Researcher(s)
- Kaveri Srivastava, Chemical Engineering, University of Delaware
Faculty Mentor(s)
- Dr. Arthi Jayaraman, Chemical Engineering, University of Delaware
Abstract
Thermally conductive materials (TCMs) are required for a variety of applications such as solar cells and batteries. Specifically polymer based TCMs exhibit favorable features like low density, high electrical and easier processability making them attractive for the above applications. However, past work has shown that polymeric TCMs have not exhibited high enough thermal conductivity needed for practical use. Hence, the goal of this army research office (ARO) supported collaborative MURI project is to develop design rules for polymeric materials that can exhibit high thermal conductivity (k) that could also be altered on demand using stimulus. Our hypothesis is that high k can be achieved in polymeric materials if we achieve long range crystallinity and have chemistries that exhibit enhanced molecular interactions leading to stiffness.
One class of the polymeric materials we are working with are block copolymers (BCPs). BCPs are macromolecules formed by linking two or more chemically distinct polymers. The classic linear BCP is a diblock copolymer whose melt phase behavior is well established in past theory and simulations. Going beyond the conventional BCPs our project incorporates monomer chemistries which exhibit directional interactions like Hydrogen (H)-bonding and -stacking, enabling improved backbone alignment and potentially long range positional and orientational order. My project focuses on molecular dynamics (MD) simulations that help us link design rules of such H-bonding BCPs to the extent of positional and orientational order in BCP bulk morphology. The first step in this project is to develop coarse-grained (CG) models for the BCPs being synthesized in our collaborators laboratories at the University of Florida. The CG model should capture effectively the directional H-bonding interactions between the monomer chemistries and the polymer chain level structural rearrangements in reasonable computational run time.
My poster shows the CG model development using ongoing single and two chain MD simulations. The next step will involve using this CG model to study multiple chains mimicking a melt of BCPs. Analysis of the simulation configurations will then tell us how the choice of BCP design impacts local positional order, orientational alignment of chain segment, macroscopic domain shapes, and roughness of interfaces between domains. These CG MD simulation configurations will then be back-mapped to atomistic resolution for thermal conductivity calculations in our collaborators’ laboratories at Carnegie Mellon University.