(6hk) Reconfigurable Polymers for Advanced Materials Applications

Research Interests: The overwhelming majority of the synthetic polymers we encounter in our daily lives are static. That is, their chemical structure and physical properties change minimally (if at all) from the moment they are synthesized until well after they are discarded. A recent major breakthrough in polymer science has been the development of dynamic covalent networks. While these materials can be reprocessed and healed, they rely on reversible isodesmic reactions and there is by design no net change in the material properties. The inventions of polymeric materials that can evolve in both evolve in both chemical structure and materials properties would present an amazing opportunity. Imagine for instance, soft clothing that could morph in to hard armor, or a tough plastic package that can be degraded and recycled to make a rubber ball.

The design of these reconfigurable polymers requires both the development of a new synthetic toolkit and a deep fundamental understanding of fundamental polymer structure-property relationships. My research aims to directly address this challenge, by developing new approaches to synthesize and study new polymers with dynamic topologies.

Successful Proposals:

1) "Insight into the Nanoscopic Structure of Bio-Inspired Polymeric Materials for Diverse Applications” (Advanced Photon Source General User Proposal, 2018)

2) “Biobased and Degradable Polyurethane Foams” (BASF 150^th Anniversary Science Competition, 2015)

3) “Sustainable and Recyclable Polyurethane Foams” (DOW Sustainability Innovation Student Challenge Award 2015)

4) High Performance Polymeric Materials from Renewable Resources (University of Minnesota Doctoral Dissertation Fellowship Proposal, 2015)

Postdoctoral Projects: Institute for Molecular Engineering, The University of Chicago (Advisor: Professor Stuart J. Rowan). Project Titles: 1) Synthesis of Dynamic and Stimuli–Responsive Liquid Crystal Elastomer Networks 2) Tuning Material Properties in Metallo–Supramolecular Polymers

PhD Dissertation: Department of Chemistry University of Minnesota, Twin Cities Advisor: Professor Marc A. Hillmyer) Title: High Performance Polymeric Materials from Renewable Resources

Research Experience: My research focuses on the development of new classes of soft materials utilizing polymers with dynamic covalent and non-covalent bonds. My overarching goals are to make and study polymers that can evolve or efficiently degrade in response to stimuli. In my PhD research, I worked to develop new high performance degradable materials from renewable monomers. Specifically, I collaborated with synthetic biologists to create an efficient semisynthetic process to produce a renewable monomer from sugar. I then went on to investigate the use of this monomer to in tunable elastomers, tough plastics, and chemically recyclable foams.

In my postdoctoral research, I synthesized and studied stimuli-responsive networks containing metallotropic or thermotropic liquid crystal mesogens. Specifically, the liquid crystal components are embedded in a dynamic covalent network, which makes the materials inherently healable (under light or heat) and reprocessable. I used these networks to create composites capable of reversibly actuating and folding in complex patterns. Ultimately the end goal of this project is to facilitate the design of ‘smart’ materials necessary for the development of truly soft robots. In a second project I have been studying the impact of binding metal and counter ion on the phase behavior and physical properties of metallo–supramolecular polymers. Similar to a block polymer, the non-metallated prepolymer tends to phase-separate on a length scale of several nanometers, due to the chemical incompatibility of the polymer spacer and metal-binding endgroups. However, the addition of metal leads to complex phase behavior that evolves over time and influences the mechanical and rheological properties of the material. I anticipate that the fundamental understanding of structure property relationships elucidated will help guide the design of new responsive and structurally dynamic materials.

Future Research Directions: As an independent investigator, I will study the impact polymer microstructure has on bulk materials properties. Initial investigations in the Schneiderman laboratory will consist of three aims:

(1) Development of new synthetic procedures that enables the production of precision polymers.

(2) Synthesis and characterization of novel structurally dynamic polymers

(3) Design of high-value degradable materials for applications in agriculture, medicine, and space exploration

This work will require a multidisciplinary approach, combining my PhD work in design and synthesis degradable polymeric materials with my postdoctoral work in studying dynamic covalent and supramolecular materials

Teaching Experience: I have gained extensive experience teaching and mentoring at all levels. While an undergraduate I was a teaching assistant (TA) for two different lab courses, Introduction to research and General Chemistry. I also to helped develop some of the first laboratory exercises for the multidisciplinary course Biomass Gasification for Alternative Energy. During my Ph.D. at University of Minnesota, I served one semesters as a teaching assistant for Advanced (Writing Intensive) Organic Chemistry Lab and also worked for two semesters developing polymer laboratory experiments for the undergraduate organic chemistry teaching lab (two of these experiments have been published in the Journal of Chemical Education). While a postdoc at the University of Chicago I volunteered as a guest lecturer for the course Polymer Synthesis (MENG 27320). In this role I was responsible for writing problem sets, assigning readings, teaching several lectures.

In addition to these teaching experiences, I have participated in a broad variety of outreach programs throughout my career. As an undergraduate I helped coordinate the Youth program Science Sensations which consisted of conducting biweekly hands on chemistry and physics experiments with primary students in rural schools. As a graduate I helped to found Science for All, a science outreach program for urban teens. In addition, I had the privilege to mentor several outstanding undergraduate and high school students both at UMN (8 undergraduates) and the University of Chicago (5 undergraduates; 2 high school students).

Teaching Interests: My teaching interests include the central courses in polymers – Polymer Science and Engineering and Polymer Physics. I am also interested in teaching Reaction Kinetics, Biomolecular Engineering and courses on materials characterization techniques.

Representative Publications:

1) Schneiderman, D. K., Ting, J. M.; Purchel, A. A., Miranda, R. Jr., Tirrell, M. V.; Reineke, T. M.; Rowan, S. J. Open-to-Air RAFT Polymerization in Complex Solvents (From Whisky to Fermentation Broth) ACS Macro. Lett 2018, 7, 406-411

2) Schneiderman, D. K.; Hillmyer, M. A. 50^th Anniversary Perspective: There is a great future in sustainable polymers Macromolecules 2017, 50, 3733-3749

3) Zhang, J.^*; Schneiderman, D.K.^*; Li, T.; Hillmyer, M. A. Bates, F. S. Design of Graft Block Polymer Thermoplastics, Macromolecules 2016, 49, 9108-9118 [*First authorship shared]

4) Schneiderman, D.K; Vanderlaan, M.E.; Mannion, A. M.; Panthani, T. R.; Batiste, D.C.; Wang, J. Z.; Bates, F. S. Macosko, C.W.; Hillmyer, M.A. Renewable, Chemically Recyclable Polyurethanes ACS Macro Letters, 2016, 5 (4), 515-518

5) Schneiderman, D.K; Hillmyer, M.A. Aliphatic Polyester Design Macromolecules 2016, 49(7), 2419-2428

6) Schneiderman, D.K.; Hill, E. M.; Martello, M.T.; Hillmyer, M.A. Poly(lactide)-block-poly(ε-caprolactone-co-ε-decalactone)-block-poly(lactide) copolymer elastomers Polymer Chemistry 2015, 6, 3641-3651

7) Xiong, M.*; Schneiderman, D. K.*; Bates, F. S.; Hillmyer, M. A.; Zhang, K. Scalable production of mechanically tunable block polymers from sugar PNAS 2014, 111 (23), 8357-8362 [*First authorship shared]

8) Schneiderman, D.K.; Gilmer, C.; Wentzel, M.T.; Martello, M. T.; Kubo, T.; Wissinger, J.E. Sustainable Polymers in the Organic Chemistry Laboratory: Synthesis and Characterization of a Renewable Polymer from δ-Decalactone and _L-Lactide J. Chem. Educ. 2014, 91 (1), 131-135