Adhesion of Hydrated Silicate Films

1988 ◽  
Vol 121 ◽  
Author(s):  
Terry A. Michalské ◽  
Keith D. Keefer
Keyword(s):  
Silica Glass ◽  
Room Temperature ◽  
Surface Composition ◽  
Adsorbed Water ◽  
Adhesive Bond ◽  
Silicate Solution ◽  
Heat Treatments ◽  
Hydrated Silicate ◽  
Surface Oxygen Groups ◽  
Oxygen Groups

ABSTRACTWe used fracture mechanics test techniques to measure the adhesive bond energy formed between hydrated silica glass surfaces and silicate species deposited from solution. In the case of silicate surfaces hydrated in room temperature water vapor, intermolecular bonding between hydrated surfaces can be attributed to either hydrogen bonding interactions between adsorbed water molecules (0.15 J/m2) or electrostatic bonds formed between adsorbed cations and anionie-nonbridging surface oxygen groups (2.0 J/m2). The bonding interaction observed at room temperature depends upon the glass surface composition and the degree of surface hydration. When hydrated silicate solution species are added to the interface and heat treated, adhesion energies as large as the cohesive energy of silica glass can be obtained with heat treatments as low as 200 C. The adhesion of the silicate interfacial film produced by the addition of solution species is greatest for silicate precursors showing a low degree of molecular crosslinking. In addition, the presence of alkali in the silicate solution greatly enhances interface adhesion for heat treatments below 200 C.

scholarly journals Tailoring Properties of Resol Resin-Derived Spherical Carbons for Adsorption of Phenol from Aqueous Solution

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1736
Author(s):  
Karol Sidor ◽  
Tomasz Berniak ◽  
Piotr Łątka ◽  
Anna Rokicińska ◽  
Marek Michalik ◽  
...  
Keyword(s):  
Surface Composition ◽  
Micropore Volume ◽  
Gaseous Ammonia ◽  
Poly Vinyl Alcohol ◽  
Clear Correlation ◽  
Hno3 Solution ◽  
Synthesis Conditions ◽  
Adsorption Of Nitrogen ◽  
Oxygen Groups ◽  
Size Of Particles

The polycondensation of resorcinol and formaldehyde in a water–ethanol mixture using the adapted Stöber method was used to obtain resol resins. An optimization of synthesis conditions and the use of an appropriate stabilizer (e.g., poly(vinyl alcohol)) resulted in spherical grains. The resins were carbonized in the temperature range of 600–1050 °C and then chemically activated in an aqueous HNO3 solution, gaseous ammonia, or by an oxidation–reduction cycle (soaking in a HNO3 solution followed by treatment with NH3). The obtained carbons were characterized by XRD, the low-temperature adsorption of nitrogen, SEM, TGA, and XPS in order to determine degree of graphitization, porosity, shape and size of particles, and surface composition, respectively. Finally, the materials were tested in phenol adsorption. The pseudo-second order model perfectly described the adsorption kinetics. A clear correlation between the micropore volume and the adsorption capacity was found. The content of graphite domains also had a positive effect on the adsorption properties. On the other hand, the presence of heteroatoms, especially oxygen groups, resulted in the clogging of the pores and a decrease in the amount of adsorbed phenol.

Influence of Heat Treatment on Microstructure and Mechanical Properties of Selective Laser Melted TiAl6V4 Alloy

2018 ◽  
Vol 284 ◽  
pp. 615-620 ◽  
Author(s):  
R.M. Baitimerov ◽  
P.A. Lykov ◽  
L.V. Radionova
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Selective Laser Melting ◽  
Room Temperature ◽  
Base Alloy ◽  
Tensile Tests ◽  
Heat Treatments ◽  
Laser Melting ◽  
Microstructure And Mechanical Properties ◽  
Treatment Procedures

TiAl6V4 titanium base alloy is widely used in aerospace and medical industries. Specimens for tensile tests from TiAl6V4 with porosity less than 0.5% was fabricated by selective laser melting (SLM). Specimens were treated using two heat treatment procedures, third batch of specimens was tested in as-fabricated statement after machining. Tensile tests were carried out at room temperature. Microstructure and mechanical properties of SLM fabricated TiAl6V4 after different heat treatments were investigated.

Water isotherms of activated carbons with small amounts of surface oxygen groups: fitting the mesopore region

Carbon ◽  
2001 ◽  
Vol 39 (2) ◽  
pp. 309-310 ◽  
Author(s):  
P Lodewyckx ◽  
D Van Rompaey ◽  
L Verhoeven ◽  
E.F Vansant
Keyword(s):  
Activated Carbons ◽  
Surface Oxygen ◽  
Surface Oxygen Groups ◽  
Oxygen Groups

Contribution of surface oxygen groups to the measured capacitance of porous carbon supercapacitors

2018 ◽  
Vol 395 ◽  
pp. 271-279 ◽  
Author(s):  
Jocelyn E. Zuliani ◽  
Shitang Tong ◽  
Charles Q. Jia ◽  
Donald W. Kirk
Keyword(s):  
Porous Carbon ◽  
Surface Oxygen ◽  
Surface Oxygen Groups ◽  
Oxygen Groups ◽  
Carbon Supercapacitors

Change of sign in the Casimir interaction of peptide films deposited on a dielectric substrate

2020 ◽  
Vol 35 (03) ◽  
pp. 2040020 ◽  
Author(s):  
E. N. Velichko ◽  
M. A. Baranov ◽  
V. M. Mostepanenko
Keyword(s):  
Free Energy ◽  
Film Thickness ◽  
Silica Glass ◽  
Room Temperature ◽  
Glass Plate ◽  
Pressure Change ◽  
Dielectric Substrate ◽  
Numerical Computations ◽  
Peptide Coatings

The Casimir free energy and pressure of thin peptide films deposited on a dielectric substrate are investigated in the region of parameters where they change their sign. Numerical computations are performed for a modelled peptide film on a silica glass plate. The Casimir free energy is computed at room temperature as a function of the film thickness and the fraction of water contained in the film. It is shown that the values of the Casimir pressure change from negative to positive when the film thickness decreases to below some value in the region from 115 to 133 nm depending on the fraction of water in the film. Possible applications of the obtained results to the problem of stability of peptide coatings are discussed.

Investigation of Ageing Phenomena in CuAlNi Based Shape Memory Alloys

2007 ◽  
Vol 537-538 ◽  
pp. 129-136 ◽  
Author(s):  
Marton Benke ◽  
Valéria Mertinger ◽  
E. Nagy ◽  
Jan Van Humbeeck
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Ternary Alloy ◽  
Room Temperature ◽  
Beta Phase ◽  
Heat Treatments ◽  
Thermoelastic Martensitic Transformation ◽  
Transformation Temperatures ◽  
Exothermic Process

The ageing phenomena and its effect on the thermoelastic martensitic transformation was investigated in three Cu-base SMAs. The transformation temperatures shifted to higher temperatures due to aging in the beta-phase. To increase the alloy’s ductility, a definite amount of Mn (4 wt%) and Fe (2 wt%) were added to the ternary alloy. The thermoelastic martensitic transformation was found in the not-aged samples of the CuAlNiMn and CuAlNiMnFe alloys. This transformation was destroyed due to ageing heat treatments by a fairly unknown exothermic process. The thermoelastic martensitic transformation appeared again in the aged CuAlNiMn and CuAlNiMnFe samples after keeping them on room temperature for a few months. This phenomena was investigated by DSC, SEM, TEM, and XRD.

Catalytic properties of a Rh–diamine complex anchored on activated carbon: Effect of different surface oxygen groups

2007 ◽  
Vol 331 ◽  
pp. 26-33 ◽  
Author(s):  
L.J. Lemus-Yegres ◽  
I. Such-Basáñez ◽  
M.C. Román-Martínez ◽  
C. Salinas-Martínez de Lecea
Keyword(s):  
Activated Carbon ◽  
Catalytic Properties ◽  
Surface Oxygen ◽  
Surface Oxygen Groups ◽  
Oxygen Groups

An investigation on microstructure and mechanical properties of post-weld heat-treated friction stir welds in aluminum alloy 2024-W

2012 ◽  
Vol 227 (4) ◽  
pp. 649-662 ◽  
Author(s):  
Hakan Aydın ◽  
Ali Bayram ◽  
İsmail Durgun
Keyword(s):  
Room Temperature ◽  
Welded Joint ◽  
Solution Treatment ◽  
Heat Treatments ◽  
Maximum Hardness ◽  
Friction Stir ◽  
Base Materials ◽  
Heat Treated ◽  
Aluminum Alloy 2024 ◽  
Weld Heat

The present work describes the results obtained from microstructural and mechanical evaluation of post-weld heat treated friction stir welds of 2024 aluminum alloys in the W temper state. Post-weld heat treatments have been carried out at 510 °C for 2.5 h followed by ageing at room temperature for 6 months, at 100 °C and 190 °C for 10 h, and by cooling in static air (O-temper). The solution treatment caused abnormal coarsening of the grains in the stir zone, which resulted in a drop in microhardness. The strength of the as-welded joint was significantly incrased by post weld heat treatments. The maximum hardness and strength values were obtained in T6 (190 °C, 10 h) treated joint. However, the T6 (190 °C, 10 h) treated joint had the lowest ductility. On the other hand, the tensile properties of the post-weld heat treated joints were far lower than those of the unwelded base materials in the same temper states. In addition, the post-weld heat treatments did not significantly change the fracture locations of the friction stir welds.

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