Aqueous silane solution

When the treatment times for silane application were varied up to 30 min immersion of the fibers in 0.5% aqueous silane solution, it was found that the... 

From the work of Pratt and co-workers and analysis of the available literature, a reasonable model for hydrolysis mechanisms can be developed. The studies of the hydrolysis of mono-, di-, and trifunctional silane esters in aqueous and aqueous-organic solutions lead to a kinetic expression describing the rate of silane ester disappearance (hydrolysis) ... 

To a solution of copper chloride (2.4 mg, 0.024 mmol) in DMF (1.5 ml) was added l-chloro-2-phenylacetylene (50 mg, 0.37 mmol) at r.t. To the mixture was added trimethyl(4-methoxyphenylethynyl)silane (50 mg, 0.25 mmol). The reaction mixture was stirred for 48 h at 80 °C, quenched with 3 M HCl, and extracted with diethyl ether (25 ml x 2). The combined ethereal layer was washed with aqueous NaHCOj solution, then with brine and dried over MgS04. Filtration and evaporation provided a brown oil. Purification by column chromatography (Si02, hexane dichloromethane = 10 1) gave l-(4-methoxyphenyl)-4-phenyl-1,3-butadiyne (36 mg, 65% yield) as a colorless solid. 

To a suspension of KF (spray dried, 2.1 g, 36 mmol) in DMF (7.0 ml) was added 1.7 g (7.2 mmol) of (dichloro)(ethyl)(4-methoxyphenyl)silane and 4-trifluoro-1-bromobenzene (1.05 g, 6.0 mmol) at 0°C under an argon atmosphere. The resulting reaction mixture was then stirred at 60 °C for 3 h. The mixture was allowed to cool to r.t., and a solution of palladium acetate (6.7 mg, 0.030 mmol) and triphenylphosphine (7.8 mg, 0.030 mmol) in DMF was added. The reaction mixture was heated at 120 °C for 18 h and then cooled to r.t., poured into a saturated aqueous NaCl solution, and extracted with ethyl acetate (20 ml x 3). The combined organic extracts were dried over MgS04. Concentration under... 

In most cases the silane is applied to the filler neat or in diluted form. Typically the silane or silane solution is sprayed onto the filler as it is being agitated. Most important commercial silane coating processes are continuous, with high throughput rates, but application may also be performed in batches. Control of silane addition, dwell time, and temperature within the system is essential for a suceessful coating. Evolution of volatiles (VOC) must be monitored. To remove reaction byproducts, solvents, and water, and to bond the silane to the filler surface, further heat treatment may be necessary. For those fillers typically processed as a slurry, aqueous treatment with waterborne silanes is also possible. 

An aqueous 2 % silane solution (from stock solution of 50 % silane in methanol) was stirred for 15 min and filtered through a 0.2 pm PTFE filter. The substrates were immersed for 30 min, then... 

In FRP products, the silanes are usually applied to the fibers from an aqueous solution. Earlier studies carried out in our laboratory (2) indicated a strong dependence of composite mechanical properties on the concentration of silane in the coating solution, as well as on the silane organofunctionality. Our investigations focus on the effect of silane solution concentration and functionality on the nature and properties of silane coatings deposited from such solutions. Fourier transform infrared... 

In model studies of silane coatings, the as-received silanes were dissolved in aqueous solution and acidified with acetic acid to pH=3.5. Equal volumes of silane solution were then poured into teflon-coated aluminum dishes. The silane precipitated upon heating and was dried... 

Silane solution Figure 8.28 Schematic illustration of multistream laminar flows for selective patterning of channel walls and the corresponding image of aqueous flow inside channels after surface patterning. From [162],... 

Early synthetic procedures for preparing glass for affinity chromatography or enzyme immobilization involved refluxing y-aminopropyltriethoxysilane with the beads (17) under various conditions the beads were coated with multiple layers of silane, which were not as stable as desired. A more stable layer is obtained by employing aqueous silanization at pH 3.75 and 75°C (17). Nonetheless, aminoalkyl glass, or any other silanized glass material, is unstable in aqueous solution at pH values much above 7. Similar materials prepared from zirconium oxides are, conversely, stable in base and labile in acid. 

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