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Although they are attracted to oil, and an oil-in-water emulsion forms, the emulsion will not stay stable for long and will eventually coalesce. [10] With the addition of a polyelectrolyte, electrostatic forces between the oil and water interface are formed and the surfactant begins to act as an “anchor” for the polyelectrolyte, stabilizing ...
Photographic emulsion is a light-sensitive colloid used in film-based photography. Most commonly, in silver-gelatin photography , it consists of silver halide crystals dispersed in gelatin . The emulsion is usually coated onto a substrate of glass , films (of cellulose nitrate , cellulose acetate or polyester ), paper, or fabric.
To dust the emulsion side, it is best to use an unused paint brush and, very gently, brush from the center to the outside of the plate. To clean the underside of the leaf (non-emulsion side), dip a cotton ball or cotton round into a cup of distilled water, and work from the middle of the plate to the outside. Water on the emulsion side will ...
A black and white photographic print in a tray while being processed after exposure to light under a photographic enlarger. Typically three trays are used containing either developer, stop bath, or fixer, in that order.
Creaming, in the laboratory sense, is the migration of the dispersed phase of an emulsion under the influence of buoyancy.The particles float upwards or sink depending on how large they are and density compared to the continuous phase as well as how viscous or how thixotropic the continuous phase might be.
Film is then dried in a dust-free environment, cut and placed into protective sleeves. Once the film is processed, it is then referred to as a negative. The negative may now be printed; the negative is placed in an enlarger and projected onto a sheet of photographic paper. Many different techniques can be used during the enlargement process.
Cellulose diacetate film was first created by the German chemists Arthur Eichengrün and Theodore Becker, who patented it under the name Cellit, from a process they devised in 1901 for the direct acetylation of cellulose at a low temperature to prevent its degradation, which permitted the degree of acetylation to be controlled, thereby avoiding total conversion to its triacetate.
It was invented by French scientist Gabriel Lippmann in 1891 and consists of first focusing an image onto a light-sensitive plate, placing the emulsion in contact with a mirror (originally liquid mercury) during the exposure to introduce interference, chemically developing the plate, inverting the plate and painting the glass black, and finally ...