The term persulfate refers to ions or compounds with more oxygen than normal sulfates.
These do not have sulfur in a different oxidation state; rather, they contain peroxide units, where two oxygens take the place of one in a normal sulfate; the oxygen atoms are in oxidation state -1.
The main forms are peroxomonosulfates and peroxodisulfates.
Ammonium persulfate (NH4)2S2O8 has been prepared by H. Marshall by the method used for the preparation of Potassium persulfate. It is very soluble in cold water, a large fall of temperature accompanying solution. It is a very strong oxidizing agent and a radical initiator. It is used to etch copper on printed circuit boards as an alternative to ferric chloride solution It is also used along with tetramethylethylenediamine to catalyze the polymerization of acrylamide in making a polyacrylamide gel.
Potassium persulphate (K2S2O8) is a chemical compound. It is a food additive and it is used in organic chemistry as an oxidizing agent for instance in the Elbs persulfate oxidation.
Conditions/substances to avoid are: heat, flames, ignition sources, powdered metals, phosphorus, hydrides, organic matter, halogens, acids and alkalis.
It is used as a bleach, both standalone (particularly in hair cosmetics) and as a detergent component. It is a replacement for ammonium persulfate in etching mixtures for zinc and printed circuit boards, and is used for pickling of copper and some other metals. It is a source of free radicals, making it useful as a radical initiator for emulsion polymerization reactions and for accelerated curing of low formaldehyde adhesives. It is also used as a soil conditioner and in manufacture of dyestuffs, modification of starch, bleach activator, desizing agent for oxidative desizing, etc.
Conditions/substances to avoid mixing persulfates with are: moisture, heat, flame, ignition sources, shock, friction, reducing agents, organic material, sodium peroxide, water, aluminum and powdered metals.