Bichromal particles

Membrane and microfiuidic devices have also been adopted for the precision manufacture of solids from double-emulsion templates. To date, several different types of particles have been successfully produced by incorporating use of various membrane and microfiuidic devices in processes of polymerization, gel formation, crystallization, and molecular or particle self-assembly. Membrane emulsification is more suited to the fabrication of less sophisticated particulates, such as solid lipid micro-Znanoparticles, gel microbeads, coherent polymeric microspheres, and inorganic particles such as silica microparticles. Microfiuidic devices allow more sophisticated particle designs to be created, such as colloidosomes, polymerosomes, 3D colloidal assemblies, asymmetric vesicles, core-shell polymer particles, and bichromal particles. 

The new propellant was promising but the nitrocellulose smokeless powder invented soon afterwards superseded all mixtures containing potassium nitrate and similar salts, that give a number of solid particles when exploded. For a time in the United States various mixtures were still used instead of blackpowder—chiefly for sporting purposes. E.g. Gold Dust Powder (Starke [36]) consisted of 55% ammonium picrate, 25% potassium picrate and 20% ammonium bichromate. Soon, however, early in the nineteenth century, the use of these mixtures was discontinued. 

Morphin is often contaminated with narcotic, which may be entirely removed by ether, or the impure mass may be treated with very dilute acetic add which dissolves the former, leaving the latter untouched. To determine the purity—from nareotin—of any sample of morphin, it may be dissolved in hydrochloric acid, and treated with caustic potassa in excess, in which the morphia will entirely dissolve, while any narcotin present remains untouched. If a very small portion of morphia is placed in a watch-glass with, a little pure sulphuric aoid and au equal quantity of water, and if a particle of bichromate of potassa be added, a nickel green color appears, which changes, first to a copper green, and finally, to a dark dirty green. 

Or, put a minute particle into a watch-glass, drench it with five or six drops of pure salphurio acid and an equal quantity of water, and odd a fragment of bichromate of poises a. If qninin is present, the mixture will first assume a green shade resembling that of arsemate of oopper, then a beautiful yellow green, and finally a vor.. Tl,... 

Lead chromates and lead molybdates are produced by precipitation of soluble salts in aqueous media. Various lead sources include litharge, lead nitrate, basic lead actetate, and lead carbonate. The lead carbonate and basic lead acetate are used primarily to control particle size. Other ingredients include acids, alkalis, sodium bichromate, and sodium chromate. Additionally, molybdate orange manufacture involves the use of sodium molybdate and sodium sulfate as raw materials. 

Procedure. A drop of the test solution, or a particle of the solid sample, is mixed with a drop of a 5 % KI-KIO3 solution, stirred, and a drop of starch solution added. When bichromate is present a distinct blue appears, at most after 6 minutes. The reagent solution should be freshly prepared. 

Depressants are chemicals that make the particle surface hydrophilic and nonfloatable. Typical depressants include bichromate, cyanide, zinc sulphate, and lime. 

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