where -qs is in centipoises and the temperature Tk in Kelvins. The parameters thus determined are: (A-9.3±0.9, B=-0.049±0.006, and C=(6.8±0.9)10"5 for MCH), and are: (A=13±0.8, B=-0.068±0.005, and C=(9.2±0.8)10-5 for BrBz). The viscosity of SC CO2 was calculated using an empirical relation given by Sovova and Prochaska [22] (200 < T/K < 1500,0 < P/MPa< 100):

■H s = [(18.56+0.0147^ )(p-1 -7.41~10-4+3.3x10-7r^)]_1

where -qs is the viscosity of SC CO2 in [Pa s] and p is the density of SC CO2 in kg m3. The viscosity of PS-MCH and PDMS-BrBz solutions was fit to a function obtained from mode coupling theory [23]:

The product zv is predicted to be 0.034 and B is a constant of the order of unity. The"background" viscosity -q b of PS-MCH solutions measured far from the critical demixing temperatures is well described with the values of the parameters -qo = (2.2 ± 0.3) 10-3cP,andA=2700±400overtherange(5700 < Mw< 1 15000).

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