364 JOURN•,L OF THE SOCIETY OF COSMETIC CHEMISTS Officers and Committee Chairmen of the Midwest Chapter of the Society of Cosmetic Chemists Leit to right: (seated) Chairman of Policy and Bylaws William Ackley, Chairman of House Committee Linda Allen, Publicity Chairman Stanley Allured, Cbairnian Joseph J. Jerome, Chairman-Elect Betty Lou Day, Education Chairman Julius Wagman (standing) Program Chairman Paul Silverman, Past Chairman Hy Henkin, Hospitality Chairman Jean Snyder, Membership Chairman Robert Berke, Secretary Martha Depeder, Treasurer Robert Arm- strong, Ladies Night Chairman Richard Scbranz. Not in attendance were Interprofessional Relations Chairman Aaron Miller, Finance Chairman Chester Moculeski, Newsletter Chair- man Eileen Brady, and Awards Chairman Jesse Starkman

J. Soc. Cosmet. Chem., 21, 365-375 (May 27, 1970) Surfactant Location Required HLB* and TONG JOE LIN, Ph.D.* Presented September 9, 1969, Seminar, St. Louis, Mo. Synopsis--Previous studies indicate that the location of the surfactant at the time of emulsifi- cation plays a very important role in determining the physical properties of the EMULSIONS formed. In this investigation, the HLB required to form an O/W emulsion was studied as a function of the initial SURFACTANT LOCATION in the OIL AND AQUEOUS PHASES prior to emulsification. Placing the surfactant blend in the aqueous phase prior to emulsification generally re- sulted in an apparently lower value of required HLB than the same system prepared by ini~ tially dispersing the surfactant blend in the oil phase. The initial surfactant location also showed a marked effect on emulsion stability. In the systems studied, using the emulsifica- tion technique described, placing the surfactants in the oil phase produced more stable emul- sions than the same systems prepared by initially placing the surfactants in the aqueous phase. INTRODUCTION Since Griffin first introduced the HLB (hydrophile-lipophile bal- ance) concept in 1949, a considerable amount of work has been done by many investigators to develop further the methods of measurement, to extend its applications, and to find the theoretical significance of the con- cept (1-4). HLB values of surfactants were originally obtained by a laborious de- termination of emulsion stability. Although such a method is still used, a number of other techniques have been proposed in recent years. * Research work was conducted while the author was with Max Factor 8c Co., Hollywood, CaliL *Shen Hsiang Tang Chemical Works, 19 Fu Shin Road, Section 4, Talchung, Taiwan. 365