Correlation between Detergency of Different Oily and Solid Non‐Particulate Soils and Hydrophilic–Lipophilic Deviation

Abstract

This research examined the correlation between the detergency of soils with varying equivalent alkane carbon numbers (EACN) and hydrophilic–lipophilic deviation (HLD) values. The detergency of oily soils with EACN ranging from 5.2 to 16.6 was evaluated using C10‐4PO‐SO4Na as a primary surfactant system and a 1:1 binary mixture of C10‐4PO‐SO4Na and AOT as a confirmatory surfactant system (with 65/35 polyester/cotton at 25°C). These surfactant systems were characterized using HLD concepts which showed that C10‐4PO‐SO4Na was more hydrophilic (had a higher negative Cc value) than that of the mixed surfactant system. Detergency of the selected soils was evaluated at different salinities corresponding to HLD ranging from negative to positive values. The results showed that detergency of all soils increased with increasing salinity (starting with an HLD = −3.0 (Winsor Type I microemulsion)), reached the maximum at widely different optimum salinity (S*) but at an identical HLD value of zero (optimum Type III), and then decreased with further increasing salt levels corresponding to positive HLD values (Type II). The preferred HLD range from −3.0 to 0.0 showed detergency levels exceeding 80% removal with interfacial tension values (IFT) below 1 mN m−1 for all oily soils studied. Detergency of octadecane (EACN = 18, solid at 25°C) was further conducted and demonstrated that performing detergency at HLD = −3.0 to 0.0 likewise revealed superior soil removal (over 80%) versus systems with HLD values outside this range. Thus, this work highlighted the utility of using the HLD approach in designing surfactant formulations for detergency of soils with widely varying EACN.

Non‐linearchanges in phase inversion temperature for oil and water emulsions of nonionic surfactant mixtures

“…Historically, this term was used to describe SOW conditions that correspond to a minimum in interfacial tension in the context of Winsor III microemulsion formation, which are held to be optimal for enhanced oil recovery application (Salager et al, 1979). For many applications, optimal performance may not reside at an HLD = 0 state, but at some specific range of distance from it (Bourrel et al, 1980; Phaodee et al, 2020; Salager et al, 1982, 2020). An optimal condition can be identified for each variable in Equation (), while holding the others constant.…”

Formulation in Surfactant Systems: From-Winsor-to-HLDN

“…Phaodee et al [270] worked with solid non-particulate soils (solidified coconut oil) at 10C with only 45% removal at high salinity (8% NaCl). Then, a year later, detergency higher than 90% removal was found at these cold temperatures using an octanol cosurfactant at 90 mmol, which probably acted as lipophilic linker, with an IFT of 0.03 mN/m [91,269].…”

“…Another important use of the numerical value of the formulation quantification is cleaning and detergency. An HLDN negative value in the range from -5 to -15 (close to zero but not necessarily at the optimum) is also essential to displace some greasy dirt from cloth, as well as to change the solid particle wettability around 0 to attain good detergency [79,[265][266][267][268][269][270]. Although the detergency effectivity is related to the dirt's characteristic (like its exact EACN if it is an oil phase), and thus can change from place to place, this is a general tendency empirically used in the past 100 years.…”

Detergency mechanisms and cellulosic surfaces: A review

“…Figure 6 shows two widely used examples. The headgroup is usually sulfonate or sulfate, both of which become fully dissociated over the whole pH range at which laundering takes place (Scheibel 2004;Ponnusamy et al 2008;Budhathoki et al 2016;Phaodee et al 2020). Schott (1967)…”