John P. Ferraris - US grants

This proposal was received in response to Nanoscale Science and Engineering initiative, NSF 05-610, category NIRT. One objective of this work is to provide science and technology enabling eventual commercial production of carbon nanotube yarns and sheets having close to the mechanical, electrical, and thermal transport properties of the component individual nanotubes. The approach taken is solid-state processing, since this is the only method that is applicable for the ultra-long nanotubes needed for realizing the spectacular inherent properties of individual nanotubes. Another objective is to add higher levels of hierarchal assembly that are optimized for active device applications. While applications focus will be on artificial muscles, project advances will benefit diverse applications demonstrated for these nanotube yarns or sheets: light emitting diodes, organic and electrochemical solar cells, polarized sheet incandescent light sources, cold electron emission displays and lamps, transparent conducting applique's, thermal electrochemical harvesting, and yarn supercapacitors. The last objective of developing a rational synthetic route to carbon nanotubes of one type, by crystal-based reactions that are an alternative to poorly controllable gas-phase-based nanotube growth processes, will increase fundamental understanding of crystal-controlled solid-state polymerization reactions, chemical transformations dominated by three-dimensional covalent connectivity, and enable bulk property characterizations for nanotubes of one type.
Nano@Border, NanoScout, NanoExplorer, and NanoInventor programs will benefit minorities, very young students, the retired and unemployed, as well as encourage people with quite different backgrounds to work together on interdisciplinary teams in frontier areas. Project funding will expand these educational activities, and bring women and Hispanics to work on the project. Our project collaborations with Raytheon, Lockheed Martin, Nokia, the NASA Ames Center for Nanotechnology, the Naval Undersea Warfare Center, Carbon Nanotechnologies Inc., Hyperion Catalysts International, Eeonyx Corporation, and other companies will both accelerate project progress, and help provide clear paths for commercialization of project discoveries.

0933563
Ferraris


This NSF award by the Chemical and Biological Separations program supports the work by Professor John P. Ferraris, Kenneth J. Balkus, Jr., and Inga H. Musselman at the University of Texas at Dallas to design, fabricate and test mixed matrix membranes (MMMs) for gas separations. This project will utilize novel materials that simultaneously target selected separations and provide improved interfacial contact with the polymer matrix. We have discovered that high loadings of nanoporous metal-organic frameworks (MOFs) in polymers can provide the long sought after breakthrough technology. MOFs offer some of the highest surface areas ever reported as well as the selective adsorption of gases involved in industrially important separations including CO2, CH4, O2, and N2. Many of these metal-organic frameworks have exceptional thermal and chemical stability such that MOFs could be competitive with zeolites for commercial separations. This novel class of materials has enabled us to fabricate MMMs with unprecedented loadings [>80% (w/w)], which we believe is the key to finally realizing the promise of mixed-matrix membranes for gas separations.

The broader impacts of this project on energy and the environment include numerous tasks that will lead to the integration of research and multilevel education in the area of membrane science and novel nanomaterials. The success of this potentially high impact research effort will lead to significant benefits to society including replacement of energy-intensive separations with membranes resulting in both energy and economic savings. A strong educational component will coincide with the research activities that will engage students at both the graduate and undergraduate levels as well as students from underrepresented groups and women. The skills acquired by students during this project will enhance their preparation for careers in membrane engineering, nanotechnology, energy, and materials science. In addition to seminars and course development on membranes and their applications, we seek to engage students at all levels in the study of membranes and nanomaterials. We are also committed to high school student research experiences through a number of summer programs and anticipate that this project will also impact the community at large by educating our high school teachers and students.

With this award from the Major Research Instrumentation Program (MRI) that is co-funded by the Chemistry Research Instrumentation Program (CRIF), Professor Mihaela Iovu from University of Texas Dallas and colleagues A. Dean Sherry, John Ferraris, Dennis Smith and Jung-Mo Ahn will acquire a 500 MHz NMR spectrometer equipped with two probes. The proposal is aimed at enhancing research training and education at all levels, especially in areas such as (a) polythiophene-CdSe blends for bulk heterojunction solar cells, (b) perfluorocyclobutyl (PFCB) polymers for proton exchange membrane (PEM) fuel cells and gas separation applications, (c) fluorovinylene aryl ether telechelic polymers for thermal chain extension and tandem crosslinking, (d) lanthanide complexes and polymers as metabolic sensors for Magnetic Resonance Imaging, and (e) development of peptidomimetics for treatment of diabetes mellitus.

Nuclear Magnetic Resonance (NMR) spectroscopy is one of the most powerful tools available to chemists for the elucidation of the structure of molecules. It is used to identify unknown substances, to characterize specific arrangements of atoms within molecules, and to study the dynamics of interactions between molecules in solution. Access to state-of-the-art NMR spectrometers is essential to chemists who are carrying out frontier research. The results from these NMR studies will have an impact in synthetic organic/inorganic chemistry, materials chemistry and biochemistry. This instrument will be an integral part of teaching as well as research.

Ferraris, John
1403950
Novel Nanostructured Membranes for Gas Separations

Polymer membranes for gas pair separations exhibit an inverse relationship between gas selectivity and gas flux. Maximizing both would be a significant advance. The idea of combining the selective separation properties of porous inorganic materials with the processability of polymers has resulted in several advances. Nevertheless, it appears that the performance of such membranes has reached a plateau, and a new approach will be needed to achieve a revolutionary breakthrough in membrane-based gas separations. The PIs have discovered that membranes constructed from otherwise immiscible polymers can be engineered at the nanoscale through the addition of small amounts of porous nanoparticles.

The major limitation with current mixed matrix membranes (MMMs) for gas separations is their low gas flux, primarily due to the membrane thickness (>several tens of micrometers) that is required to accommodate the porous additives. Colloidal ZIFs with particle diameters of <60 nm will enable the selective polymer layer to be submicrometer in thickness, and the matrix-droplet geometry will increase the interfacial surface area by 50 to 100X compared to a layer-by-layer morphology, greatly increasing flux while maintaining superior permselectivity. In order to fully utilize this novel membrane architecture, a thorough understanding of the thermodynamic and kinetic factors that control the structure will also be researched.

Combining the selective separation properties of inorganic molecular sieves with the processability of polymers to form mixed-matrix membranes (MMMs) has resulted in several advances including the incorporation of porous additives such as metal organic frameworks (MOFs) and zeolitic imidazolate frameworks (ZIFs). The organic-inorganic hybrid nature of these additives has afforded improved interfacial contact with the polymer matrix, enabling very high loadings in the MMMs.

The PIs propose a unique membrane architecture comprising blends of otherwise immiscible polymers that can be engineered at the nanoscale through the addition of small amounts of ZIFs. By choosing component materials with appropriate interfacial/surface tensions, the ZIF nanoparticles localize at the interface between the polymers. This has the advantage of compatibilizing high performance immiscible polymers thus greatly expanding the number of polymer combinations that can be utilized.

The proposed research will develop membranes comprising thin, continuous ribbons of a highly selective polymer embedded in a discontinuous matrix of a second, highly permeable polymer, somewhat akin to the marbling in USDA Prime Beef. Such architectures will significantly improve the performance of membranes, especially by increasing flux and selectivity at lower additive loadings, thus reducing cost. This project on energy and the environment includes numerous tasks that will lead to the integration of research and multilevel education in the area of membrane science and novel nanomaterials. The replacement of energy intensive separations with membranes could result in economic savings. This level of structural control could also be potentially useful for fuel cell applications and other separations. Additionally, the strong educational component coinciding with the research activities will engage students at both the graduate and undergraduate levels, as well as students from underrepresented groups and women. The skills acquired by students during this project will enhance their preparation for careers in membrane engineering, nanotechnology, energy, and materials science. We are also committed to high school student research experiences and we anticipate that this project will also impact the community at large by educating our high school teachers and students.





SIGNATURE

Name: Rosemarie D. Wesson
Title: Program Director
Program: Chemical and Biological Separations


DATE: April 2014