In a recent paper, we introduced a regularization (ensuring smooth dynamics) of the non-smooth Ianniruberto-Marrucci correction to convective constraint release (CCR) relaxation kinetics in the Rolie Poly model. However the choice of regularization parameter - and its quantitative impact on model predictions - has not yet been established. In this model, we provide scaling laws and heuristic arguments to inform the selection of regularization parameter in future studies. This work does not physically validate the Ianniruberto-Marrucci correction - much work is still needed to understand the physics of CCR in reversing flows - but it provides a valuable stop-gap, and we expect that our regularization scheme and scaling analysis should be transferable to future variations of physically-informed CCR corrections that may arise.
Accepted for Publication in Rheologica Acta - publication link will be posted soon.
The Poisson Renewal model was first introduced more than 30 years ago. The model is remarkably successful for comparisons to experimental data, but it requires a bit of expertise to understand and implement correctly. In this paper, we dramatically lower the barriers to deployment by (1) simplifying the model to an analytic solution and (2) providing a python script for automated parameter fitting to experimental data.
https://www.sciencedirect.com/science/article/pii/S0377025724001599
This project also features professor Jonathan Peterson - brother to Joseph Peterson - as a co-author. A short story of the project and their collaboration can be found here.
The rheology of living polymers, such as wormlike micelles, have been studied for over three decades. In that time, there have been many models developed to solve (or approximate) for linear rheology - however none of these methods gives access to fully converged predictions free of uncontrolled approximations, and as such they all leave residual sources of unquantified uncertainty in their predictions. In this paper, we show that a simple Fourier series expansion leads to a numerical method that is easy to implement and fast to compute, leading to the first "ground truth" calculation and a preliminary assessment of parameter errors in other modeling approaches.
The Peterson group has published its first student paper in JOR with Charlie Drucker as the lead author. In this work, we take a close look at the Rolie Poly model, a popular model for entangled polymer systems; we demonstrate and explain conditions under which the Rolie Poly model (as originally published) violates the laws of thermodynamics and propose a simple correction to the model. We hope that this work allows the Rolie Poly model to be used confidently in the future, resolving any lingering uncertainty about thermodynamic violations