People
Michael O'Reilly
PhD Candidate
B.S. Materials Science and Engineering, Rutgers University, 2009
M.S. Materials Science and Engineering, University of Pennsylvania, 2011
LRSM 231
215-898-2700
morei@seas.upenn.edu
LinkedIn profile: http://www.linkedin.com/pub/michael-o-reilly/5b/336/689
RESEARCH TOPICS
(1) Nanoparticle Dispersion Effects on Ion Transport in Single-ion Conducting Nanocomposites
Polymer electrolytes based on poly(ethylene oxide) (PEO) and lithium salt complexes have hit an ionic conductivity ceiling without the addition of solvents or low molecular weight plasticizers—both of which make the intended solid polymer electrolytes more liquid-like. Nanocomposites present an opportunity to improve ion transport without sacrificing mechanical properties. Functionalization of silica nanoparticles to encourage favorable interaction with the host ionomer might facilitate ion conduction at the interface of the particle and polymer. The type of functional group is critical in determining how the nanoparticle will disperse and interact with the host ionomer. Highly flexible poly(ethylene glycol) brushes enhance segmental dynamics at the ionomer interface, while the nanoparticle body contributes rigidity to the nanocomposite.
(2) Morphology of Single-Ion Conducting Copolymers and Blends
Single-ion conductors are polymers with one ion covalently bound to the chain while the counter-ion is free to dissociate. Single-ion conductors have high Li transference numbers, but strong coulombic attraction between ions cause ion clustering which reduces conductivity and slows neighboring PEO segments.
In an attempt to improve Li+ mobility, PEO was copolymerized with PTMO to synthesize a multiblock copolymer single-ion conductor comprised of an ion solvating block and a low Tg block1. These experiments concluded that the benefits of adding highly flexible PTMO blocks were outweighed by the pitfalls of PTMO’s low dielectric constant. PTMO poorly solvates ion pairs, leading to more extensive aggregation and ion crowding in the PEO phase.
In a project that helped inspire the nanocomposite research above, the effects of oligomeric PEG on ionic aggregation were characterized by X-ray scattering and FT-IR 2. The results indicated that plasticizer contributes to the dissolution of aggregates by improving the segmental dynamics and depressing Tg.
Finally, single-ion conducting siloxanes were grafted with bulky, charge delocalized phosphonium salts and PEG segments. In these ionomers, low glass transition temperatures are maintained even at high ion contents. X-ray scattering experiments find no evidence of ionic aggregation enabling constant ionic conductivity across all ion contents3.
PUBLICATIONS
[2] Masser, H.; O’Reilly, M. V.; King, D. R.;; Colby, R. H.; Winey, K. I.; Painter, P.; Runt, J., “Influence of Plasticizer on Ion Aggregation in Single-ion Polymer Conductors,” In preparation.
[3] Liang, S.†; O’Reilly, M.†; Choi, U. H.; Bartels, J.; Chen, Q.; Runt, J.; Winey, K.I.; Colby, R. H., “High Ion-Content Siloxane Phosphonium Ionomers with Very Low Tg,” Macromolecules, to be submitted.
†indicates equal contribution
COMMUNITY OUTREACH
(1) FIRST Robotics
For Inspiration and Recognition of Science and Technology (FIRST) Robotics is a high school program designed to generate extracurricular interest in STEM fields. High school teachers, science and technology professionals, corporate sponsors, parents, and college students collaborate to educate, supervise, and inspire high school students while embracing the core value of FIRST, gracious professionalism. I mentor two FIRST teams specializing in strategies for design, build, and gameplay. Cold Fusion from Immaculata High School in Somerville, NJ is a 10 year veteran team. I am most proud of their longevity as an award winning, academically-oriented, extracurricular activity. The BambieBotz from St. Hubert’s High School for Girls in Philadelphia, PA was a rookie team in 2013. Despite their inexperience, the students’ performance and attitude won them the Rookie All-Star award for the Mid-Atlantic Robotics Region in 2013. We will carry that excitement into next season.
(2) Graduate Student Engineering Group (GSEG)
GSEG serves the school of engineering and applied science graduate community to make a student’s time at Penn as rewarding as possible from both a social and professional standpoint. I have served three years with GSEG in the following roles: GSEG President, GSEG Treasurer, and representative for Materials Science & Engineering.
I have overseen:
- Funding and planning of social and cultural events
- Selection of Engineering liaisons to sit on Penn’s committees
- Funding partnerships with: student groups centered around the advancement of women in science, advocacy for government sponsored research funding in science, graduate research symposia, Masters student professional development and readiness events