Acquisition of a 400-MHz Solid-State NMR Spectrometer for Investigations of Synthetic and Naturally Occurring Polymers

Iowa State University, Ames IA

Investigators

Abstract

The new 400-MHz solid-state nuclear magnetic resonance (NMR) spectrometer supported by this Major Research Instrumentation award will enable an interdisciplinary team of researchers at Iowa State University to characterize complex polymeric materials in unprecedented detail. Multidimensional NMR in particular will be applied to provide detailed and quantitative information on the chemical structure, conformations, inter segmental distances, and reorientations of molecules in disordered macromolecular solids. The insights obtained will be the basis for the rational design of improved materials and for controlling the interactions of macromolecular organic substances in the natural environment with contaminants and nutrients. Specifically, the new NMR instrument will enable the investigators to perform research on: 1) chain conformation, packing, and dynamics in amorphous synthetic polymers, and their effects on macroscopic materials properties, including physical aging; 2) the configuration and sequence distribution of polymers containing new polar, functionalized dienes; 3) nanometer-scale structures in technologically important heterogeneous polymer systems; 4) structure and dynamics in nano-composites of polymers with novel inorganic glasses of low glass-transition temperature; 5) the structure and improved properties of plastics from renewable resources; 6) the structure of soil organic matter, its formation, and its influence on the sorption of organic and inorganic contaminants; 7) mechanisms of carbon sequestration in soil, which can reduce atmospheric "greenhouse gases"; 8) the development of advanced, often multidimensional NMR pulse sequences to provide an "arsenal" for NMR analysis of organic solids with at least three-fold increased structural resolution. The diversity of the faculty collaborating in the use of this instrument will provide an excellent environment for students of chemistry, materials science, agronomy, and food science to learn and perform research in a stimulating interdisciplinary atmosphere. This award from the Major Research Instrumentation program to Iowa State University supports the acquisition of a 400 MHz Nuclear Magnetic Resonance (NMR) instrument. NMR is one of most powerful methods for analyzing complex organic materials. It uses the magnetic properties of the nuclei of many atoms. These nuclear magnets act as local "spies" reporting on their molecular environment, and they do so in response to radio-frequency pulses. These pulses can be designed to "tease out" specific information about the chemical structure, about nanometer-scale domains, or about motions of segments in the material under investigation. The new NMR instrument will help researchers to develop materials with tailored properties, such as less brittle biodegradable plastics, better membranes for use in fuel cells, strong plastics from renewable resources, improved adhesives, or lightweight materials providing increased fuel efficiency in vehicles. It will also enhance our understanding of how soil organic matter and fossil fuels are formed, and aid in the development of improved procedures for environmental clean-up and for the sequestration of "greenhouse gases" from the atmosphere. The diversity of the faculty collaborating in the use of this instrument will provide an excellent environment for students of chemistry, materials science, agronomy, and food science to learn and perform research in a stimulating interdisciplinary atmosphere.