Freely Jointed Chain

2.1 Freely Jointed Chain

All bond lengths are the same
There is no correlation between the directions of bond angles, no treatment of torsional angles. ⟨cosθ_ij⟩ = 0 for i≠j.

2 2 ⟨R ⟩ = nl

(4)

2.1.1 Equivalent Freely Jointed Chain

We may represent an ideal polymer chain which for which we account for local interactions via C_∞ etc. by an equivalent freely jointed chain. The equivalent chain has the same fully extended length of the actual chain, R_max, and the same mean square end-end distance. It is composed of N subunits of length b such that Nb = R_max and < R² >= Nb² = C_∞nl², so that

-R2max- N = C ∞nl2 C ∞nl2 b = -R---- (5) max

Figure 2:

Equivalent freely jointed chain

[next] [prev] [prev-tail] [front] [up]