(4hu) Molecular-based modeling of polymer dynamics for material design and processing

My research group will concentrate on mesoscale models for polymer dynamics and rheology. Although the polymer industry has been established for many decades, our understanding of the fundamental relations between polymer chemical composition and the properties of the final product is not complete. While we currently have decades of atomistic and molecular studies, the industry still relies on quasi-phenomenological approaches in practical applications. The reason is the lack of intermediate mesoscale models that connect molecular details and macroscopic properties. Due to molecular-level models' complexity and numerical cost, it is hard to apply them directly to real materials. For example, it is frequently impossible to simulate real molecular weights of polymers or nanoparticles of real sizes.

Recently, the slip-link model, a novel computational mesoscale method for the rheology of entangled polymers, grew from a fundamental concept to a tool capable of handling industrial-grade polydispersities and suitable for polymer processing optimization. Moreover, the model’s flexibility allowed it to be extended to crystallizing polymers. During this work, insights into crystallite network structure and the role of short-chain branching during crystallization were made through model interpretation of rheology of crystallized polymers. Building upon my experience with the slip-link model, my group will seek to gain more insights into molecular details and mechanisms from rheology, mechanical testing, and other experimental tools. Building mesoscale models requires a foundation of molecular and atomistic models, while comparison to experimental observations may require continuum-level descriptions or computation fluid dynamics methods. Therefore, my group will be a multi-scale modeling group with an accent on the mesoscale part. Based on my expertise, I identified the following three starting research areas:

• further rheological investigation of role SCB, molecular weight, crystallization conditions on crystallite structure during quiescent and flow-induced crystallization of industrial and lab-grade polymers.
• multi-scale simulation to explore the link between processing conditions and product properties for optimization of 3D printing, fiber blowing, and other industrial processes
• mesoscale modeling and extension of the slip-link model to nanocomposites to investigate the effect of rubber reinforcement by nanoparticles, such as Carbon Black, used in consumer rubber products

The goal of these research projects is to strengthen our understanding of material structure-property relations. For my group, contacts with experimental rheologists and polymer characterization specialists are essential. Specific attention will be given to projects with sustainable, renewable, or otherwise eco-friendly aspects.

Teaching Interests:

I am prepared to teach core chemical engineering classes like Transport Phenomena, Thermodynamics, and Statistical Mechanics, both at graduate and undergraduate levels. In addition, I have experience teaching polymer science, polymer rheology, or soft matter modeling class.

Selected Publications:

1. M Andreev, GC Rutledge, A Slip-link Model for Rheology of Entangled Polymer Melt with Crystallization. Journal of Rheology, 64, 213–222 (2020).
2. M Andreev, DA Nicholson, A Kotula, JD Moore, J den Doelder, GC Rutledge. Rheology of Crystallizing LLDPE. Journal of Rheology, 64, 1379–1389 (2020).
3. S Srivastava, M Andreev, AE Levi, DJ Goldfeld, J Mao, WT Heller, V Prabhu, JJ de Pablo and MV Tirrell, Gel Phase Formation in Dilute Triblock Copolyelectrolyte Complexes, Nature Communications, 8, 14131, 2017
   4. M Andreev, JD Schieber, Accessible and Quantitative Entangled Polymer Rheology Predictions, Suitable for Complex Flow Calculations, Macromolecules, 48 (5), 1606-1613, 2015
   5. M Andreev, RN Khaliullin, RJA Steenbakkers, JD Schieber, Approximations of the discrete slip-link model and their effect on nonlinear rheology predictions, Journal of Rheology, (57), 535-557, 2013