Structure of linear and star polyelectrolyte solutions as function of concentration
Alexandros Chremos, Jack F. Douglas
We investigate polyelectrolyte stars having a moderate number of arms by molecular dynamics simulations of a coarse-grained model, where both the counter-ions and solvent are treated explicitly, over a range of polyelectrolyte concentrations. This class of polymeric materials is found to exhibit rather distinct static and dynamic properties from linear and highly branched star polyelectrolytes investigated extensively in past studies. The moderately branched polymers are particle-like in many of their properties, while at the same time they exhibit large fluctuations in size and shape as in the case of linear chain polymers. Correspondingly, these fluctuations suppress crystallization at high polymer concentrations, leading apparently to an amorphous rather than a crystalline solid state. We quantify the onset of this transition by measuring the size and shape fluctuations of our model star polyelectrolyte and the static and dynamic structure factor of these solutions over a wide range of polyelectrolyte solutions. Our findings for star polyelectrolytes are similar to those of polymer- grafted nanoparticles having a moderate grafting density, which is natural given the soft and highly deformable shape of these particles.
and Douglas, J.
Structure of linear and star polyelectrolyte solutions as function of concentration, Journal of Chemical Physics, [online], https://doi.org/10.1063/1.4995534
(Accessed February 23, 2024)