The name is absent

Figure 6.11: (a) Interaction force between the two grafted monolayers in the presence
of free polymer as a function of the separation between them for N₃ ■= 101, Ny = 100,
p₃σ₃ = 0.1, and Pfcr'j = 0.25. σ_g — σf = σ. (b) Interaction force between the two grafted
monolayers in the presence of free polymer as a function of the separation between them for
different bulk free polymer densities: Pf= 0.25 (dot-dashed curve), Pfσ'j = 0.4 (dashed
curve), Pfrf — 0.6 (dotted curve), and Pf^j = 0.75 (solid curve). Other parameters are
fixed at N₃ = 101, Ny = 100, p_gσ_g = 0.1, and σ_g = σy = σ.

the increase in the free polymer chain length. Furthermore, the attractive minimum
occurs only when the free polymer exceeds a certain minimum chain length.

Figure 6.13a shows that for a fixed grafting density and bulk free polymer density,
it is the ratio of the chain lengths of the free and grafted polymers, a = Nf∕N_g, that
determines whether the force is purely repulsive or has a attractive minimum. In this
figure, the grafting densities are scaled by ∖∕y∕^N_g. The figure shows that locus of the
critical values of a (i.e. the boundary between the purely repulsive and attractive
domains) calculated using modified iSAFT agrees with the scaling relation obtained
from previous theoretical studies using SST [209] and numerical SCFT [206, 208] :

170

<<   179   180   181   182   183   184   185   >>

More intriguing information