A COAXIAL CYLINDER RHEOMETER FOR GEL STRUCTURE CHARACTERIZATION

A SENSITIVE COAXIAL CYLINDER RHEOMETER WAS BUILT AND CALIBRATED WITH A NEWTONIAN FLUID. THE RHEOMETER IS OF THE COAXIAL CYLINDER TYPE IN WHICH A BOB ROTATES IN A STATIONARY CUP. THE AMOUNT AND/OR RATE OF ROTATION OF THE BOB IS MEASURED OVER A LIMITED RANGE BY THE MOTION OF A REFLECTED LIGHT BEAM. OPERATING CHARACTERISTICS OF THE INSTRUMENT WERE FURTHER INVESTIGATED USING A CERAMIC SLIP. IT WAS SHOWN THAT THE INSTRUMENT IS CAPABLE OF APPLYING SHEARING STRESSES LESS THAN THOSE REQUIRED TO CAUSE A GELLED SLIP TO FLOW. RESPONSE OF A GELLED SLIP TO THESE LOW STRESSES RESEMBLED VISCOELASTIC BEHAVIOR. /AUTHOR/