Therefore potassium dichromate cannot be used as mordant effectively.

It is also used as a mordant ( i. e., a fixing agent ) for dyes in fabric.

The dye is generally applied in an aqueous solution, and requires a mordant to improve the fastness of the dye on the fiber.

The choice of mordant is very important as different mordants can change the final color significantly.

Most natural dyes are mordant dyes and there is therefore a large literature base describing dyeing techniques.

Food dyes can be direct, mordant and vat dyes, and their use is strictly controlled by legislation.

Etching is the process of using strong acid or mordant to cut into the unprotected parts of a metal surface to create a design in intaglio in the metal ( the original process — in modern manufacturing other chemicals may be used on other types of material ).

The plate is then dipped in a bath of acid, technically called the mordant ( French for " biting ") or etchant, or has acid washed over it.

Some members produce a viscous or adhesive fluid which turns black and is used as a varnish or for tanning and even as a mordant for red dyes.

The tone of Sims's autobiography High Spirits is revealing ( though not sensationalist ), frank and sometimes mordant:

Randall Stuart " Randy " Newman ( born November 28, 1943 ) is an American singer-songwriter, arranger, composer, and pianist who is known for his mordant ( and often satirical ) pop songs and for film scores.

The dye is fixed to the cloth with help of a mordant, most commonly alum.

A mordant is a substance used to set dyes on fabrics or tissue sections by forming a coordination complex with the dye which then attaches to the fabric or tissue.

A mordant is often a polyvalent metal ion.

Iodine is often referred to as a mordant in Gram stains but is in fact a trapping agent.

:* Pre-mordanting ( onchrome ): The substrate is treated with the mordant and then dyed.

:* Meta-mordanting ( metachrome ): The mordant is added in the dye bath itself.

:* Post-mordanting ( afterchrome ): The dyed material is treated with a mordant.

The application of mordant, either pre -, meta-or post-mordant methods, is influenced by:

The dye lake is an insoluble molecule formed when the complex of dye and mordant are combined, which then attaches to the substrate.

In these applications, it is applied together with a mordant, usually an Al ( III ) salt.

A lake pigment is a pigment manufactured by precipitating a dye with an inert binder, or " mordant ", usually a metallic salt.

Others of Ní Dhomhnaill's generation were the mordant Michael Hartnett ( who wrote both in Irish and English ) and Michael Davitt ( d. 2005 ), a lyric poet whose work is both whimsical and melancholy.

The dye adhered to the cloth only where the mordant had been applied.

Mordant dyes require a mordant, which improves the fastness of the dye against water, light and perspiration.

The most important mordant dyes are the synthetic mordant dyes, or chrome dyes, used for wool ; these comprise some 30 % of dyes used for wool, and are especially useful for black and navy shades.

Vilmorin was best known as a writer of delicate but mordant tales, often set in aristocratic or artistic milieu.

Maslin felt that Mendes directed with " terrific visual flair ", saying his minimalist style balanced " the mordant and bright " and that he evoked the " delicate, eroticized power-playing vignettes " of his theater work.

The Queen Is Dead reached number two in the UK charts, and consisted of a mixture of mordant bleakness ( e. g. " Never Had No One Ever ", which seemed to play up to stereotypes of the band ), dry humour ( e. g. " Frankly, Mr. Shankly ", allegedly a message to Rough Trade boss Geoff Travis disguised as a letter of resignation from a worker to his superior ), and synthesis of both, such as in " There Is a Light That Never Goes Out " and " Cemetry Gates ".

Morrissey's lyrics, while superficially depressing, were often full of mordant humour ; John Peel remarked that The Smiths were one of the few bands capable of making him laugh out loud.

He joined the far left, and his energy and mordant eloquence speedily made him the leader of the Radical section.

They may also be used as a mordant in dyeing.

However, he was active in all of these areas: he persuaded his father to put up the capital, and his brothers to partner him in the creation of a factory ; he invented a mordant for cotton ; he gave technical advice to the dyeing industry ; and he publicised his invention of the dye.

In ecclesiastical matters he was a champion of the principles of the Tractarian revival ( a position not to his mind in the leastwise incompatible with mordant criticism of details and individuals ); he encouraged the wearing of the surplice, and was a pioneer in the restoration of diocesan synods, and became involved in controversy concerning religious sisterhoods in the Church of England.

The dye does not require a mordant and will readily stain the hand if picked without gloves.

It is prepared in situ by dissolving potassium dichromate in concentrated sulfuric acid, which is then used to wash the apparatus.

This method used the oxidizing agent potassium dichromate.

The impurities can be removed by passing the gas through aqueous sulfuric acid containing potassium dichromate.

Silver metal is attacked by strong oxidizers such as potassium permanganate () and potassium dichromate (), and in the presence of potassium bromide (); these compounds are used in photography to bleach silver images, converting them to silver halides that can either be fixed with thiosulfate or redeveloped to intensify the original image.

* orange ( potassium dichromate )

Early in the 1910s, several printers experimenting with photo-reactive chemicals used the well-known actinic light activated cross linking or hardening traits of potassium, sodium or ammonium Chromate and dichromate chemicals with glues and gelatin compounds.

The black reaction consisted in fixing silver chromate particles to the neurilemma ( the neuron membrane ) by reacting silver nitrate with potassium dichromate.

It is separated from coal tar by extracting with dilute sulfuric acid ; addition of potassium dichromate to this solution precipitates acridine bichromate.

An example is potassium dichromate, which does not pass the dangerous goods test of an oxidizing agent.

If colour negative film is processed in conventional black and white developer, and fixed and then bleached with a bath containing hydrochloric acid and potassium dichromate solution, the resultant film, once exposed to light, can be redeveloped in colour developer to produce an unusual pastel colour effect.

Other popular bleach solutions use potassium dichromate ( a hexavalent chromium ) or permanganate.

The overall contrast of the sensitizer solution can be increased with the addition of approximately 6 drops of 1 % ( w / v ) solution potassium dichromate for every 2 ml of sensitizer solution.

J & J White ’ s Chemical Works ( later ACC Chrome & Chemicals ) in Shawfield, which was in existence from 1820 to 1967, produced more than 70 % of the UK ’ s Chromate products including chromic acid, chromic oxide pigment, sodium and potassium chromate and dichromate.

The historical photography process of gum bichromate photography uses gum arabic mixed with ammonium or potassium dichromate and pigment to create a coloured photographic emulsion that becomes relatively insoluble in water upon exposure to ultraviolet light.

However, wool has thio groups (- SH ) from the cystine amino acid, which act as reducing agent and can reduce hexavalent chromium of potassium dichromate to trivalent form.

Its organic synthesis involves dissolving aniline, p-toluidine, and o-toluidine in sulfuric acid and water in a roughly 1: 1: 2 ratio, then adding potassium dichromate.

In one attempt, Perkin oxidized aniline using potassium dichromate, whose toluidine impurities reacted with the aniline and yielded a black solid — suggesting a " failed " organic synthesis.

The negative image is removed by bleaching with a solution of potassium permanganate or potassium dichromate in dilute sulfuric acid, which is removed by washing and a clearing bath containing sodium metabisulfite or potassium metabisulfite.

The classic Golgi stain uses potassium dichromate and silver nitrate to fill selectively with a silver chromate precipitate a few neural cells ( neurons or glia, but in principle any cells can react similarly ).