Fig. 4.

Filament diameter $d_{min}/d_0$ as a function of time for the PEO solutions surrounded by air ($○,\square$) and the 0.65 cSt SO (×, ∗) measured at T = 20 ± 1 °C. The extensional relaxation times measured in air are λ = 1.01 ± 0.03 ms and 3.9 ± 0.3 ms for PEO100 and PEO500, respectively, while the extensional relaxation times measured in the silicone oil are λ = 1.27 ± 0.04 ms and 3.89 ± 0.01 ms for PEO100 and PEO500, respectively. For clarity, in the case of PEO100, we only plot one quarter of the points, while for the PEO500 we only plot one tenth of the points. The dashed lines indicate the fits to obtain the relaxation times. The diameter of the rods is d ₀ = 2 mm