Search results
Results from the WOW.Com Content Network
Another ancient document about the chemical coloring of metals is the Leyden papyrus X (3rd century CE). Zosimos of Panopolis, a Greek-Egyptian alchemist who lived in the late 3rd and early 4th centuries,is also extremely important, since to him attributed texts are considered to be the oldest written recipes for chemical coloring of metals. [7]
Ceramic colorants are added to a glaze or a clay to create color. Carbonates and oxides of certain metals, characterize most colorants including the commonly used cobalt carbonate, cobalt oxide, chrome oxide, red iron oxide, and copper carbonate. These colorants can create a multitude of colors depending on other materials they interact with ...
Electrochemical coloring of metals is a process in which the surface color of metal is changed by electrochemical techniques, i.e. cathodic or anodic polarization. The first method of electrochemical coloring of metals are certainly Nobili's colored rings, discovered by Leopoldo Nobili , an Italian physicist in 1826.
It is prepared by dissolving copper(II) hydroxide in an aqueous solution of ammonia. It forms an azure solution. Evaporation of these solutions leaves light blue residue of copper hydroxide, reflecting the lability of the copper-ammonia bonding. If conducted under a stream of ammonia, then deep blue needle-like crystals of the tetrammine form.
Mordant red 19 is a typical mordant dye. Like many mordant dyes, it features the azo group (RN=NR) and various sites for chelating to metal cations. A French Indienne, a printed or painted textile in the manner of Indian productions, which used mordants to fix the dyes
The intensity of the color depends on the copper : arsenic ratio, which in turn was affected by the ratio of the starting materials, as well as the temperature. It has been found that Scheele's green was composed of a variety of different compounds, including copper metaarsenite (CuO·As 2 O 3), copper arsenite salt (CuHAsO 3 and Cu(AsO 3) 2 ·3H
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
The Statue of Liberty, showing advanced patination; verdigris is responsible for the statue's iconic green colour.. Verdigris (/ ˈ v ɜːr d ɪ ɡ r iː (s)/) [1] is a common name for any of a variety of somewhat toxic [2] [3] [4] copper salts of acetic acid, which range in colour from green to a bluish-green depending on their chemical composition.