanning electron microscope analysis indicated that the improvement was due mainly to the physical binding. Large-scale investigations should be carried out to evaluate the long-term performance of the mixtures. The increasing production of organosolv lignin worldwide gives this by-product the opportunity to be used as an additive for the realization of the top-sealing layer. The approach can save the consumption of raw materials (clayey soils from quarries), giving lignin a potential new field of application and recovering in-situ soils.

EVALUATION OF REACTIVE BARRIER MATERIALS FOR IN SITU TREATMENT OF TRICHLOROETHYLENE AND TECHNETIUM-99

2001 ◽  
Vol 2001 (14) ◽  
pp. 530-544
Author(s):  
David L. Freedman ◽  
Lawrence C. Murdoch ◽  
Tanju Karanfil ◽  
Timothy A. DeVol ◽  
Anna Schank ◽  
...  
Keyword(s):  
Barrier Materials ◽  
Reactive Barrier

Evaluation of peat and sawdust as permeable reactive barrier materials for stimulating in situ biodegradation of trichloroethene

2016 ◽  
Vol 313 ◽  
pp. 37-48 ◽  
Author(s):  
Pulin K. Mondal ◽  
Glaucia Lima ◽  
David Zhang ◽  
Line Lomheim ◽  
Robert W. Tossell ◽  
...  
Keyword(s):  
Permeable Reactive Barrier ◽  
Barrier Materials ◽  
Reactive Barrier ◽  
In Situ Biodegradation

A review of analogues of alkaline alteration with regard to long-term barrier performance

2011 ◽  
Vol 75 (4) ◽  
pp. 2401-2418 ◽  
Author(s):  
D. Savage
Keyword(s):  
Mineral Dissolution ◽  
Time Intervals ◽  
Barrier Materials ◽  
Disturbed Zone ◽  
Natural Analogues ◽  
Zeolite Formation ◽  
Hydraulic Gradients ◽  
Short Time

AbstractCement and concrete will be used as fracture grouts, shotcrete, tunnel and borehole seals, and as matrices for waste encapsulationinter aliain geological repositories for radioactive wastes. Alteration of the host rock and/or swelling clay in waste package buffers and tunnel backfills by hyperalkaline solutions from cement/concrete may be deleterious to system performance through changes in the physicochemical properties of these barrier materials.Analogue systems (and timescales) relevant to the understanding of the alkaline disturbed zone include: industrial analogues, such as alkaline flooding of hydrocarbon reservoirs (up to 30 y), cement-aggregate reactions (up to 100 y) and the Tournemire tunnel (up to 125 y); and natural analogues, including the hyperalkaline springs at Maqarin, Jordan (more than 100,000 y), saline, alkaline lakes (more than 1,000,000 y) and certain fracture fillings in granites (more than 1,000,000 y).These systems show that alkaline alteration can be observed for thousands of years over distance scales of hundreds of metres under extreme conditions of hydraulic gradients in fractured rocks (Maqarin), but may be limited to a few centimetres over tens to a hundred years in mudstone (Tournemire). Important reaction mechanisms for retardation of alkaline fluids include: fluid mixing (alkaline oil floods, Maqarin), ion exchange (alkaline oil floods, Tournemire) and kinetic mineral dissolution-precipitation reactions (all systems studied). Qualitative and quantitative kinetic data for mineral reactions are available from cement aggregate reactions and the Searles Lake analogue, respectively. Short-term alteration observed in cement-aggregates is characterized by calcium silicate hydrate (C-S-H) minerals and incipient zeolite formation, whereas evidence from the Tournemire tunnel shows the growth of K-feldspar after relatively short time intervals (tens to a hundred years). There is a tendency for alkaline alteration to result in porosity decreases, but locally, porosity may be enhanced (e.g. near-injection well interactions in alkaline oil floods, or at fracture margins at Maqarin, Jordan). Data from industrial and natural analogues may thus supply some key data for bridging time and space scales between laboratory andin situexperiments on one hand and the requirements for safety assessment on the other.

scholarly journals Assessing the mobility of clay materials used in the construction of engineered safety barriers for radioactive waste disposal

2021 ◽  
Vol 16 (3) ◽  
pp. 51-60
Author(s):  
S. G. Maryinskikh ◽  
◽  
V. V. Zhigarev ◽  
O. A. Ilyina ◽  
V. V. Krupskaya ◽  
...  
Keyword(s):  
Large Scale ◽  
Production Control ◽  
Radioactive Waste Disposal ◽  
Near Surface ◽  
Barrier Materials ◽  
Safety Barriers ◽  
Materials Used ◽  
Near Future

Large-scale efforts implemented under the Unified State System for RW Management including the construction of near-surface disposal facilities for RW Class 3 and 4, as well as provision of long-term safety at nuclear legacy facilities require the scientific community to develop systems of engineered safety barriers preventing radionuclide releases into the environment. In the near future, at least 70 storage facilities for non-retrievable RW will require the installation of such barrier systems. The quality of barrier materials constituting to the system of engineered safety barriers (EBS), including their ability of providing a uniform backfilling of cavities inside the structures, is viewed as an important design parameter requiring proper assessment both under the production control of materials and quality control of designed EBS, including relevant in situ testing.

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