Submitted Abstract
Fundamentally important to the processability and the material properties of polymernanocomposites is the underlying interaction between polymer and nanoparticles, theresulting structure and dynamics. A high degree of nanoparticle dispersion is necessary for an effective reinforcement in a polymer matrix. A recent experimental approach to distributing nanoparticles into a polymer matrix is to let the interaction between nanoparticles and polymer chains to be of ionic nature. Ionic nanoparticles can impart charged polymers with unique mechanical and functional properties such as self-healing and shape memory. Upon studying a single model nanocomposite via molecular simulation, we found that nanoparticle dispersion can indeed be achieved due to the insertion of electrostatic charge, that nanoparticle diffusion slows down due to this electrostatic charge, and that the ionic nanoparticles move according to a hopping mechanism. These recent findings have the potential to spur new studies in modelling ionic polymer nanocomposites containing ionic functionalized silica nanoparticles. We hereby propose to focus in a more detailed and conclusive fashion on four combined experimental/theoretical research objectives: (i) Investigate the role of ionic interactions and calculate viscoelastic properties (viscosity, storage modulus, loss modulus) with nanoparticle loading, for differently charged and sequenced polymers. (ii) Quantify the lifetime of dynamic crosslinks between nanoparticles and polymers, formed in ionic nanocomposites, during deformation processes. (iii) Calculate the dynamics and structure of polymers and their entanglements for differently charged and filled polymer ionic nanocomposite models, (iv) Resolve the role of nanosilica surface confinement on polymer entanglements and dynamics. The novelty of the proposed work stems from the combination of experiments, simulation and theoretical models to capture the interactions and polymer structural/dynamical, as well as rheological phenomena present in these ionic nanocomposites, who seem to offer qualitatively new properties worth being quantified and supplemented with an informed microscopic picture.