Adjunct and Associated Faculty

Tarek Agag

Research Associate Professor

Ph.D., Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, OH

 

James M. Anderson

Associate Faculty

Department of Pathology

Our research is directed towards developing a greater understanding of host/material interactions that comprise the inflammatory cell responses to biomaterials and to acquire fundamental knowledge and perspective necessary for the design of new materials. A wide variety of in vitro and in vivo techniques are utilized to study host/material interactions and these include confocal fluorescence laser microscopy, cell culture, and the rat cage implant system. Utilizing silane-modified surfaces, in vitro studies focus on the material surface dependence of cytokine-induced foreign body giant cell formation and accompanying cystoskeletal/adhesive structural reorganization. Studies on the long-term biodegradation of elastomeric biomaterials are directed toward developing a fundamental understanding of biocompatibility and biostability/biodegradation of polyurethanes. Our project on cell adhesion and cytokine release has as its overall goal the evaluation of the effect of biomedical polymers with varying surface properties on the activation and cytokine production of adherent monocytes/macrophages.

 

 

Donald Feke

Associate Faculty

Department of Chemical Engineering

Our research focuses primarily on the physical behavior and processing characteristics of fine particle systems and colloidal suspensions. We are involved in the development of strategies that exploit or control the colloidal and interfacial chemistry of the system to achieve improved processing behavior and ultimately the enhanced performance of the final materials. Specifically, we are involved in the development of colloidal engineering strategies for processing of oxide solids and in fundamental studies of dispersive mixing phenomena for filled polymer composites. Stability and the development of morphology in coatings dispersions are also being studied. In addition, wetting and spreading of liquids on fine-particles is an ongoing research interest, and novel experimental approaches to measure these effects are being developed. Recently, we have begun investigation into simulating and modeling the hydrodynamic, chemical and mechanical effects that occur in polishing processes within the microelectronics fabrication industries with the intent of pointing out process improvements. Finally, we have developed several methods that use resonant acoustic fields to perform sharp fine-particle separations with applications in chemical and biochemical processing.

 

Hossein Ghassemi

Adjunct Assistant Professor

Ph.D., Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, OH

 

J. Adin Mann

Associate Faculty

Department of Chemical Engineering

Light scattering spectroscopy used to measure Visco-elastic response of monolayers has been coupled to BAM. This allows an entirely new set of experiments wherein, for the first time, measurements of the line tension of monolayer domains are possible. Applications are to polymer systems. The theory has been developed in depth. The fundamentals of adhesion are being studied using both a Digital Instruments AFM and an Image Force Microscope built at Sandia National Laboratories by J. Houston. Self-assembly and Langmuir-Blodgett techniques are being used to provide polymer acid-base surfaces. New work on cell membranes was started during the year. The light scattering spectra have been studied for perfect-wetting, binary-mixtures wherein one phase shrinks to a nanometer thick film with temperature. This provides another method of determining the Hamaker coefficient that is fundamental to adhesion. We have started a new project to scale up LB technology for depositing organized polymer films on very large, high definition, active liquid-crystal displays. “Classical” methods of spectroscopy and x-ray, electron diffraction and ellipsometric spectroscopy are used to characterize the films. In addition a second harmonic microscope is being assembled that will be used in combination with Brewster angle microscopy and surface light scattering spectroscopy to characterize Langmuir and Langmuir Blodgett multilayers of polymer systems.

 

 

John Protasiewicz

Associate Faculty

Department of Chemical Engineering

Work is aimed at understanding the fundamental details of transition-metal catalyzed atom and group transfer reactions and to use this knowledge for the development of new catalytic reactions and for the construction of novel materials. The approach involves the rational design of new reagents and ligands for achieving these goals. The group's research cuts through the traditional boundaries of Organic, Inorganic, Organometallic and Main Group Chemistry. Please see the group web site for details on the some specific areas listed below and new entry on Cases's NanoBook.

  1. Novel Materials for Molecular Electronics and Nanotechnology
  2. Mechanistic & Catalytic Reactions
  3. New Ligands for Catalysis based on meta-Terphenyls
  4. Oxo- and Nitrene-Transfer Reactions of Organoiodine(III) Complexes

 

Syed Qutubuddin

Associate Faculty

Department of Chemical Engineering

A colloidal approach has been developed to prepare homogeneous polymer nanocomposites. Work is in progress on the rheology of water-based coatings, structure/property relationships in polymerizable surfactant systems, reactions in microemulsions to obtain nanoparticles, and high performance clay/polymer nanocomposites. Model microemulsion systems which exhibit unique features (e.g. thermodynamic stability and ultralow interfacial tension) were developed. The phase behavior and solubilization in microemulsions have been modeled. Microemulsions are characterized using dynamic and electrophoretic light scattering, electrochemical and other techniques. Microemulsions are attractive as novel media for polymerization and electrochemistry. Microporous polymeric solids as well as uniform spherical nanoparticles are prepared by polymerization of hydrophilic or hydrophobic monomers solubilized in microemulsions. Hydrophilic-hydrophobic copolymers and porous composites are obtained from microemulsions. A novel separation technology using microemulsions as liquid membranes has been developed for extraction of organics, metal ions and proteins.

 

Scott Rickert

Adjunct Faculty

Ph.D., President, NanoFilm Corporation

 

Alan Riga

Adjunct Faculty

Ph.D., Professor of Chemistry, Cleveland State University

 

Charles Rosenblatt

Associate Faculty

Department of Physics

During the past year we have continued our work on nanoscopic patterning of polymer-coated substrates using at atomic force microscope. By scribing tiny patterns into the polymer and depositing a liquid crystal on top, we can compel the nematic director to adopt a well-defined profile that varies on very short length scales. Pixels as small as a few tens of nanometers are possible, with each pixel having a unique easy axis. Work in this area involves studies of phase transitions, wetting phenomena, and development of optical devices, including a new step-wise Fréedericksz transition for which one can use simpler addressing schemes in LCDs. A new thrust was started this year in the area of lamellar liquid crystals. In collaboration with chemist Carsten Tschierske (Halle, Germany), we have been examining lamellar-isotropic, lamellar-nematic, and lamellar-smectic phases. The molecules possess a typical mesogenic chain, but also possesses a semiperfluroinated side chain that causes the mesogenic units to segregate into lamellae. In consequence there exist quasi-two-dimensional analogs to the three dimensional liquid crystalline phases. Initial results indicate that the twist elasticity is more than an order of magnitude smaller than for a 3D nematic due to the large interlamellar separation.

 

Kenneth Singer

Associate Faculty

Department of Physics

Our research focuses on optoelectronic and electronic properties of organic materials. Current projects focus in the areas of organic semiconducting materials and nonlinear optical materials. We are investigating self-assembled and other photoconducting polymers for photorefractive, photovoltaic and other optoelectronic applications. In particular, we are focusing on enhanced carrier mobility in discotic columnar and smectic liquid crystals arising from the enhanced order compared with amorphous polymer materials, as well as enhance mobility due to cross-linked conjugated networks in polymers. We are also investigating paths to optimizing the second order nonlinear optical response in chiral media. We have characterized candidate molecular species by hyper-Rayleigh scattering, developed a simple quantum model, and are investigating schemes for producing ordered chiral media to exploit these nonlinear optical responses. We are investigating supramolecular chiral nonlinear optics responses. Finally, we are studying nonlinear optical responses in liquid crystals due to surface mediated charge interactions.

 

Nicole F. Steinmetz, Ph.D.

Associate Faculty

Biomedical Engineering | School of Medicine

The Steinmetz Lab's mission is to push to new frontiers in medicine and materials through molecular engineering of biology-inspired nanotechnologies. Our vision is the translation of promising nanotechnologies into clinical and commercial applications. Nanoscale engineering is revolutionizing the way we prevent, detect, and treat diseases. Viruses are playing a special role in these developments because they can function as prefabricated nanoparticles naturally evolved to deliver cargos to cells and tissues. My laboratory has developed a library of plant virus-based nanoparticles; through structure-function studies we are beginning to understand how to taylor these materials appropriately for applications in medicine and biotechnology. Research is organized into three interconnected research thrusts:

  • Drug delivery and immunotherapies
  • Molecular imaging for diagnosis and prognosis 
  • Synthetic virology approaches toward novel materials

 

Philip Taylor

Associate Faculty

Department of Physics

One recent focus of research has been the nature of the glass transition in polymeric materials. We study the glass transition in syndiotactic PMMA through atomistic molecular dynamics simulations. The mean squared deviations of atoms, monomers, and molecules from their initial positions are analyzed by means of a technique that separates the effects of diffusive motion from the underlying vibrational motion. The diffusive motion shows a power-law variation with time, with an exponent that varies continuously from 0.5 below the glass transition temperature, Tg, to 1 at high temperatures. The self part of the van Hove correlation functions for both hydrogen atoms and monomers shows structural arrest at the lowest temperature studied. A second peak in the atomic van Hove correlation can be attributed to rotation of the CH3 group. The diffusion of solvents into polymers often causes swelling, and may lead the polymer to pass from the glassy to the rubbery state. However, this process is extremely slow, and has seemed to be inaccessible to simulation using molecular-dynamics techniques. We explore the technique of adjusting the partial charges on the solvent material in order to control the speed of the diffusion process. By completely removing the partial charges on the methano we are able to achieve our objective of studying the diffusion of this modified methanol into poly(methyl methacrylate) in a reasonable computational time. We find penetration of methanol into PMMA to be accompanied by swelling, an increase in radius of gyration of the PMMA molecules of about 7 percent, and an increase in mean squared displacement of the constituent atoms of the PMMA indicative of plasticization. In other work we have explored the interaction between the surface of an amorphous polymer and a nematic liquid crystal. This research involved both molecular modeling and analytical analysis of the classical equations of motion of the polymer and liquid crystal.

 

Horst von Recum

Associate Faculty

Department of Biomedical Engineering

The research in this laboratory focuses on novel platforms for the delivery of molecules and cells. In the molecular delivery projects examination is being made of novel degradable polymer platforms for delivery of therapeutic agents for HIV therapies, wound dressings, ocular disease and localized chemotherapy. Investigations also involve the use of novel stimuli-responsive polymers for use in gene, and drug delivery. These polymers can allow binding and loading under one condition, and release or expression under another condition.

The cellular delivery projects are examined using directed differentiation to produce tissue engineered constructs from stem cell sources. Stem cells show great promise as a therapeutic tool due to there unlimited replication potential and their plasticity, or capacity to become many different cell types. Better control of differentiation and selection, will allow for rapid expansion of high purity differentiated cells suitable for tissue engineering, toxicology and pharmacology, as well as cellular modeling, without the need for isolating cells from primary sources.

 

Christoph Weder

Adjunct Faculty

Dr. sc. nat., Executive Director, Polymer Chemistry and Materials, Adolphe Merkle Institute, University of Fribourg Switzerland