CHEM 4214 Lecture Notes - Lecture 24: Intrinsic Viscosity, Viscometer, Dispersity
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9:28 am: meausre number avg mw from osmotic pressure, light scatterring for weight avg molecular weight. Quiz: in guinier limit, shape of molecule doesn"t matter need mw to find rg: viscosity (rheology) Viscosity the bigger the plate, the more force we"ll need to move the platethis is trivial so we want to normalize the force velocity gradient (shear rate) -> shear stress shear stress is proportional to shear rate eta = viscosity [=] pa s ex: water has viscosity of 1 mpa s at room temperature. Chem4212 polymers page 2 formula says this only depends on volume fraction but not on size of particle gives us dilute solution. Intrinsic viscosity c = g/ml concentration compare this to einstein definition thisis not equal to viscosity, which is in units of pa s. N = degree of polymerization most case, use the 2nd one (in reality, should use something in between each one) for hard sphere, fluid flows around sphere.
