Polymer and spherical nanoparticle diffusion in nanocomposites

Abstract

Nanoparticle and polymer dynamics in nanocomposites containing spherical nanoparticles were investigated by means of molecular dynamics simulations. We show that the polymer diffusivity decreases with nanoparticle loading due to an increase of the interfacial area created by nanoparticles, in the polymer matrix. We show that small sized nanoparticles can diffuse much faster than that predicted from the Stokes-Einstein relation in the dilute regime. We show that the nanoparticle diffusivity decreases at higher nanoparticle loading due to nanoparticle -polymer interface. Increase of the nanoparticle radius slows the nanoparticle diffusion.

Structure and Dynamics of a Polymer–Nanoparticle Composite: Effect of Nanoparticle Size and Volume Fraction

“…Liu et al [27] have observed a reduction of the NP diffusion coefficient with increasing φ N , and attributed the phenomenon to polymer-mediated interactions, i.e., to the formation of chain bridges between neighboring NPs that would hinder NP motion; it is not clear, however, what the typical lifetime of such bridges should be, and thus whether this explanation is correct. Karatrantos et al [32] have observed a similar reduction in NP mobility and argued that it is due "to both nanoparticle-polymer surface area and nanoparticle volume fraction" [32], implying that pure geometry and polymer-NP attraction both play a role. The importance of polymer-NP interaction in NP dynamics is beyond dispute: Patti [29] showed that the diffusion coefficient of NPs in an unentangled melt decreases monotonically when the strength of the polymer-NP interaction is increased, with the decrease being stronger for smaller NPs.…”

Effect of Crosslinker Length and Architecture on the Thermomechanical Properties of CNT‐Loaded Elastomeric Polymer Matrix Composites

“…However, further CNT addition continues to increase the interfacial area between the polymer and CNT, thus enhancing storage modulus. Recent simulation efforts from Clarke and co‐workers showed a similar effect; namely, that increasing the polymer‐nanoparticle interfacial area decreases the polymer diffusivity . This finding is important for designing composites, recognizing that the storage modulus can be tailored independent of the T g to some extent.…”

The effect of different organic solvents on sodium ion storage in carbon nanopores

“…However, such approach is very computationally expensive and would increase an order of magnitude the computational cost [46]. Using such a molecular simulation methodology, we can easily tune to carbons of different physical and chemical properties or different organic solvents to extrapolate ion storage, diffusion [47] and, capacity under charge/ discharge cycles [48] and under operating conditions.…”