A novel surface shear viscometer.
A novel rotary viscometer--developed for the determination of rheologic properties of liquid/air interface layers--is presented. The instrument can be used to measure the shear viscosity and the shear elasticity of liquid surfaces. It contains a rotor floating on the liquid surface which is rotated by means of an electromagnetic torque. A torsion filament is used to calibrate the applied torque. The viscosity data are obtained on the basis of the Navier-Stokes equation solved for the rotation of a cylinder touching the surface of water and submerged into the water. The time behavior of the surface viscosity of films gradually formed from solutions of some proteins as well as their activation energy is presented.
Bánó
Mikulás
M
Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04053 Kosice, Slovakia. bano@saske.sk
Pudlák
Michal
M
Tomori
Zoltán
Z
Demjén
Erna
E
Hrmo
Igor
I
Bothová
Hedviga
H