With this award, the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry is supporting Professor Todd Emrick of the University of Massachusetts Amherst to combine state-of-the-art elements of chemistry and nanoscale science to produce advanced structures, such as electronic devices, that aim to to be smaller, faster, more sensitive, more efficient, and more reliable than those on the market today. For example, polymers and inorganic nanoparticles, once considered separate topics, are blended in this work to make "hybrid structures", each component interacting with the other to produce striking effects. Professor Emrick's group synthesizes polymers ("soft materials") that markedly influence the surface electronic properties of metals (i.e., "hard materials") onto which they are coated. This ability of soft materials to dramatically change the properties of the materials they contact has profound implications for improving the efficiency of numerous devices, including solar cells that collect charge and generate power more efficiently than conventional structures. This project additionally seeks to understand how polymers interact with structures emerging from the latest developments in two-dimensional materials, including those composed of ultrathin layers of carbon, metals, and other elements. The project includes the participation of undergraduate researchers seeking to gain their first laboratory experience, and involves the development of "NanoDays" discussions for middle school and high school students, intended to convey the excitement of nanoscale chemistry to the next generation of researchers.
More specifically, the project is engaged in the synthesis of new functional polymer platforms for integration into nanoscale assemblies and hybrid materials structures. The polymers of interest are prepared and used for surface functionalization of metals and 2-D materials, including: 1) polymers with pendent dipoles, and 2) functional polymers tailored for interactions with 2-D nanoscale structures. The dipole-inducing groups fixed pendent to the polymer chains include zwitterionic substituents (hydrophilic dipoles), with preliminary results describing the impact of conjugated polymer zwitterions on metals, producing polymer solar cells with high power conversion efficiency (PCE) due to the effect of the polymers on high work function metal electrodes. These results translate to functionalized 2-D nanostructures, such as graphene and transition metal dichalcogenides (TMDCs), ultimately seeking polymer chemistry-enabled device enhancement. New synthetic zwitterionic polymers will delineate the effect of the pendent zwitterionic groups on underlying substrates, as distinct from polymer backbone characteristics, by comparing aromatic and aliphatic polymers having zwitterionic pendent groups. Augmenting the polymer zwitterions is a sulfur-rich polymer platform aimed to tailor electronic properties and result in novel architectures with improved device metrics.
