With funding from the Polymers Program of the Division of Materials Research, Professor John B. Matson of Virginia Tech and Prof. Ronit Bitton of Ben-Gurion University in Israel lead a team that is creating new polymers that take on a conical shape. How cone-shaped polymers behave and interact in solution is currently unknown because methods to synthesize these polymers were only recently developed. This work is important because polymers that interact in water to form aggregates on the size range of 1-100 nanometers are used in a variety of applications, but fundamental studies on how cone shape influences aggregate shape and size are lacking. The research team will rely on an approach that connects polymer synthesis, characterization of nanometer-scale aggregates, and computer simulations of aggregates to generate theories describing how these unique polymers behave in water. Collectively, these efforts will advance the field of polymer self-assembly, offering potential benefits in the design of polymers for applications in biomedicine, catalysis, food science, and other areas. Due to the collaborative and cross-cultural aspects of this NSF-BSF proposal, this platform will be used to enhance scientific communication with assistance from the Virginia Tech Center for Communicating Science. Off-campus educational goals of this proposal focus on enhancing the Youth Experiencing Science (YES) program for 4th–8th graders in southwestern Virginia.
This NSF-BSF project focuses on tapered amphiphilic bottlebrush block copolymers (BCPs), which are graft polymers with high grafting density designed to take on an approximately conical shape. The work incorporates an integrated approach to the synthesis, characterization, and simulations of tapered bottlebrush BCPs. Synthetic efforts will rely on ring-opening metathesis (ROMP) grafting-through methods to make a wide range of tapered bottlebrush BCPs with variable degrees of polymerization for the backbone and side chains. The solution self-assembly of tapered bottlebrush BCPs will be systematically investigated using a range of characterization techniques including electron microscopy and small-angle X-ray and neutron scattering (SAXS, SANS). Modeling studies will include coarse-grained models, in a feedback loop, to explain the observed morphologies and suggest new tapered bottlebrush BCPs that could self-assemble into unique or unexpected solution morphologies. The central hypothesis for this project is that the cone angle of the tapered bottlebrush BCPs will influence self-assembled morphology and size distribution. Expected outcomes from this synthesis–characterization–modeling approach include discovering how cone angle influences polymer self-assembly, ultimately revealing new understanding of how polymer structure influences material properties. .
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
