Chapter 6 - Dynamics of single chains Flashcards Preview

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Flashcards in Chapter 6 - Dynamics of single chains Deck (7):
1

How is the Einstein relation defined?

D = kT/ç,

ç = friction coefficient.

2

How is the Stokes-Einstein relation defined?

D = kT/(6π*eta*R)

3

What is Stokes law?

Stokes law says that the friction coefficient of a sphere moving in a Newtonian liquid is

ç = 6π*eta*R

4

What is the Rouse model?

In the Rouse model, each polymer has N beads connected by springs of root-mean-square size b, each bead having a friction coefficient ç. The total friction coefficient is

ç_R = Nç,

and the diffusion coefficient is

D_r = kT/Nç.

5

What is the Rouse time?

The time it takes for a polymer to travel over a distance of the order of its size R.

tau_R = ç/kT * NR^2.

6

What modes are active for time scales shorter than the Rouse time in the Rouse model?

Viscoelastic modes.

7

What motion is seen on time scales longer than the Rouse time in the Rouse model?

Only diffusive motion.