Spatula, silicone

I have a few sizes of silicone spatulas on hand for different purposes. Smaller spatulas are great for stirring chocolate in a double boiler, and larger ones are useful for scraping down the sides of the mixing bowl when making frostings or batters. 

Use a wooden spoon or a heatproof silicone spatula to turn the eggs over gently as they cook (infrequently, so you re not touching them too much), pulling a track through the eggs as they set so that more uncooked egg touches the pan. 

Chemical Analysis. The presence of silicones in a sample can be ascertained qualitatively by burning a small amount of the sample on the tip of a spatula. Silicones bum with a characteristic spaddy flame and emit a white sooty smoke on combustion. A white ashen residue is often deposited as well. If this residue dissolves and becomes volatile when heated with hydrofluoric acid, it is most likely a siliceous residue (437). Quantitative measurement of total silicon in a sample is often accomplished indirectly, by converting the species to silica or silicate, followed by determination of the heteropoly blue siUcomolybdate, which absorbs at 800 nm, using atomic spectroscopy or uv spectroscopy (438—443). Pyrolysis gc followed by mass spectroscopic detection of the pyrolysate is a particularly sensitive tool for identifying silicones (442,443). This techmque relies on the pyrolytic conversion of silicones to cyclics, predominantly to [541-05-9] which is readily detected and quantified (eq. 37). 

Diphenyllead diazide is obtained from the reaction mixture in the form of very small needle-like crystals. No suitable recrystallizing solvent could be found. Diphenyllead diazide is insoluble in water, 95% ethanol, and anhydrous diethyl ether. Insertion of 2 mg. of substance on the tip of a porcelain spatula into an open flame results in immediate ignition, and burning proceeds with a crackling sound accompanied by flashes of light. A deposit of metallic lead remains when the spatula is cooled. Observation of the thermal characteristics of diphenyllead diazide under silicone oil on a Fisher-Johns block (heating at 5 to... 

Using a spatula, a crystal was removed from a flask containing a silicon-nitrogen compound and mounted onto the diffractometer. This crystal was the only one to be found in the flask. The space group was determined to be PI with half a molecule per asymmetric unit. The model from SHELXS shows a silicon atom and several other electron density maxima. Ten of those maxima form a familiar shape a Cp ligand, and can be assigned the atom type carbon. The model in file si-01.ins on the accompanying CD-ROM reflects this interpretation of the solution. 

Free-flowing RTV-2 silicone rubbers are, after deaeration, just poured over the model, whereas spreadable and non-sag compounds are applied using a spatula. Kneadable grades in the form of a sheet are pressed on the model surface by hand or using a roller. 

The molecules pentaerythritol tetranitrate (PETN, 2) and its silicon analogue (Si-PETN, 3) provide a striking example of the consequences that can follow from a 1,3 intramolecular interaction [37]. PETN is a well known explosive, quite sensitive to impact dropping a 2.5 kg mass upon it from a height of just 14 cm has a 50% probability of producing detonation [62]. However Si-PETN, prepared only recently [63], is reported to be so remarkably more sensitive that impact is not even needed touching with a spatula is sufficient to cause explosion ... 

Uses of Silicone Rubbers. Becanse of their high cosL silicone elastomers are used only in applications where other elastomers fail. They are mainly nsed in applications requiring high heat resistance and extreme low-temperature flexibility. These elastomers are used in the electricaL electronic, aerospace, antomotive, mechanical equipment, fighting, cable, and textile indnstries. They are also nsed in pharmacentical and medical applications for components in contact with food. They are now nsed in high-temperature cooking utensils (e.g., scrapers and spatulas). 

The typical lengths of the MWCNTs are approximately 65/tm and have a diameter of 10-20 nm. The MWCNTs are then embedded and stabilised in a poly (methyl methacrylate) (PMMA) matrix. This matrix is then peeled off the silicon to form a very smooth surface, which is etched with a good solvent, typically acetone, to produce brushes of MWNTs, analogous to the spatula of the... 

A 1 g sample is dissolved in 10 ml sodium hydroxide solution (25 g/100 ml) and 10 ml water in a 250 ml quartz beaker, under addition of 2 to 3 spatula tips of sodium peroxide. After dissolution, 30 ml sulfuric acid (1+1) are added under stirring and the solution is warmed up until it clarifies. To separate any silicon which may be present, the solution is boiled down until fuming starts. After cooling, the residue is taken up with hot water, heated until the sulphates dissolve, filtered into a 250 ml quartz beaker and washed twice or thrice with hot water. The filter is then ashed in a platinum crucible and the silicon volatilized by fuming with 2 drops sulphuric acid (1+1) and 2 ml hydrofluoric acid (40 %). The fuming residue is dissolved with 4 drops of sulphuric acid (d = 1.84) and a little water and the solution added to the filtrate. After boiling down the filtrate is made up to 100 ml in a quartz measuring flask. 10 ml sulphuric acid... 

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