Cynthia J. Jameson, PhD - US grants

In this project supported by the Experimental Physical Chemistry Program of the Chemistry Division, Cynthia Jameson will study the dynamics of gases interacting with zeolites using 129Xe NMR spectroscopy, ab initio calculations of chemical shifts, and computer simulations. The project will look at elementary processes at surfaces, such as adsorption and diffusion, in order to gain a microscopic understanding of the sometimes complicated surface chemistry. The current effort will extend both simulations and experiments to more complex systems. %%% Microporous solids, such as zeolites, are widely used for a large number of applications, including heterogeneous catalysis, separations, oil recovery, and other industrial processes. Industrial processes which involve adsorption from gas streams with multiple components depend on the separation of these components through competitive adsorption on the catalytic surfaces. The results of this research project will aid in understanding these sorts of applied systems.

In this Faculty Early Career Development Award funded by the Experimental Physical Chemistry Program in the Chemistry Division, Lucio Frydman of the University of Illinois at Chicago will develop and apply new multidimensional NMR techniques to the analysis of complex solids. These new techniques will rely on non-Cartesian sampling of time-domain spaces which will shorten the duration of multidimensional NMR acquisitions and establish new correlations between spin interactions. These experiments will also focus on new methods of characterization of quadrupolar spins, which comprise a large majority of nuclides which play a key role in the structures of inorganic solid materials. The techniques will be applied to characterization of high performance ceramics used in the aerospace industry. The educational component of this program involves integrating state-of-the-art NMR analysis techniques into the undergraduate curriculum and establishing new courses in the graduate Analytical Chemistry program aimed at providing students with a practical background currently demanded by industry. NMR has proven to be a reliable and powerful diagnostic technique in the biomedical profession. Similar analysis of solids cannot currently be accomplished due to the different physical interactions in the solid phase. Professor Frydman will develop techniques that will permit characterization of solid materials such as high temperature ceramic fibers used in the aerospace industry.

9420458 Frydman This project focuses on nuclear magnetic resonance investigation of order and dynamics in liquid-crystalline polymers. These new materials play special roles in several structural and electronic applications. Their main characteristics are a strong affinity towards the formation of liquid-crystalline solutions, and an ability to retain these solution arrangements upon going into the solid state. This combination makes possible the generation of highly ordered macromolecular materials with valuable mechanical, thermal and non-linear optical properties. Further advances in the practical utilization of these polymers are intimately linked to understanding the ways in which chemical structures and external factors such as flow fields, can control their dynamics and orientations. These aspects are explored using state-of-the-art multidimensional nuclear magnetic resonance in both the liquid-crystalline and the solid phase, as well as gradient-based magnetic resonance microscopy methods. These experiments rely extensively on a specialized technology whose purpose is the characterization of local anisotropic environments at molecular and supramolecular levels. They involve the use of high-temperature dynamic-angle assemblies for studying molten thermotropics, of variable-angle spinning probeheads for solid-phase analyses of order and reorientations, and of rheo-imaging instrumentation for the investigation of flow in lyotropics. Using these techniques it will be possible to probe how local mesomorphic order in thermotropic liquid- crystals depends on chemical composition; how much of the liquid-crystalline order of these systems is preserved upon cooling them into glasses; how solid-phase chain dynamics affect the alignment of these polymeric glasses and what is their exact nature; and how different types of flow and diffusion impart a net anisotropy of solutions of liquid- crystalline polymers. An important aspect of these experiments is the ir reliance on the natural-abundance observation of 13C spins, a method that imposes no preconditions on the type or origin of the samples under study. Thus, the materials to be analyzed include homopolyesters with high melting temperatures, commercial thermotropic copolymers, complex molecular blends of liquid- crystalline and random polymers, and corrosive lyotropic solutions. %%% All these are highly relevant systems, whose better understanding should have a significant impact on their practical application.

With this award from the Chemistry Research Instrumentation and Facilities (CRIF) Program, the Department of Chemistry at the University of Illinois in Chicago will acquire a solid-state upgrade for a 500 MHz NMR Spectrometer. This equipment will enhance research in a number of areas, including a) studies of phospholipid bilayer phase transitions and lipid-protein interactions; b) solid phase synthesis of oligosaccharides containing the beta-mannoside and beta-rhamnoside linkages; c) studies of polymeric and inorganic materials; and d) investigations on the distribution and dynamical behavior of adsorbed species in microporous solids.

Nuclear Magnetic Resonance (NMR) spectroscopy is the most powerful tool 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 spectrometry is essential to chemists who are carrying out frontier research. The results from these NMR studies are useful in materials science and biology.

Professor Cynthia Jameson of the University of Illinois at Chicago is supported in the Experimental Physical Chemistry program to perform Nuclear Magnetic Resonance (NMR) studies utilizing Xenon atoms to probe environments difficult to study such as the interior of zeolites, polymers and biomolecules. Her goal is to use these experiments together with ab initio predictions of chemical shift parameters and more standard Monte Carlo statistical models to develop Xenon NMR as an exact quantitative method. Xenon NMR is widely used to study solid samples, but it has not yet been exploited to its full potential. For example, her group will develop the method for accurate determination of competitive adsorption of molecules in zeolite cavities, a key parameter in understanding the catalytic power of zeolites. The effect of counterions in cation-exchanged zeolites will be studied, as well as some kinetics and dynamical studies on these systems. The experiments will provide testing grounds for new theory - improving the potential surfaces between Xenon and coadsorbates (or the zeolite wall) as well as the statistical models for adsorption in zeolites. The experience with zeolites will then be applied to the problem of structure of liquids, polymers, and biological systems. Professor Jameson will conduct mainly theoretical studies analyzing Xenon NMR signals in cyclodextrin, polymers, polymer blends and in globular proteins such as myoglobin, with the goal of understanding the structures of these microheterogeneous chemical environments.

Nuclear magnetic resonance (NMR) is a chemical version of the more well-known medical method Magnetic Resonance Imaging (MRI). The use of NMR for understanding basic structural features of solids, liquids, and gases is increasing with the development of new techniques such as Xenon NMR, which has been used to study solid-state structures. The research is timely also due to the recent use of hyperpolarized Xenon for imaging (including clinical applications). In addition to interesting the catalysis community studying zeolites, the work will ultimately be of use in other applications of microporous solids such as separations. Professor Jameson is well known as an outstanding mentor of women and minorities in her laboratories.

The goal of the Women in Science and Engineering System Transformation (WISEST)
project, at the University of Illinois at Chicago (UIC), is to increase the number, participation,
and leadership status of women, majority and minority, in eleven science and engineering
(STEM) departments through institutional transformation. WISEST will use an innovative
approach of a network of faculty facilitators from all STEM departments working with
department heads and an executive committee of key administrators and a social scientist.
This network will carry out five integrated and mutually reinforcing strategies: warm the
climate and decrease the isolation of women STEM faculty; recruit minority women faculty
through an unique mentored postdoctoral program; transform STEM departments to foster
diversity and womens leadership; promote womens scholarship and teaching; and improve
the ability to track and report on gender equity. Proposed outcomes for STEM women
faculty include: increased numbers of majority and minority faculty; improved retention
rate; salary equity with men of similar accomplishments and productivity; increased
percentage of leadership positions; improved job satisfaction; and increased national visibility
for our scholars. The intellectual merit of WISEST is that it will assess the impact of
systemic change to erase gender stereotyping rather than individual remediation and it will
specifically extend the focus of action to include the postdoctoral level to recruit faculty. Its
broader impact will be the creation of a life-friendly work climate for all UIC faculty.
WISEST will share its experiences nationally, and serve as an exemplary model for fostering
gender equity and diversity in academe.

Proposal Title: Molecular Modeling of Ion Transport and Separation in Nanochannels
Proposal Number: CBET-0730026
Principal Investigator: Sohail Murad
Institution: University of Illinois Chicago


The objectives of the proposed research are to understand the general details of ion transport and the essential structural and dynamic characteristics for transport of charged particles through a nanochannel under passive, pressure-driven or electric field driven conditions, so as to improve controllability and selectivity. Biological ion channels are themselves nanofluidic devices; however, the level of complexity present in such channels obscures the properties that are the basic essentials of an ion-selective nanochannel. Ion permeation of nanochannels will be studied as a general phenomenon, starting with the simplest model for a nanochannel and increasing the complexity of the model in a stepwise manner by adding attributes that will permit answering some of the questions that are being asked about nanofluidic devices.. Simplified pore models permit investigation of the primary characteristics of a conduction pathway: the shape, radius, and length of the pore, the chemical (hydrophobic or hydrophilic) nature of the pore wall surface, its surface roughness and flexibility, the presence and distribution of surface charges, the presence of an external electric field.
Broader Impact: Recent advances in the fabrication of confined fluidic systems such as nanoscale lab-on-a-chip devices and nanofabricated pores raise fundamental questions about ion transport in nanochannels. Solvent slip along the hydrophobic walls of the carbon nanotube is controlled by fluid-wall interactions. Investigation of such slip flow behavior and other characteristics of flow in nanotubes can be vital for generating the high throughput rates required in nanofluidic devices employing carbon nanotubes. In addition similar issues play an important role in transport processes in biological membranes, and cellular functions. This research will provide training for undergraduate and graduate students and will prepare highly skilled technical personnel with broad knowledge encompassing engineering, chemistry, biology, and nanotechnology. The PIs have been actively participating in the WISEST (Women in Science and Engineering System Transformation) program at UIC and will continue those activities through this grant.