Fig. 1. (a) Half-life time t1/2 as a function of temperature of foams prepared from 0.5 g l–1 hydroxypropyl cellulose (HPC) aqueous solutions with 0 (squares) and with 0.7 M NaCl (circles). (b) Time td,75 until 75% of the liquid content in the foam has drained as a function of temperature. In (b) squares represent the results for 0.5 g l–1 HPC solutions without NaCl, while circles represent the HPC solutions with 0.7 M NaCl. Solid lines in (a) and (b) guide the eye.
