3 research outputs found
Tension Amplification in Tethered Layers of Bottle-Brush Polymers
Molecular
dynamics simulations of a coarse-grained bead–spring
model have been used to study the effects of molecular crowding on
the accumulation of tension in the backbone of bottle-brush polymers
tethered to a flat substrate. The number of bottle-brushes per unit
surface area, Σ, as well as the lengths of the bottle-brush
backbones <i>N</i><sub>bb</sub> (50 ≤ <i>N</i><sub>bb</sub> ≤ 200) and side chains <i>N</i><sub>sc</sub> (50 ≤ <i>N</i><sub>sc</sub> ≤ 200)
were varied to determine how the dimensions and degree of crowding
of bottle-brushes give rise to bond tension amplification along the
backbone, especially near the substrate. From these simulations, we
have identified three separate regimes of tension. For low Σ,
the tension is due solely to intramolecular interactions and is dominated
by the side chain repulsion that governs the lateral brush dimensions.
With increasing Σ, the interactions between bottle-brush polymers
induce compression of the side chains, transmitting increasing tension
to the backbone. For large Σ, intermolecular side chain repulsion
increases, forcing side chain extension and reorientation in the direction
normal to the surface and transmitting considerable tension to the
backbone