W911NF-12-R-0011-03: Controlling Sequence in Precise Semiconducting Polymers
Abstract
Over the past 10 years, chain-growth polycondensation reactions have emerged as a powerful tool to control molecular weight and polydispersity in pi-conjugated polymers. This effort seeks to now combine these chain-growth methods with the concept of monomer sequence control to explore how polymer microstructure influences solid-state organization and bulk properties in precise functional materials. Because bulk properties and solid-state behavior is tunable through precise microstructure control, success of this effort may render novel semiconducting materials with a wide array of physical and chemical properties. To achieve the aforementioned objective, research efforts will focus on: (1) investigating main-chain sequence control. Specifically, this research aim will explore the group 16 heterocycles to examine how heteroatom manipulation alters the properties and behavior of pi-conjugated macromolecules; (2)side-chain engineering for sequence control. This aim will specifically explore how alternating electron-rich and electron-poor groups on the periphery of the main-chain can be used to manipulate chemical and physical properties of the materials. Polymers where the main-chain is kept constant and the side-chain sequence is modified will be investigated first. Manipulation of both the side-chain and main-chain units will then be explored to provide a further degree of control; (3) investigating the limits of chain-growth polymerization as catalyst association to the growing polymer is crucial to achieving precision in these reactions. This research aim will explore whether there is a limit to the number of sequenced monomers that can undergo a controlled polymerization. Monomer characterization will be carried out by Nuclear Magnetic Resonance (NMR) and Mass Spectrometry. The resultant sequenced polymers will be characterized structurally via NMR, gel permeation chromatography, cyclic voltammetry, fluorescence spectroscopy, UV-vis spectroscopy, thermal gravimetric analysis and differential scanning calorimetry. To probe the polymers nanostructure properties, atomic force microscopy, electron microscopy, and advanced X-ray scattering will be employed.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 12, 2017
- Source ID
- W911NF1610053
Entities
People
- Kevin J T Noonan
Organizations
- Army Contracting Command
- Massachusetts Institute of Technology
- United States Army