Macroscopic Viscosity of Polymer Solutions from the Nanoscale Analysis

Abstract

The effective viscosity in polymer solutions probed by diffusion of nanoparticles depends on their size. It is a well-defined function of the probe size, the radius of gyration, mesh size (correlation length), activation energy, and its parameters. As the nanoparticle’s size exceeds the radius of gyration of polymer coils, the effective viscosity approaches its macroscopic limiting value. Here, we apply the equation for effective viscosity in the macroscopic limit to the following polymer solutions: hydroxypropyl cellulose (HPC) in water, polymethylmethacrylate (PMMA) in toluene, and polyacrylonitrile (PAN) in dimethyl sulfoxide (DMSO). We compare them with previous data for PEG/PEO in water and PDMS in ethyl acetate. We determine polymer parameters from the measurements of the macroscopic viscosity in a wide range of average polymer molecular weights (24–300 kg/mol), temperatures (283–303 K), and concentrations (0.005–1.000 g/cm3). In addition, the polydispersity of polymers is taken into account in the appropriate molecular weight averaging functions. We provide the model applicable for the study of nanoscale probe diffusion in polymer solutions and macroscopic characterization of different polymer materials via rheological measurements.

Correlating viscosity and molecular crowding with fluorescent nanobeads and molecular probes: in vitro and in vivo

“…Note that the Mark–Houwink equation scales the intrinsic viscosity with molecular weight, not the dynamic viscosity. Nevertheless, interested readers can find that the Mark–Houwink equation can be easily translated into a length-scale-dependent model if they find this more instructive [54,55]. These indicate a trend in both intrinsic and dynamic viscosity of glycerol less than Ficoll 70 less than Ficoll 400 (for example, comparing the dynamic viscosity measurements from the bulk ensemble experiments at 10% (w/v) indicates viscosity values of glycerol = 1.3 cP, Ficoll 70 = 2.1 cP and Ficoll 400 = 4.9 cP at room temperature, in comparison to water of 1 cP), so Ficoll 70 has a viscosity which is greater than that of glycerol by a factor of approximately 1.6, whereas the equivalent factor for Ficoll 400 is closer to approximately 2.4.…”

Correlating viscosity and molecular crowding with fluorescent nanobeads and molecular probes: in vitro and in vivo

“…Note, the Mark-Houwink equation scales the intrinsic viscosity with molecular weight, not the dynamic viscosity. Nevertheless, interested readers can find that the Mark-Houwink equation can be easily translated into a lengthscale-dependent model if they find this more instructive (55,56). These indicate a trend in both intrinsic and dynamic viscosity of glycerol < Ficoll 70 < Ficoll 400 (for example, comparing the dynamic viscosity measurements from the bulk ensembles experiments at 10% w/v indicates viscosity values of glycerol =1.3 cP, Ficoll 70 = 2.1 cP and Ficoll 400 = 4.9 cP at room temperature, in comparison to water of 1 cP), so Ficoll 70 has a viscosity which is greater than that of glycerol by a factor of ~ 1.6, whereas the equivalent factor for Ficoll 400 is closer to ~ 2.4.…”

Molecular Dynamics-Assisted Design of High Temperature-Resistant Polyacrylamide/Poloxamer Interpenetrating Network Hydrogels

“…In addition, compared to the single APAM solution, the viscosity of APAM/poloxamer dropped sharply (Figure S11). The viscosity of all materials decreased with an increasing shear rate, indicating that they have polymer properties [38,39]. Furthermore, SEM was used to study the differences between the three complexes.…”