Dipolar and chain-linking effects on the rheology of grafted chains in a nanopore under shear at different grafting densities

Nonequilibrium molecular dynamics simulations were performed to probe structural and dynamical properties of tail-grafted, amphiphilic chains under shear at different grafting densities. Emphasis was put on the modification of the head groups in order to investigate to which extent this modification of the interfacial region could specifically control the mechanical properties. By considering two different grafting densities, the effect of dipolar forces across the nanopore with increasing load was addressed. In general, it was found that interfacial viscosities and friction forces increase in tail-grafted amphiphilic systems where repulsive head-group interactions are significant.