IRG 2 Members

Tim Manganello/BorgWarner Department Chair

arruda@umich.edu

The Arruda group specializes in theoretical, experimental, and computational polymer mechanics at the meso- and macro scales, including viscoplasticity theory, finite element modeling, and finite deformation thermomechanical characterization. Her group is building multi- scale constitutive models of CAN networks in collaboration with the Kieffer and Mao groups.

Professor of Materials Science and Engineering

kieffer@umich.edu

The Kieffer group uses inelastic light scattering, dielectric impedance spectroscopy, molecular dynamics (MD) simulations to study the dynamic response of several vitrimer systems to thermo-mechanical stimuli. In collaboration with Kim, Pena-Francesch, and Zhang we develop new vitrimers in which we can control the crosslink density and steric functionality. We coordinate property measurements with Arruda and Pipe, develop a new phenomenological theory alongside Arruda and Mao, and identify reaction mechanisms jointly with Sundararaghavan and Zimmerman.

Director Academic Programs

jinsang@umich.edu

The Kim group conducts rational molecular design and chemical synthesis of functional organic and polymeric materials. They are pursuing a novel polymerization scheme to achieve fully recyclable polymeric materials by polymerizing oligomers via dynamic covalent bonding. This effort to develop fully recyclable and self-healable commodity polymers involves collaborations with Kieffer, Zhang, and Zimmerman for characterization, chemistry, and computation.

Professor of Physics

maox@umich.edu

The Mao group has expertise in theoretical and computational soft matter, mechanical metamaterials, topological mechanics, and statistical mechanics. Her group works closely with everyone in IRG2 to establish the theoretical foundation for temperature-dependent viscoelasticity of CANs and with this knowledge design novel metamaterials realizing shape transformation and non-Hermitian dynamics using CANs.

Assistant Professor of Materials Science and Engineering

abdon@umich.edu

The Pena-Francesch group has expertise in bio-inspired self-healing polymers and soft matter engineering. In the MRSEC, they work on the design, synthesis, and multiscale characterization of elastomers and thermosets with associative/dissociative dynamic covalent bonds to regulate their network properties and enable their recycling, and life-cycle management. His group collaborates with theory (Arruda, Kieffer, Mao), simulation (Sundararaghavan, Zimmerman), synthesis (Kim, Zhang), and manufacturing groups (Sodano, Waas) to optimize bond exchange kinetics and bulk properties.

Associate Dean

pipe@umich.edu

The Pipe group has experience in techniques for thermal transport measurement and the design of materials for particular thermal properties. His group works with synthesis experts (Kim, Zhang) and computational experts (Kieffer, Sundararaghavan) to connect bond topologies to thermal transport properties and to determine the fundamental capabilities and limitations of CANs for heat flow regulation.

Professor of Aerospace Engineering

hsodano@umich.edu

The Sodano groups specializes in composite materials and structures, multifunctional materials, nanocomposites, nanotechnology, functional materials, interfaces, self-healing polymers, and energy harvesting. Collaborating with Zhang and Zimmerman, his group is developing highly reactive CAN chemistries for recoverable additive manufacturing. Jointly with the Kieffer group, he is characterizing the viscosity and cure rate during printing, as well as evaluating the properties of the printed materials.

Professor of Aerospace Engineering

veeras@umich.edu

The Sundararaghavan group employs molecular dynamics (MD) simulations to inform constitutive models of dynamically cross linked vitrimers in collaboration with Arruda, Kieffer, Mao, and Zimmerman. He developed a method to simulate dynamic cross-linking reactions using a topological reaction scheme. He studies how relative density of permanent vs. dynamic crosslink bonds and inert additives affects the creep resistance of vitrimers, partnering with experimental efforts of the Pena-Francesch, Sodano, Waas, and Zhang, groups.

Felix W Pawlowski Collegiate Professor

awaas@umich.edu

The Waas group develops multiscale constitutive models that allow one to establish links between the evolution of thermomechanical properties and fundamental deformation mechanisms. He performs mechanical characterization of fiber reinforced CAN composites, including measurements of fracture toughness as a function of environment, damage state and healing cycles. The development of CAN-specific multiscale mechanics models is achieved in collaboration with the Arruda, Kieffer and Sundararaghavan groups.

Professor of Chemistry/Chair

(University of Colorado Boulder)

Wei.Zhang@colorado.edu

The Zhang group has expertise in the synthesis and characterization of CAN materials. Here his group focuses on intrinsically charged ionic CANs (ICANs), studying their structure-property relationship, malleability, repairability, recyclability, etc. Along with Kim and Pena Francesch, he synthesizes novel CAN materials for further study by other IRG members. He collaborates with Kieffer regarding the dielectric and dynamic mechanical response, with Mao and Arruda on formulating new viscoelasticity, with Sundararaghavan on the creep resistance, and with Zimmerman accelerating the reactivity of ICANs.

Professor of Chemistry

paulzim@umich.edu

The Zimmerman group develops first-principles calculation based computational methods for the investigation of molecular reaction pathways. In this project he investigates the thermomechanical stimulus induced reactivity response of newly designed CAN candidate materials using the growing string method, informing the molecular designs by the Kim, Pena- Francesch, and Zhang groups. The focus is on tunability of the bond-breaking and forming processes, providing predictions that are validated by the Kieffer and Pipe groups.