EFFECT OF GRAVITY ON FOAM DECAY

FOAMS ARE USED IN MANY INDUSTRIES, YET THE MECHANISMS THAT CONTROL FOAM STABILITY ARE NOT WELL UNDERSTOOD. THE DECAY OF FOAM IS CONTROLLED LARGELY BY OSTWALD RIPENING OF LARGE FOAM CELLS AT THE EXPENSE OF SMALL FOAM CELLS. THE DECAY MECHANISM IS COMPLICATED BY GRAVITATIONAL EFFECTS. THE USE OF A NOVEL METHOD TO MEASURE FOAM STABILITY IS PROPOSED. BY MEASURING HEAD SPACE PRESSURE OVER A FOAM IN ACLOSED, THERMOSTATED CHAMBER, THE AREA DECAY OF THE FOAM CANBE COMPUTED. THE MEASUREMENT OF FOAM DECAY IN LOW GRAVITY IS THE ULTIMATE OBJECTIVE OF THE PROPOSED WORK. THE MEASUREMENT OF FOAM DECAY IN LOW GRAVITY WILL RESULT IN NOVEL INFORMATION THAT WILL AID THEORETICAL UNDERSTANDING OF FOAM DECAY AND OSTWALD RIPENING MECHANISMS. THE PHASE I OBJECTIVES ARE TO SELECT A FOAM SYSTEM FOR STUDY, AND TO DESIGN THE FOAM MEASUREMENT INSTRUMENT FOR A SPACE EXPERIMENT. THE PHASE I EFFORT WILL INVOLVE EXTENSIVETESTS OF THE REPRODUCIBILITY OF NUMEROUS FOAMS ON A PROTOTYPE INSTRUMENT. THIS INFORMATION WILL BE USED TO DESIGN A SPACE FLIGHT INSTRUMENT.