二平板間の重力による流れを利用した高分子水溶液と界面活性剤水溶液の第2法線応力差の測定

抄録

The second normal stress is measured for aqueous solutions of Separan with polymer weight fraction from 1% to 3% and for 10^-2 mol/l aqueous cetyltrimethylammonium bromide (CTAB) solution containing 1.5×10^-2 mol/l of sodium salicylate (NaSal) as an added salt. The measuring device is a newly developed one composed of two parallel plates vertically set and opened to the atmosphere at the sides, and the solution is made to flow down through the slit between the two parallel plates by the gravity.The torque on one of the plates induced by the flow is measured and the second normal stress difference is estimated. The second normal stress difference obtained is negative for Separan solutions, and its absolute value is found to be of the same magnitude as the shear stress. For the CTAB: NaSal aqueous solution, the second normal stress difference is negative and the magnitude is larger than the values for Separan solutions.
Its absolute value is 1-10% of the first normal stress difference.