Re: "orvus"

["Mary W. Ballard" <BallardM@xxxxxxxxxxxx>]

Just a few quick notes: 1) Orvus is the trade name (like Igepal or Tergitol) for a group of surfactants. The Orvus WA Paste used in North America is sodium dodecyl sulfate. 2) This surfactant is one of the most well researched surfactants in the world and consequently, its advantages and disadvantages can largely be found in the textile science literature. 3) It also was often used in textile science work on related matters. One such article is W.C. Preston's work on Critical Micelle Concentration  in J. Phys. Colloid Chemistry, vol 52 #84 (1948).* His Figure 3-2 shows the changes in physical properties of an aqueous solution of SDS in the neighborhood of the critical micelle concentration: there are changes in interfacial tension, equivalent conductivity, osmotic pressure, surface tension, conductivity, density, and detergency. Each measurement will give you a different cmc, averaged together (usually by the manufacturer), you will arrive at the cmc, but one measurement or an!
other may be more useful. 4) This is distinct and different from the efficacy of the soil removal of the surfactant from a particular fiber type. Mary
*if you cannot find this article in your local university library, and you email me privately (at ballardm@xxxxxxxxxxxxx ) I can mail you a copy.