Miscibility and Nanoparticle Diffusion in Ionic Nanocomposites

Abstract

We investigate the effect of various spherical nanoparticles in a polymer matrix on dispersion, chain dimensions and entanglements for ionic nanocomposites at dilute and high nanoparticle loading by means of molecular dynamics simulations. The nanoparticle dispersion can be achieved in oligomer matrices due to the presence of electrostatic interactions. We show that the overall configuration of ionic oligomer chains, as characterized by their radii of gyration, can be perturbed at dilute nanoparticle loading by the presence of charged nanoparticles. In addition, the nanoparticle’s diffusivity is reduced due to the electrostatic interactions, in comparison to conventional nanocomposites where the electrostatic interaction is absent. The charged nanoparticles are found to move by a hopping mechanism.

Polymer Conformations, Entanglements and Dynamics in Ionic Nanocomposites: A Molecular Dynamics Study

“…This means that NPs are clustered (not dispersed) ( Figure 2d) in the nanocomposite. The extent of clustering depends on the matrix molecular weight as was also observed by a previous study [74]. To be specific, clustering is observed for NP volume fractions φ > 11.6% for matrices composed of end-charged N = 100, 200 polymers.…”

“…Next, we focus on the radial distribution functions (RDFs) of the NP center-monomer and NP center-charged monomer for the two different types of charged polymers with N = 200, at an NP volume fraction of φ = 11.6%, where NPs in both systems are dispersed. We can clearly observe from Figure 3 that the NP center-charged monomer RDF presents a much higher value of the first peak (inset of Figure 3b) than that in the NP center-monomer RDF (inset of Figure 3a) [74]. This shows that there are more monomer contacts between the charged monomers and oppositely charged surface beads, than neutral monomers and neutral surface beads, due to the electrostatic attraction.…”

Ion Transport in Organic Electrolyte Solutions for Lithium-ion Batteries and Beyond

“…In addition, the diffusion coefficients of 14 pure organic solvents, such as EC, tetrahydrofuran (THF), γ-Butyrolactone (GBL) [116] appeared to exhibit a good correlation with viscosity, according to the Stokes-Einstein relation [84,129]:…”

Insights from modeling into structure, entanglements, and dynamics in attractive polymer nanocomposites

“…2 For nanocomposites containing carbon nanotubes, w p-NP had been calculated from the square of pure-component solubility parameters for many different polymers. 3 An effective attraction 4 can originate either from hydrogen bonds, [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] p-p stacking [21][22][23][24] and ionic [25][26][27][28][29][30][31][32] or other types of interaction. 23,[33][34][35][36] The addition of NPs alters polymer rheology, [37][38][39][40][41] which affects transport 42,43 and flow.…”