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Showing 1 to 20 of 46 for “"silanol"”.
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Halfsandwich tungsten complexes with a silanol-functionalized cyclopentadienyl ligand : synthesis and reactivity
Within the studies concerning metallo-silanols, halfsandwich-tungsten complexes have been silanol-functionalized at the cyclopentadienyl ligand. The stability and the condensation behavior have been investigated. Thus, it was shown that these complexes are stable enough for isolation but they are …
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Probing the Hydrogen Bonding Interaction at the Gas-Surface Interface using Dispersion Corrected Density Functional Theory
… surface was approximated using a gas-phase silanol molecule and clusters containing a single hydroxyl moiety. Recent temperature programmed desorption experiments performed in UHV concluded that sulfur mustard and its less toxic mimics undergo molecular adsorption to amorphous silica. …
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Temperature Programmed Desorption and Infrared Spectroscopic Studies of Interfacial Hydrogen Bonds for Small Molecules Adsorbed on Silica and Within Metal Organic Frameworks
… to accept hydrogen bonds from free surface silanol groups. Diethyl sulfide and chlorobutane were investigated to independently assess the roles of the chloro and thioester moieties in the overall adsorption mechanism and to explore the interplay between the charge transfer and electrostatic …
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Studies of the formation of homogeneous mixed silicon-titanium/zirconium oxides by the sol-gel route
… (from 0.56-0.001cm3g-1') and relative number of silanol groups on the surface of the sample above 700°C. Average pore diameters remain constant at temperatures below 900°C (ca 54-21Å for monoliths), although the micropore volume does decrease (0.04-0.0cm3g-1) suggesting that smaller pores are …
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Palladium-Catalyzed Cross-Coupling Reactions of Heteroaryldimethylsilanols: New Methods for the Formation of Substituted Heterocycles Using Preformed and Isolated Silanolates
… of a t-butoxysilyl ether as the masked silanol further expanded the scope of this reaction.
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Silica Dispersion for Applications in Rubber Processing
… molecules. The CA chemically binds to surface silanol groups so that interparticle and particle-polymer interactions are modified in a manner that improves the silica dispersion quality as well as the processability of silica-reinforced rubber composites. However, the control of CA-silica …
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Understanding Functional Silica Additives for HDPE Composite Materials
… were employed in an attempt to quantify the silanol density of the pyrogenic silicas. These techniques were supplemented by the use of <sup>29</sup>Si and <sup>13</sup>C solid state NMR to characterise the functional groups on the surface of the different grades of silica. The estimate of …
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Studies on the Silanol-Based Cross-Coupling Reaction: (1) Development of Methods for the Synthesis of Aryl and Heteroaryldimethysilanols, (2) Expansion of the Substrate Scope of the Cross-Coupling Reaction and (3) Investigations on the Transmetalation of Organosilanols to Transition Metals
… mechanism of transmetalation of alkenyldimethylsilanols a number of molecular traps have been designed, synthesized and subjected to the cross-coupling reaction. A clear preference for formation of the cross-coupling products was observed in these investigations.
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Χημική δομή και μεσοφασικές δράσεις τεσσάρων σιλανιούχων σκευασμάτων επιδιόρθωσης κεραμικών όψεων
… instrument. II) assessement of the activity of silanol -OH groups in the prehydrolyzed materials by Ή-ΡΓ NMR and the D2 0 technique. III) scanning electron microscopy and electron probe microanalysis of the alloy-composite and porcelain-composite repaired interfaces, with intermediate silane …
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Studies of adsorption and stabilization of silica suspensions using well-defined polymeric dispersants
… the carbonyl groups on the polymer and surface silanol groups. The difference in adsorption energies in water and ethanol reflect specific solvent effects that may be related to the formation of hydrogen bond bridges between PEOX and silanol groups in water. Adsorption of PEOX from water, …
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The behavior of water at the modified silica interface.
… surface region by interactions with the surface silanols and the curvature of the silica surface resulted in the observation of a melting peak was that was significantly different than the bulk water behavior. Changes to this peak were observed as a function of the modification of the silica …
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Effects of long-chain surfactants, short-chain alcohols and hydrolyzable cations on the Hydrophobic and Hydration Forces
… of the water molecules H-bonded to the silanol group by methanol, which in turn destroys the water structure in the vicinity of the silica surface. Methanol can displace water from the silanol group because it is more basic than the water. Ethanol, on the other hand, cannot cause the …
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PHOTOCHEMICAL AND TITANIUM (II) MEDIATED METHODS FOR THE SYNTHESIS OF COMPLEX MOLECULAR SCAFFOLDS
… 1,2,5-cyclooctatriene. In the presence of a silanol proton source the allene is converted into a 1,3-diene. Without the combination of silyl 3-enol-1-ynes and silanol, as previously reported with 1,3-enynes, complex mixture of products is observed. Use of more nucleophilic solvents results in …
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Durability and Adhesion of a Model Epoxy Adhesive Bonded to Modified Silicon Substrates
… longer oxygen plasma pretreatment times, more silanol groups may be available to interact with the hydrolyzed silanol groups on silane, resulting in a stronger SCA-Si attachment. Three different tests were employed to determine adhesion and durability of the model epoxy/SCA/SiO2/Si bonded …
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Structure-property behavior of hybrid materials incorporating oligomeric species with inorganic silicates by a sol-gel process
… one of three types of oligomers, which included silanol terminated polydimethylsiloxane (PDMS), triethoxysilane endcapped polytetramethyleneoxide (PTMO), and PTMO with multiple triethoxysilane functional groups. The general reaction scheme was to first generate silanols from both components …
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Supercritical Fluid Chromatography of Ionic Compounds
… into the retention mechanism(s). A fraction of silanol protons were undetected after being treated with the mobile phase which suggested replacement by the cationic component of the additive. CaChe calculations were carried out on several of the additives in an attempt to explain why different …
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Radiation induced degradation of elastomers.
… and chain reformation by condensation of the silanol chain end groups. However,predominant chain reformation was observed during thermal degradation studies and it was believed that this was a consequence of the reformation of chains cut during the test,and also the reformation of chains cut …
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Deactivation and preparation of fused silica open tubular columns for gas and supercritical fluid chromatography
… for cleaning and maximizing the degree of silanol coverage of the surface. The capillary rise method was used to obtain contact angle data for untreated fused silica and fused silica treated with a variety of deactivating reagents. This contact angle data was used in the construction of …
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METHOD DEVELOPMENT FOR THE ANALYSIS OF PROTEINS AND SMALL
… wall, arising from the ionization of surface silanol groups. Presented here is a method for quantitation of protein-dye complexes using a self assembled, surfactant-coated capillary and on-column protein labeling with a non-covalent squarylium dye, Red-1c. Second, seasonal sugar levels are …
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