The name is absent

stoichiometric mixture of ^ζm√ segments labeled from 1 till ɪn,, such that segments
‘1’ and ^ζm∕ have only one associating site, A or B, while the other segments have
two associating sites, A and B. This is depicted in fig. 2.2. Similarly, chains of other
types are formed. Using eqn. 1.6 in the bulk homogeneous limit, the free energy of
association between the segments of the chains is given by

Aassoc        ^mi           /          Va ι ∖

—— = W ‰ V I InXS--- + - ,        (2.8)

NkT             ^г ∖ a _{2     2} I >                ∖   >

г α=l A∈Γ<^α)                      '

where the first sum is over all the chain species, second over all the segments of a
chain ‘i’, and the third over all the associating∕bonding sites on segment ‘a’ of chain
‘i’. denotes the fraction of segments a that are not bonded at their associating site
A. The expressions for Хд are given by eqn. 1.7 in the bulk homogeneous limit. To
form chain molecules, the segments are bonded at contact. Furthermore, for chains
of type ^ζi^,, mid-segments a only bond to segments a — 1 and a ÷ 1 of the same type,
and end-segments 1 and 2 only bond to segments 2 and (m - 1), respectively. Hence
for chain ^li^,,

⁼ l + ₀A^fo+1>Δⁱⁱ'

where ∆ⁿ = X[exp(-e_assoc∕kT) — l]g₂⅞^f(⅛), Pi is the density of chains of type ^li^,, and

1

1 + p_iX^~^v,Δⁱⁱ

Chains are formed by increasing the strength of association such that e_assoc →

40

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