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Polymers in Confined Geometry.pdf

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84 APPENDIX B. CALCULATION FOR THE CONFINED POLYMER<br />

the first <strong>in</strong>tegral is calculated here, the others are evaluated <strong>in</strong> the same way,<br />

s s ′<br />

s (τ−s ′ )/ld<br />

dτ<br />

dτ dx e −x <br />

s<strong>in</strong> x − π<br />

<br />

4<br />

s ′<br />

0<br />

dτ ′ K(τ − τ ′ ) = −ld<br />

s ′<br />

s<br />

= ld<br />

√2<br />

= l2 d √2<br />

= l2 d<br />

2<br />

dτ<br />

<br />

e<br />

τ/ld<br />

s ′<br />

(s−s ′ )/ld<br />

τ−s′<br />

− ld s<strong>in</strong><br />

0<br />

<br />

1<br />

√2 − e s−s′<br />

ld s<strong>in</strong><br />

s<br />

− l + e d s<strong>in</strong><br />

s<br />

ld<br />

τ − s′<br />

ld<br />

dy e −y s<strong>in</strong> y −<br />

τ<br />

− l − e d s<strong>in</strong> τ<br />

ld<br />

s ′ /ld<br />

s/ld<br />

′ s − s<br />

+<br />

ld<br />

π<br />

<br />

4<br />

′ s<br />

− π<br />

<br />

s′<br />

− l − e d s<strong>in</strong><br />

4<br />

ld<br />

<br />

dz e −z s<strong>in</strong> z<br />

<br />

− π<br />

<br />

. (B.9)<br />

4<br />

The trigonometric relations used can be found <strong>in</strong> [1]. Calculat<strong>in</strong>g the rema<strong>in</strong><strong>in</strong>g<br />

<strong>in</strong>tegrals and comb<strong>in</strong><strong>in</strong>g the results gives<br />

〈R(s) · R(s ′ <br />

)〉 = 1 − ld<br />

<br />

ss<br />

2 lp<br />

′ + l3 d<br />

2 √ <br />

e<br />

2 lp<br />

− |s−s′ <br />

|<br />

′ |s − s |<br />

ld s<strong>in</strong> +<br />

ld<br />

π<br />

<br />

4<br />

<br />

s<br />

− s<br />

l − e d s<strong>in</strong> +<br />

ld<br />

π<br />

<br />

s′ ′<br />

− s l − e d s<strong>in</strong> +<br />

4<br />

ld<br />

π<br />

<br />

+<br />

4<br />

1<br />

(B.10)<br />

√<br />

2<br />

valid for all s, s ′ .<br />

From this result the mean-square end-to-end distance is obta<strong>in</strong>ed <strong>in</strong> the l<strong>in</strong>es<br />

follow<strong>in</strong>g eq. (3.37).<br />

B.3 Parallel end-to-end distance correlation<br />

The mean-square end-to-end distance is calculated <strong>in</strong> detail, by <strong>in</strong>sert<strong>in</strong>g the<br />

derivatives of the average undulations eqs. (3.30) and (3.31) <strong>in</strong> eq. (3.40)<br />

˙R||(s) ˙ R||(s ′ ) = d2<br />

ds ds ′<br />

R||(s)R||(s ′ ) <br />

= 1 − ld<br />

+<br />

2 lp<br />

l2 d<br />

16 l2 p<br />

+ l2 d<br />

8 l2 e<br />

p<br />

−2 |s−s′ |<br />

ld s<strong>in</strong> 2<br />

′ |s − s |<br />

−<br />

ld<br />

π<br />

4<br />

<br />

=〈 ˙r ||(s) ˙r ||(s ′ )〉<br />

<br />

. (B.11)<br />

An <strong>in</strong>tegration for s ≥ s ′ yields the desired result for the projected length correlation<br />

<br />

R||(s)R||(s ′ ) s s ′<br />

= dτ dτ<br />

0 0<br />

′ R||(s) ˙ ˙ R||(s ′ ) <br />

<br />

= 1 − ld<br />

+<br />

2 lp<br />

l2 d<br />

16 l2 <br />

ss<br />

p<br />

′ + l2 d<br />

8 l2 s s ′<br />

dt dt<br />

p 0 0<br />

′ K(|τ − τ ′ |), (B.12)

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