Effects of salinity on microemulsion based monoglyceride oily soil detergency using an extended surfactant

Abstract

The objective of this research was to apply a microemulsion-based formation with low salinity for oily soil detergency for monoglyceride removal from fabrics. To form middle phase microemulsions (Winsor Type III), three different surfactants were used: an extended surfactant (C₁₂¸₁₃-4PO-SO₄Na), an ionic surfactant; 1-dodecanol (CH₃(CH₂)₁₁OH), a lipophilic linker; and sodium mono- and dimethyl naphthalene sulfonate (SMDNS), a hydrophilic linker. Methyl palmitate was selected as a monoglyceride oily soil model. Two types of standard unsoiled fabrics were studied: pure polyester and polyester/cotton blend (65:35). For the detergency experiments, soiled fabrics were cleaned by using a Terg-O-Tometer at different total surfactant concentrations, salinities and washing temperatures (20 to 50ºC) to cover both below and above the melting point of the studied oil (30ºC). The results showed that the mixed surfactants of 55 part of C₁₂¸₁₃-4PO-SO₄Na, 41 part of 1-dodecanol, and 4 part of SMDNS provided a maximum detergency of 70 % oil removal at a 0.3 %w/v total surfactant concentration with an optimum salinity of 3 %ow/v at any washing temperature above the melting point. In addition, the re-deposition of removed oil decreased on all three types of fabrics as the washing temperature increased. The detergency efficiency on polyester/cotton blend fabric was the highest than that on other fabrics at any given washing temperature.