THE SUSPENDING POWER OF DETERGENT SOLUTIONS: I. PURE SOAPS

Abstract

The ability of soaps to prevent the deposition of carbon black and other materials on fabric during the detergent process has been investigated. In general the suspending power of the soap solutions studied increased rapidly with increasing soap concentration, and reached a maximum at a relatively low concentration. At higher concentrations the suspending power either remained constant or decreased slightly. With carbonaceous soils the indicated suspending power for a given soap increased, in general, with increasing particle size and decreasing "structure" of the carbon. With various soiling materials differences were encountered, not only in the magnitude of the indicated suspending power, but also in the form of the curve obtained on plotting suspending power vs. soap concentration. As measured by one type of carbon black (Standard Micronex) only minor differences were found between suspending powers of sodium myristate, palmitate, and stearate, all of which were higher than that of the laurate. Increasing temperatures caused a decrease in the suspending power of the lower chain length soaps (C12, C14) and an increase in the suspending power of the longer chain soaps (C16, C18). The suspending power of sodium oleate was essentially unchanged by temperature variations over the range 25–80 °C.