Modeling of Branched Thickening Polymers under Poiseuille Flow Gives Clues as to how to Increase a Solvent Viscosity

TL;DR

This study uses simulations to understand how branched polymers increase solvent viscosity under flow, revealing factors like polymer clustering and bonding strength that influence viscosity enhancement.

Contribution

It introduces a predictive model linking polymer structure and interactions to viscosity, aiding the design of effective viscosifying agents.

Findings

Polymer clustering raises viscosity significantly.

Bonding interaction strength strongly influences viscosity.

Scaling relationships enable better polymer design.

Abstract

The viscosity enhancement of a solvent produced by the addition of thickening branched polymers is predicted as a function of polymer concentration, branch length and persistence length, and strength of the covalent bonding interactions. Non equilibrium, stationary state Poiseuille numerical simulations are performed using the dissipative particle dynamics model to obtain the viscosity of the fluid. It is found that the clustering of the polymers into aggregates raises the viscosity and that it is more strongly affected by the strength of the bonding interactions. General scaling relationships are found for the viscosity as a function of the variables studied, which are expected to be useful for the design and synthesis of new viscosifying polymers. It is argued that our results can be applied to aqueous thickeners, of importance for colloidal fluids such as paints and coatings, and also for nonpolar fluids such as supercritical CO2, which is a promising non hydraulic fracking fluid also useful in enhanced oil recovery.