PROTEIN FILMS AT OIL-WATER INTERFACES: INTERFACIAL TENSION MEASUREMENTS BY THE STATIC DROP METHOD

ABSTRACT

A recently reported method of determining interfacial tension by static drop profile measurement has been used to examine the effect of protein on oil-water interfacial tension. The proteins -lactoglobulin (β LG) and bovine serum albumin (BSA) were adsorbed at the oil-water interface when the oil was corn oil, paraffin oil, tricaproin, and tricaprylin. Both proteins substantially lowered interfacial tension within the first minute by approximately the same amount for each oil. A much smaller lowering of surface tension then occurred over a twenty minute time period. At times from one to twenty-four hours, no further significant changes occurred. Addition of sodium dodecyl sulfate (SDS) after the twenty minute time period caused an additional and rapid lowering of interfacial tension, producing a final value near that for SOS alone at the interface.

Notes

Present Address: S. C. Johnson and Son, Inc., Racine, WI