(3h) Structure-Property-Dynamics Relationships in Polymer Nanocomposites

The utility of polymeric materials relies on our understanding of “structure-property” relationships. The ultimate translation to function in daily life is also dependent on understanding and commanding time-dependent behavior, such as the viscoelasticity and microscale structural dynamics. My research philosophy is rooted in exploring the continuum of “structure-property-dynamics” relationships in polymer nanocomposite (PNC) systems. The goal is to understand the interplay between dynamics of polymers and fillers at the micro and macroscale to generate design principles that control desirable mechanical properties in conjunction with hierarchical structure. Utilizing a multimodal experimental approach that combines rheology and scattering techniques, we resolve phenomena in model systems to satisfy basic curiosities and polymer physics queries. A specific focus is placed on in-situ testing environments to understand out-of-equilibrium behavior under external stimuli. The vision is to translate our renewed understanding and engineer materials with unique and beneficial properties for traditional applications in coatings and structural materials, with additional focus applied to utilizing and developing both practical and novel processing techniques.

These research interests fall at the intersection of physics, chemistry, and engineering while specifically focusing on the underlying role that polymers play in the utility of functional materials. Personally, I am inspired by our sustainable relationship with nature and I am passionate about positively impacting the world around us through translational research. Future work will steer the research program towards “green” approaches and emerging technologies such as processing of recyclable materials, renewable feedstocks, and lifecycle analysis of PNCs. The research program will strive to collaborate with industrial partners and user facilities at national laboratories (i.e. synchrotron facilities) in combination with diverse in-house characterization tools.

Research Experience

During my graduate research at UMass Amherst, I investigated the relationship between morphology and rheological properties of model PNCs fabricated by the self-assembly of block copolymers. We explored the the impact of nanoparticle content on phase behavior in systems assembled from triblock copolymer surfactants, utilizing in-situ X-ray scattering to correlate ordered phase transitions with liquid-solid transitions identified by shear rheology. The systematic study revealed the power of multimodal material characterization to understand the underlying physics of a model system. Early on, we became interested in bottlebrush block copolymers (BBCPs), densely grafted comb polymers with polymeric side chains attached to a linear macromolecular backbone. The novel architecture results in functional nanomaterials that rapidly self-assemble into well-ordered nanostructures. However, the mechanism behind the rapid self-assembly and a quantitative relationship between the architecture and the rheological properties, (critical to improve processing pathways and utilization of such materials) remained unanswered. We tackled the problems using high throughput X-ray scattering and shear rheology, leading to the development of an empirical model to describe the role that the hierarchical architecture plays on the relaxation dynamics. Valuable synchrotron beamtime was acquired at National Synchrotron Light Source II, Brookhaven National Laboratory (NSLS-II, BNL) through a user proposal that I prepared. The beamtime increased our data quality and advanced our understanding of the system. Such studies provided crucial insight into the rather fundamental physics of these materials and their valuable ability to rapidly self-assemble.

Now as a joint postdoctoral associate at Stony Brook University (SBU) and NSLS-II, I am deepening my expertise in synchrotron X-ray scattering and rheology with emphasis on the in-situ characterization of polymer structure and dynamics. This is an opportunity to conduct ground-breaking research in chemical engineering, soft matter physics, and X-ray science. I am leading a collaborative project with Henkel Corporation on developing “in-operando” X-ray photon correlation spectroscopy (XPCS) techniques to resolve out-of-equilibrium behavior in industrial 3D printed materials across a range of relevant length (nm to 100s of nm) and time scales (1 ms to 1000s of s). We have developed a platform to resolve spatial and time-resolved structural dynamics within 3D printed filaments to better understand the impact of the 3D printing process on the fundamental polymer physics at play during printing. Operation of this instrument at the beamline requires a solid understanding of the underlying theories as well as significant hands-on experience. I actively collaborate across the three arenas of academia, industry and national labs through our projects. Each group has a unique vision and means for impactful science, which fosters my passion for translational research. BNL has a strong initiative in additive manufacturing with particular focus on soft materials. I frequently collaborate with user groups conducting work at various beamlines, planning and performing in-situ experiments with their materials while addressing their scientific curiosities.

Teaching Interests

Each research experience has shaped my teaching interests and mentoring philosophy. My formal teaching engagements spans both the undergraduate and graduate levels. My first opportunity was TA-ing the introductory undergraduate chemistry course at Case Western Reserve University, part of the core engineering curriculum. As a graduate student, I sought out teaching experiences in polymer physics and laboratory characterization. I urged students to work together as they interacted directly with instruments and materials to reinforce classroom concepts. This “learn-by-doing” approach gave them tools to develop into successful independent researchers. I have continued the pursuit of teaching opportunities at SBU by guest lecturing the graduate-level polymer course on several occasions. In the future, I seek to apply my philosophy in a range of undergrad/grad level courses in polymer physics, advanced characterization, transport and polymer processing. The “hands-on” approach fuels my mentoring style. I focus on developing students from a novice to expert through practice by defining (and re-defining) research questions, designing (and re-designing) experiments while conducting independent research with me as a guide. I especially encourage learning through mistakes (which are inevitably made along the way). Teaching and mentoring are also a vital part of any collaborative research program. I am passionate about creating an interdisciplinary environment, as my research and teaching interests combine aspects of chemical engineering, materials science, synthetic chemistry, and applied physics. As engineers, we have a duty to tackle modern challenges beyond the laboratory and classroom. In addition to following inherent curiosity, I encourage students to work towards the betterment of our society through translational research, scientific communication, and community engagement. I strongly believe that the major role of my research and teaching program is to provide a platform for young scientists to develop skills necessary to be successful along their own career path. My ultimate goal is to mentor and develop the next cohort of leaders, continuing the cycle of impactful science for future generations.

Featured Publications (13 total, 4 first author, Google Scholar)

• Yavitt, B.M.; Salatto, D.; Huang, Z.; Koga, Y.; Endoh, M.; Wiegart, L.; Poeller, S.; Petrash, S.; Koga, T.; Revealing nanoscale dynamics during an epoxy curing reaction with X-ray photon correlation spectroscopy. Journal of Applied Physics, 2020, 127, 114701
• Yavitt B.M.; Fei H.; Kopanati G.N.; Winter H.H.; Watkins J.J.; Power Law Relaxations in Lamellae Forming Brush Block Copolymers with Asymmetric Molecular Shape. Macromolecules, 2019, 52, 4, 1557-1566
• Gai, Y.; Song, D.; Yavitt, B.M.; Watkins, J.J.; Polystyrene-block-Poly(ethylene oxide) Bottlebrush Block Copolymer Morphology Transitions: Influence of Side Chain Length and Volume Fraction. Macromolecules, 2017, 50, 1503-1511

Service & Outreach

• UMass Polymer Science Climate Committee - Member, Dept. of Polymer Science and Engineering, University of Massachusetts Amherst (2017 -2018)
• Facility Manager - X-Ray Scattering, GPC-MALLS, Dept. of Polymer Science and Engineering, University of Massachusetts Amherst (2016 – 2018)
• A Student-Led Program in Research and Education (ASPIRE), Dept. of Polymer Science & Engineering, University of Massachusetts Amherst (2014 – 2017)
• PSE Student Club - Vice President, Dept. of Polymer Science and Engineering, University of Massachusetts Amherst (2014)