Structure and Dynamics of Interacting Nanoparticles in Semidilute Polymer Solutions

Abstract

We investigate the structure and dynamics of silica nanoparticles and polymer chains in semidilute solutions of high molecular weight polystyrene in 2-butanone to determine the effect of long-range interparticle interactions on the coupling between particle and polymer dynamics. Particles at concentrations of 1–10 wt % are well dispersed in the semidilute polymer solutions and exhibit long-range electrostatic repulsions between particles. Because the particles are comparably sized to the radius of gyration of the polymer, the particle dynamics is predicted to couple to that of the polymer. We verify that the polymer structure and dynamics are not significantly affected by the particles, indicating that the particle–polymer coupling does not change with increasing particle loading. We find that the coupling between the dynamics of comparably sized particles and polymer results in subdiffusive particle dynamics, as expected. Over the interparticle distance, however, the particle dynamics is hindered and not fully described by the relaxation of the surrounding polymer chains. Instead, the particle dynamics is inversely related to the structure factor, suggesting that physical particle–polymer coupling on short length scales and interparticle interactions on long length scales both present energetic barriers to particle motion that lead to subdiffusive dynamics and de Gennes narrowing, respectively.

Nanoscale Particle Motion in Attractive Polymer Nanocomposites

“…time of BL. The response at longer times would be similar to the behavior of concentrated NPs in non-attractive and entangled polymer solutions [47].…”

Differential dynamic microscopy of bidisperse colloidal suspensions

“… 13 , 35 Careful analysis of the residuals of a stretched exponential and a double exponential fit can distinguish between these decays. 39 For mixtures of particles of comparable size, the distribution of particle sizes will manifest as a polydispersity term, which can be captured by fitting a cumulant form to the intermediate scattering function. 19 …”

Intermediate scattering functions of a rigid body monoclonal antibody protein in solution studied by dissipative particle dynamic simulation

“…By taking advantage of the spin procession of a neutron in a magnet field, it can probe the time scale from several picoseconds to hundreds of nanoseconds with the length scale from a few angstroms to tens of nanometers. Owing to the large time and length scales it can probe, it has been used in many scientific areas including material sciences, 2,3 liquid physics, 4–6 glass transitions, 7,8 polymer dynamics, 9–11 and biological systems, 12 especially protein clusters 13–16 and protein internal motions. 17–22 Due to the interest in understanding the relationship between protein motions and its functionalities, protein internal motions are intensively studied by NSE in the past decade.…”