Search results
Results from the WOW.Com Content Network
This is undesirable because most paints undergo chemical reactions during the process of curing (for example, latex- and alkyd-based paints polymerise when curing) which is dependent on the water or solvent evaporating slowly. A layer of primer will prevent the underlying wood from prematurely absorbing the solvents in the finishing paint.
To offset this reaction and prepare samples for analysis, "target areas are exposed mechanically and prepared for color matching. Samples are then light bleached for two weeks under a fluorescent tube to reverse darkening and yellowing of linseed oil. Samples are then measured with a chromameter.
As in many chemical reactions, chemiluminescence starts with the combining of two compounds, say A and B, to give a product C. Unlike most chemical reactions, the product C converts to a further product, which is produced in an electronically excited state often indicated with an asterisk: A + B → C C → D*
Slow motion videos are great with extreme sports and hilarious effects of pranks, but this technology can also turn plain chemical reactions into beautiful art. The project Beautiful Chemistry ...
A chemical (typically a solvent) can be sprayed along with the paint to dissolve together both the delivered paint and the chemicals on the surface of the object being painted; Some chemical reactions in paint involve the orientation of the paint molecules. Expression [clarification needed]
Whitewash is especially compatible with masonry because it is absorbed easily and the resultant chemical reaction hardens the medium. [citation needed] Lime wash is pure slaked lime in water. It produces a unique surface glow due to the double refraction of calcite crystals. Limewash and whitewash both cure to become the same material.
A drying oil is an oil that hardens to a tough, solid film after a period of exposure to air, at room temperature. The oil hardens through a chemical reaction in which the components crosslink (and hence, polymerize) by the action of oxygen (not through the evaporation of water or other solvents).
Pentaerythritol was first reported in 1891 by German chemist Bernhard Tollens and his student P. Wigand. [5] It may be prepared via a base-catalyzed multiple-addition reaction between acetaldehyde and 3 equivalents of formaldehyde to give pentaerythrose (CAS: 3818-32-4), followed by a Cannizzaro reaction with a fourth equivalent of formaldehyde to give the final product plus formate ion.