(7cq) Engineering Precision Polymers for Advanced Materials Applications

Research Interests: A long-standing challenge in materials science is the development of functional materials with predictable emergent bulk properties. Soft materials, such as polymeric supramolecular assemblies, have unique properties including flexibility, self-organization, hierarchical structure, self‑healing, and stimuli‑responsiveness that make them ideal candidates for health, energy, and infrastructure related applications. In such systems, the polymer microstructure and architecture strongly affect material functionality. However, studying the static and dynamic properties of these complex macromolecules in bulk is challenging due to their inherent polydispersity. My research aims to directly address this challenge by developing new approaches to synthesize polymers with precise control over dispersity, sequence, and topology (e.g., star, comb, brush polymers) to elucidate the relationship between molecular-scale properties and macroscopic material response, with the overarching goal of enabling better predictions of structure and properties of polymeric materials.

Successful Proposals: NIH T32 Postdoctoral Fellowship – Trauma, Burn, Wound Healing; Oak Ridge National Laboratory, Spallation Neutron Source, SANS (2017); European Synchrotron Radiation Facility, Time-resolved SAXS (2017).

Postdoctoral Project: Polyelectrolyte Driven Complexation of Sequence Specific Polypeptides, Institute for Molecular Engineering, The University of Chicago (Advisor: Professor Matthew V. Tirrell).

PhD Dissertation: Synthesis and Supramolecular Assembly of Biomimetic Polymers, The Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign (Advisor: Associate Professor Charles M. Schroeder)

Research Experience: My research focuses on the development of new classes of soft materials by studying and engineering the effects of polymer sequence, composition, and topology on polymer structure and properties. In my PhD research, I studied the dynamic and elastic properties of branched polymers. Specifically, I developed a hybrid synthetic strategy to produce branched polymer architectures based on chemically modified DNA that enables precise control of backbone length and flexibility, as well as branch grafting density and chemical identity. Using this approach, I synthesized a variety of polymer architectures, including three-arm stars, H-polymers, graft block copolymers, and brush polymers and characterized their material properties using single molecule studies. [1-3] These studies have increased our understanding of the dynamic and elastic properties of industrially relevant branched polymer topologies.

In my postdoctoral research, I developed synthetic polypeptide sequences using solid-phase synthesis to precisely control polypeptide length and sequence to create alternating, block, and gradient polypeptide copolymers comprising charged, polar and aromatic amino acids. Using this approach, I studied the effects of sequence patterning on phase separation using a variety of microscopic and spectroscopic techniques, including optical microscopy, fluorescence spectroscopy, and nuclear magnetic resonance spectroscopy. In addition, I investigated their chain conformations in polyelectrolyte complexes using SAXS and SANS. This work holds the potential to develop fundamental understanding of complex biopolymer phase separation, impacting the design of novel functional biomimetic materials for a variety of applications in drug delivery, coatings, and reaction engineering in controlled compartments.

Future Research Directions: As an independent investigator, I will study the impact polymer microstructure has on bulk materials properties. Initial investigations in the Marciel laboratory will consist of three aims (1) synthesis and investigation of dynamic properties of sequence specific polyampholytes, (2) correlation of branch polymer microstructure and mechanical and rheological properties, and (3) microfluidic-directed assembly of charged polymers. This work will require a multidisciplinary approach, combining my PhD work in synthesis and directed-assembly with my postdoctoral work in characterization of bulk polyelectrolyte complexes.

Teaching Experience: During my Ph.D., I served two semesters as a teaching assistant (TA) for Molecular Genetics and was awarded the 2010 and 2011 List of Teachers Ranked as Excellent by the University of Illinois at Urbana-Champaign (UIUC). In my second semester, I was selected to lecture the honors section, which afforded me the opportunity to lecture weekly and prepare problem sets. Furthermore, I served as a guest lecturer for the course Polymer Science and Engineering (ChBE 456). In addition to my teaching experiences, I have made an ongoing effort towards the advancement of underrepresented groups in STEM fields. Throughout my graduate and postdoctoral career, I have participated in a broad variety of outreach programs ranging from hands-on experiments with primary school students to graduate level recruitment in engineering with the Multicultural Engineering Recruitment for Graduate Education (MERGE) program. In addition, I had the privilege to mentor several outstanding female undergraduate and graduate students, who are currently pursuing engineering careers at ExxonMobil and Intel and postdoctoral research in chemical engineering at MIT.

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

Selected Publications:

1. A.B. Marciel, D.J. Mai, C.M. Schroeder, “Template-directed synthesis of structurally-defined branched polymer architectures”, Macromolecules, 48, 1296-1303 (2015).
2. D.J. Mai, A.B. Marciel, C.E. Sing, C.M. Schroeder, “Topology-controlled relaxation dynamics of single comb polymers”, ACS Macro Letters, 4, 446-452 (2015).
3. J. P. Berezney*, A.B. Marciel*, C.M. Schroeder, O.A. Saleh, “Scale-dependent stiffness and internal tension of a model brush polymer”, submitted, (2017). (*co-first)
4. A.B. Marciel, M. Tanyeri, B.D. Wall, J.D. Tovar, C.M. Schroeder, W.L. Wilson, “Fluidic-directed assembly of aligned p-conjugated oligopeptide nanofibers”, Advanced Materials, 25, 6398-6404 (2013).
5. A.B. Marciel and C.M. Schroeder, “New Directions in Single Molecular Polymer Physics” Journal of Polymer Science, Part B: Polymer Physics, 51, 556-566 (2013).
6. K.T Nam, S.A. Shelby, P.H. Choi, A.B. Marciel, R. Chen, L. Tan, T.K. Chu, R.A. Mesch, B.C. Lee, M.D. Connolly, C. Kisielowski, R.N. Zuckermann, “Free-floating ultra-thin two-dimensional crystals from sequence-specific peptoid polymers”, Nature Materials, 9, 454-460 (2010).
7. A.B. Marciel, E.-J. Chung, B.K. Brettmann, L. Leon, “Bulk and nanoscale polypeptide based polyelectrolyte complexes” Advances in Colloid and Interface Science, 239, 187-198 (2016).
8. J. Vieregg*, M. Lueckheide*, A.B. Marciel, A. Bologna, J. Reyes, L. Leon, M. Tirrell, “Oligonucleotide-peptide complexes: phase control by DNA hybridization” in revision, (2017). (*co-first)