Articles:
Microemulsion Formation and Detergency with Oily Soils: I. Phase Behavior and Interfacial Tension
The ultimate objective of the project was to investigate the relationship between mlcroemulsion phase behavior and detergency for oily soils. In this study. surfactant phase behavior was evaluated for hexadecane and motor oil as model oiiy soils. Producing microamulsions with these oils is particularly chalenging because ot their large hydrophobic character. To produce the desired phase behavior we included three surfactants with a wide range of hydrophilic/lipophilic character: alkyl diphenyl oxide disullonate (highly hydrophilic). dioctyi sodum sulfosuccinate (intermediate character), and sorbitan monooleata (hydrophobic). This mixed surfactant was able to bridge the hydrophilidlipophilic gap between the water and the oil phases, producing mlcroernulsions with substantial solubilisation and ultralow interfacial tension. The effects of surfactant composition, temperature, and salinity on system performance were investigated. The transition of microemulsion phases could be observed for both systems with hexadecane and motor oil. ln addition, the use of surfactant mixtures containing both anionic and nonionic surfactants leads to systems that are robust with respect to temperature compared to single-surfactant systems. Under conditions corresponding to “supereolubilization,“ the solubilization parameters and oil/microemulslon interfacial tensions are not substantially worse than at optimal condition for a middle-phase system, so a middle-phase rnicroernulsion is not necessary to attain quite low interfacial tensions. A potential drawbadt ol the formulations developed here is the fairly high salinity (e.g., 5 wt% NaCl) needed to attain optimal middle-phase systems. The correlation between interfacial tension and solubillzetion follow the trend predicted by the Chun-Huh equation. Paper no. S1361 in JSD 6. 191-213 (July 2003).
Microemulsion Formation and Detergency with Oily Soils: II. Detergency Formulation and Performance
In part I of this series (J. Surfact. Deterg. 6, 191-203,2003), the mixed surfactant system of sodium dioctyl sulfosuccinate (AOT) on alkyl diphenyl oxide disulfonate (ADPODS) and sorbitan monooleate (SpanSO) was shown to form Winsor type I and type III microemulsions with hexadecane and motor oil. In addition, high solubilization and low inter facial tension were obtained between the oils and surfactant solutions, both in the super solubilization region (Winsor type I system close to type III system) and at optimal conditions in a type III system. In the present study, this mixed surfactant system was applied to remove oily soil from fabric (a polyester / cotton blend), and detergency results were correlated to phase behavior. Dynamic interfacial tensions were also measured between the oils and washing solutions. In the supersolubilization and the middle-phase regions (type III), much better detergency performance was found for both hexadecane and motoroil removal than that with a commercial liquid detergent product. In addition, the detergency performance of our system at low temperature (25°C) was close to that obtained at high temperature (55"C), consistent with the temperature robustness of the microemulsion phase behavior of this system.
Recommended Reading
Detergency of Specialty Surfactants, , F. E. Friedli, Marcel Dekker, New York, NY (2001)
Formulating Detergents and Personal Care Products: A Guide to Product Developmen, , L.H.T. Tai, AOCS Press, Champaign, Illinois (1999)
Powdered Detergents, , M.S. Showell, Ed., Marcel Dekker, New York (1998)
Enzymes in Detergency, , J.H. van Ee, O. Misset, and E.J. Baas, Eds., Marcel Dekker (1997)
Liquid Detergents, , K-Y. Lai, Ed., Marcel Dekker, New York (1997)
Detergents and Cleaners: A Handbook for Formulators, , K. R. Lange, Hanser, Munich, 1994
Surfactants in Consumer Products, Theory, Technology and Application, , J. Falbe, Ed., Springer-Verlag, Berlin, 1987, Chapters 5 and 11
Detergents and Textile Washing, , G. Jakobi and A. Lohr, Eds., VCH, Weinheim, Germany, 1987
Detergency, , W. G. Cutler and R. C. Davis, Eds., Marcel Dekker, New York, Parts I - III, 1973-1981
Kirk-Othmer Encyclopedia of Chemical Technology, 4th Edition, , Lynn, J. L. Wiley, New York, Vol. 7, p. 1012 (1993)
Advanced Cleaning Product Formulations: Household, Industrial, Automotive, , E. W. Flick, Noyes Publications, Park Ridge, NJ, 1989
Advanced Cleaning Product Formulations, Volume 2, , E. W. Flick, Noyes Publications, Park Ridge, NJ, 1994
Cationic Surfactants: Physical Chemistry, , D. N. Rubingh and P. M. Holland, Eds., Marcel Dekker, New York, 1990, Chapters 9 and 10
Soap Technology for the 1990’s, , L. Spitz (Ed.), American Oil Chemists’ Society, Champaign, Illinois, 1990
Kirk-Othmer Encyclopedia of Chemical Technology 4th Edition, , Farr, J. P., Smith, W. L., and Steichen, D. S. New York Vol. 4, 27 (1992)
The Role of Oil Detachment Mechanisms in Determining Optimum Detergency Conditions, , Thompson, L., J. Colloid Interface Sci., 163, 61 (1994). [NOTE: an excellent paper with a good literature survey on the topic.]
The Science of Hair Care, , Zviak, C., Ed., Marcel Dekker, New York (1986)
Handbook of Detergents, Part A: Properties, , G. Broze, Ed., Marcel Dekker, New York, 1999
Industrial Cleaning Technology, , J. Harrington, Ed., Kluwer Academic Publishers, London, UK (2001)