Coarse-Grained Modeling and Simulations of Thermoresponsive …
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4.4 Key Results
In Fig. 10, we show results for wetting behavior in PNCs with a single PGP made
of flexible graft and matrix chains with N G = 20, N M = 20 and = 0.65 chains/d
2 .
We compare PNCs with unfavorable graft-matrix interactions (or χ GM > 0) to PNCs
with purely entropic driving forces, i.e., no net attractive interactions between graft
and matrix chains in the model (χ GM = 0). At = 0.65 chains/d
2 , which is a
high grafting density, at the purely entropic limit, when matrix chain lengths are
equal to graft chain lengths one expects thermodynamic forces to favor matrixgraft interpenetration (wetting or mixing). In Fig. 10a, as χ GM increases from 0 to
+ 0.3, in the absence of A-D attraction (or h-bonds) the monomer concentration
profiles and brush heights show decreased concentration of matrix monomers within
the grafted layer. This suggests that the wetting of grafted layer by matrix chains
reduces as the graft-matrix interactions become enthalpically unfavorable compared
Fig. 10 Monomer concentration profiles (a, d) for graft and matrix monomers and probability
distribution of end-end distance, P(R ee ) versus R ee for graft chains (b, e) for PNCs with χ GM > 0
with repulsive A-D interaction (a, b) and attractive A-D interaction (d, e). For all plots, the legend
is as follows: χ GM = 0.1 with repulsive/attractive A-D interaction (dark cyan diamonds and dashed
line), χ GM = 0.3 with repulsive/attractive A-D interaction (red squares and solid line) and the purely
entropic case of χ GM = 0 and repulsive A-D interaction (black circles). Simulation snapshots of the
PNC show the grafted layer (matrix chains hidden) for c) χ GM = 0.1 with repulsive A-D interaction
and f) χ GM = 0.1 with attractive A-D interaction. All results are for D P = 5d, N G = 20, N M =
20 and = 0.65 chains/d 2 . Error bars where not visible are smaller than marker size. Parts of this
figure are adapted with permission from Ref. [154]. Copyright (2019) American Chemical Society
65
4.4 Key Results
In Fig. 10, we show results for wetting behavior in PNCs with a single PGP made
of flexible graft and matrix chains with N G = 20, N M = 20 and = 0.65 chains/d
2 .
We compare PNCs with unfavorable graft-matrix interactions (or χ GM > 0) to PNCs
with purely entropic driving forces, i.e., no net attractive interactions between graft
and matrix chains in the model (χ GM = 0). At = 0.65 chains/d
2 , which is a
high grafting density, at the purely entropic limit, when matrix chain lengths are
equal to graft chain lengths one expects thermodynamic forces to favor matrixgraft interpenetration (wetting or mixing). In Fig. 10a, as χ GM increases from 0 to
+ 0.3, in the absence of A-D attraction (or h-bonds) the monomer concentration
profiles and brush heights show decreased concentration of matrix monomers within
the grafted layer. This suggests that the wetting of grafted layer by matrix chains
reduces as the graft-matrix interactions become enthalpically unfavorable compared
Fig. 10 Monomer concentration profiles (a, d) for graft and matrix monomers and probability
distribution of end-end distance, P(R ee ) versus R ee for graft chains (b, e) for PNCs with χ GM > 0
with repulsive A-D interaction (a, b) and attractive A-D interaction (d, e). For all plots, the legend
is as follows: χ GM = 0.1 with repulsive/attractive A-D interaction (dark cyan diamonds and dashed
line), χ GM = 0.3 with repulsive/attractive A-D interaction (red squares and solid line) and the purely
entropic case of χ GM = 0 and repulsive A-D interaction (black circles). Simulation snapshots of the
PNC show the grafted layer (matrix chains hidden) for c) χ GM = 0.1 with repulsive A-D interaction
and f) χ GM = 0.1 with attractive A-D interaction. All results are for D P = 5d, N G = 20, N M =
20 and = 0.65 chains/d 2 . Error bars where not visible are smaller than marker size. Parts of this
figure are adapted with permission from Ref. [154]. Copyright (2019) American Chemical Society