Faculty advisors are active in the study of the structure, reactivity and thermodynamics of materials in addition to the characterization of their electronic and optical properties. Research groups consist of faculty and graduate students from the Chemistry and Physics Departments who guide undergraduate participants in the program.

Spectroscopic and Thermodynamic Studies of Oil Dispersants at the Oil/Water Interface
Geraldine Richmond, REU Program Director
Oil dispersants have a history of being used to break-up oil spills but as we have witnessed in the recent Gulf oil spill, little is known about their toxicity and their effectiveness in sea water.  Our interest is to contribute to the understanding on a molecular level of how relevant dispersants behave at an oil/water interface under conditions where the composition of the aqueous phase is altered in acidity and salt concentration.  In this project we will use vibrational sum frequency spectroscopy (VSFS) and interfacial surface tension to examine two families of surfactants at the CCl4/H2O interface; sodium dioctylsulfosuccinate and sorbitan monooleate.

The REU student will conduct two kinds of experiments:  (1) VSF measurements of the vibrational spectroscopy of the dispersant at an organic/water interface, and (2) interfacial tension measurements using the pendant drop method.  The spectroscopy experiments will be conducted initially with a graduate student until he/she is familiar with the laser system and can work more independently. The project will be a valuable experience for the REU participant in combining their chemistry and physics knowledge while learning about surface science, molecular modeling, spectral analysis, laser spectroscopy, and nonlinear optics.

The "Cheerios" effect: Surface Tension Mediated Interactions
Eric Corwin, Physics
Objects at the surface of an air-water interface interact with one another through deformation of the interface. The nature of this interaction is determined by the shape, buoyancy, and interfacial contact angle of the objects and is readily seen in the clumping together of Cheerios in a bowl of milk, from which this phenomenon draws its colloquial name. Using chaotic Faraday waves on a fluid surface we have developed an experimental protocol to create a pseudo-thermal bath for such particles. An REU student in our lab would use shape and density tuned particles to explore self-assembly into complex structures. This will involve the design and fabrication, using a 3D printer, of new particle shapes, and the computer aided real-time tracking and analysis of the movements of the particles under the influence of the specified inter-particle potentials.

Ionic Junctions of Solar Energy Conversion
Mark Lonergan, Chemistry
Traditional photovoltaics rely on an asymmetry in electronic structure or electronic carrier type for selective carrier collection and the  conversion of solar radiation into electricity.  We are exploring the   use of an asymmetry in ionic content in mixed ionic/electronic conducting polymers as a means for generating a photovoltaic effect.   The asymmetry in ionic content also leads to redox chemistry making   possible new hybrid battery/photovoltaic concepts for both energy conversion and storage.   
Students working on this project will be involved in the synthesis of ionically functionalized conjugated polymers and their detailed electrochemical characterization.  They will also be involved in the fabrication of multilayer polymer structures and their structural and electrochemical characterization.   A primary goal will be the fundamental understanding of mixed ionic/electronic conducting interfaces that use sunlight to directly drive redox disproportionation as a means of energy storage.

Coarse-graining and Multiscale Modeling Applications to the Study of Polymer Solar Cells
Marina Guenza, Chemistry
Polymer solar cells are an inexpensive alternative to silicon solar cells and have a significant industrial potential because of the light weight, mechanical flexibility, and potential for low-cost production. Current challenges in polymer solar cell research include improving performance at elevated temperatures (thermal stability) and increasing power-conversion efficiency with respect to inorganic solar cells.  
 
A key step to improve thermal stability and efficiency of polymer solar cells is to develop a deeper understanding of the microscopic mechanisms that lead polymeric materials used in solar cells to perform the way they do. For example, it has been demonstrated that improvements in power-conversion efficiency and thermal stability can be accomplished by applying post-production annealing at elevated temperatures for 30 minutes (1). The improved performance is attributed to the formation of crystalline, ordered, regions in the semiconductor polymer formed during annealing, while avoiding phase separation of the two components. It is evident that the solar cell performance is highly sensitive to the thermal and mechanical history of the polymer systems involved.

 To study morphology and thermal history of semiconductor polymers used in solar cells it is useful to perform computer simulation studies of these model systems. Data from simulations will stimulate new theoretical statistical mechanics models. Because the challenge in simulating polymeric systems for solar cells is to be able to cover the large range of length scales that are relevant for the photoconversion process, it is important to develop computational methods that allow one to do so. In Guenza’s group we have proposed novel coarse-graining methods and multiscale modeling procedures for polymeric systems that efficiently extend the range of time- and length-scales that can be investigated in molecular dynamic simulations (2-5).

The current REU project aims at extending these methods to specific polymeric systems useful for photovoltaic solar cells. The ultimate goal is to understand how to control the morphology of the system on the nanoscale as a function of the polymeric structures, mixture composition, and thermodynamic conditions. The REU student involved in this project will work closely with Chemistry and Physics graduate students to develop new theoretical approaches for coarse-graining and multiscale modeling starting from non-equilibrium statistical mechanics and liquid state theory. The student will also assist with computer simulations of polymeric systems for photovoltaic solar cells.

Interdiffusion and Nucleation at the Interface of Reacting Solids
Dave Johnson, Chemistry
By using elementally modulated reactants in which composition can be controlled on an ngstrom length scale, we have been able to use slow solid state diffusion rates as a synthetic advantage. Controlled crystallization of elementally modulated reactants results in the rational synthesis of targeted compounds. There are several projects for REU students. These include preparing new thermoelectric materials and measuring their properties, preparing new extended cluster compounds, and preparing crystalline superlattices containing interwoven layers of different compounds. All of these projects involve preparing thermodynamically unstable compounds which cannot be prepared using conventional synthesis techniques. Although the compounds are thermodynamically unstable, they are kinetically stable. The structure of the superlattice compounds is controlled by the structure of the initial modulated elemental reactant. The rational synthesis of superlattice compounds permits the tailoring of physical properties as a function of compositional layer thicknesses and native properties of the parent compounds. The structure of the resulting products is characterized using transmission electron microscopy and x-ray diffraction. The student will measure the properties of the compounds he/she prepares, using electrical conductivity, Seebeck coefficients, Hall measurements and thermal conductivity measurements to correlate properties with structure and composition. We have had an excellent track record (in publications alone) in involving both undergraduate physics and chemistry majors in projects like these and we anticipate that this will continue in the future.

Greener Synthesis of Functionalized Inorganic Nanoparticles
Jim Hutchison, Chemistry
During the synthesis of functionalized nanoparticles, hundreds to thousands of atoms assemble into the desired structure in, typically, a rapid series of reaction steps.  Little is known about the mechanisms of these reactions and, as a consequence, syntheses are inefficient and often involve the use of highly reactive hazardous reagents. As nanotechnology moves away from demonstration to application, greener approaches to producing these materials will be essential to protecting the environment and providing benefit to society.  Given the projected broad application of nanotechnology, greening the production of nanoparticles is an important challenge for green chemistry.

New Catalyst for Environmentally Designed Ammonia
David Tyler, Chemistry
The Haber-Bosch process for the production of ammonia from N2 and H2 was arguably the most important invention of the twentieth century.  Approximately 108 tons of industrial ammonia are produced annually, and the fertilizer synthesized from this ammonia is responsible for feeding over 40% of the world’s population.  (This amount is predicted to rise to 60% by 2050.)  Temperatures of 350-550 °C and pressures in the range of 150-350 atm are required for industrial nitrogen fixation.  Such drastic reaction conditions, combined with the energy required to produce H2, account for ~1-2% of the total annual global energy consumption and for the output of greater than 3.3 ´ 108 M tons/yr of CO2 (7.3% of the worldwide total).  Due to the high energy input and high CO2 output, finding a more environmentally benign process to fix N2 is one of the grand challenges in green chemistry.  We recently reported the first example of the room temperature, atmospheric pressure reduction of N2 to NH3 using H2 as the reductant.  The reaction uses water-soluble Fe-phosphine complexes of the type Fe(P2)2Cl2 to assist in the reaction, where P2 represents a water-soluble bidentate phosphine ligand.  Our goals are to understand the mechanism of the reaction and to make the process catalytic. 

Coherent Matter Wave Manipulation using Diffractive Electron Optics
Ben McMorran, Physics
The McMorran Lab is interested in developing and applying new methods in electron microscopy, holography, and nanofabrication to gain fundamental insights into the properties and quantum behavior of matter. Our lab has pioneered the use of nanofabricated holograms to diffract and coherently sculpt electron matter waves with picoscale feature sizes. We apply this technique inside conventional electron microscopes to prepare electrons in desired quantum states. One highlight of this research is the demonstration of electron vortex beams, composed of freely propagating electrons in quantized orbital states. In addition to performing fundamental investigations of how these unusual free electron states evolve in free space and interact with electromagnetic fields and matter, the group has a particular interest in applying these beams to study magnetic materials and biomaterials.
The REU project will involve nanofabrication (focused ion beam (FIB) milling, e-beam lithography, and thin film deposition), matter wave optics experiments using electron microscopes, and/or software programming, theoretical studies, and computer simulations, all depending upon the student’s interests. The student will work alongside graduate and undergraduate students to learn about electron microscopy and imaging systems, interferometry and holography, and the quantum behavior of matter.

Optical Metrology with Quantum Entangled Light
Michael Raymer, Physics
The past decade has seen advances in techniques for manipulating and measuring physical objects at the quantum level, opening a new avenue for research – Quantum Metrology. This includes quantum imaging, frequency standards, and precision time measurements. New quantum techniques offer promise for increased sensitivity and resolution. This REU project focuses on using intrinsically quantum states of light for ultrafast spectroscopy and imaging of macromolecules and other systems including biological and photosynthetic ones relating to light harvesting. Two-photon entangled states have the potential to provide simultaneous time and frequency information beyond the usual uncertainty limits, to provide enhanced microscopic spatial resolution without the deleterious effects of photo-bleaching, and to excite molecules or semiconductors along certain pathways with enhanced control. The REU student may work with diode or titanium-sapphire lasers, single-photon detectors, optical fibers, interferometers, nonlinear optics, and computer interfacing.

Multiscale Thin Metal Films for Enhanced Sensing and Light Harvesting Applications – Energy Transfer and Charge Transport Studies
Miriam Deutsch, Physics
Research interests in the Deutsch Group involve understanding the fundamental optical and electronic properties of metals exhibiting structure on a hierarchy of length scales, ranging from several nanometers to optical (micrometer) scales. Metal films with multi-scale structural roughness have been gaining newfound interest in recent years with applications that include substrates with plasmon-mediated nonlinear optical response for sensing applications and increasing solar cell efficiencies using highly scattering thin metal films. Research efforts are currently addressing energy transfer (optical excitations) and charge transport through chemically deposited thin silver films. Better understanding of energetic processes in these materials will allow optimization of their use as targeted sensors for biological or chemical contaminants, as well as their implementation in efficient light harvesting devices.

Measuring the two-dimensional viscosity of lipid membranes
Raghuveer Parthasarathy, Physics
Our group explores the physical properties of biological membranes. Membranes are amazing materials -- flexible, two-dimensional fluids. Membrane fluidity allows lipid and protein molecules to move and interact with one another, performing chemical reactions and constructing spatial relationships. Despite this, the viscosity of lipid membranes remains poorly characterized. Our lab has been developing new techniques to measure membrane viscosity and is using these to quantify the fluid dynamics of various sorts of membranes. An REU student in our lab would work on performing these experiments, using microscopy and computational image analysis methods to characterize an important class of biomaterials.

Electron-Accepting Organic Semiconductors
Michael Haley, Chemistry
Polycyclic hydrocarbons that possess extended pi-conjugation are of tremendous interest because of their potential use in optical and electronic device applications. While a majority of studies have focused on acenes and their derivatives, these systems are susceptible to oxidative and photolytic degradation; thus, there is a pressing need for alternative, acene-like topologies. Current research in the lab is focused on molecules based on or inspired by the indenofluorene (IF) skeleton. Over the last few years, we have adapted and/or developed general methods for the assembly of a variety of fully conjugated IF derivatives and initiated exploration of their materials properties. We have shown that IFs can be prepared gram quantities in good overall yields and in excellent purity. Indenofluorenes have the potential to act as rigid, planar, electron-accepting cores for the formation of advanced materials with novel electronic properties. We are exploiting the materials potential of IFs via a combined experimental and theoretical approach, with an emphasis towards use of indenofluorenes as organic semiconductors in devices. Importantly, we demonstrated recently that single crystals of a perfluorophenyl-substituted IF could serve as an active layer in an organic field-effect transistor that exhibits ambipolar behavior.

An REU student would help construct and study additional indenofluorene scaffolds, thus further refining their design for optimal semiconductor properties. A small set of new targets would first be identified and then prepared. Given that our syntheses are modular (think molecular level Legos or Tinkertoys), most of the starting materials are readily available; thus, construction of the compounds would be straightforward. The student would characterize the new molecules by traditional techniques (NMR, IR, UV-vis, MS) as well as more elaborate methods (x-ray crystallography, fluorescence including lifetimes, EPR).

Controlling Properties of Graphene Devices through Surface Chemistry
George Nazin Chemistry
Organic semiconductors have received a great deal of attention due to their potential for fabrication of lightweight, large-area, and low-cost solar cells. One important issue for the commercial viability of organic solar cells is the cost-efficient fabrication of transparent, conducting electrodes, which are required for the light to be able to reach the active area of the cell. Currently, the materials available for fabrication of transparent electrodes are either too expensive or have suboptimal conductivities. A promising novel transparent electronic material is graphene which has exceptionally high charge carrier mobility. We are investigating the routes to chemical manipulation of graphene bandstructure, which is important for fabrication of cells with efficient collection of photo-generated charge carriers.
The undergraduate student involved in the project will participate in the studies of graphene device doping via surface chemistry methods. The student will be trained (under the guidance of a graduate student) in the following techniques: optical spectroscopic characterization of graphene, fabrication of graphene devices using e-beam lithography, vacuum-based graphene surface chemical modification, electrical characterization of the graphene devices, and investigations of the device’s internal band-structure profiles using scanning photocurrent and scanning gate microscopies.

Supramolecular Chemistry
Darren Johnson, Chemistry
The Johnson laboratory uses supramolecular chemistry as a tool to approach a variety of problems in organic, inorganic and environmental chemistry.  Research topics include i) developing a supramolecular design strategy for the specific chelation of hazardous metals such as arsenic, lead, and mercury; ii) molecular recognition of anions and biologically relevant small molecules, and iii) developing greener approaches to prepare metal oxide thin films for electronic device applications.  Students can also participate in inorganic nanocluster synthesis within our Center for Green Materials Chemistry (http://uoregon.edu/~grnchem/).
REU students would be introduced to concepts in the field of supramolecular chemistry and they will specifically apply the principles of self-assembly, molecular recognition, organic, and inorganic synthesis to prepare new molecules.  A representative project for an REU student would involve first learning the basics of computer modeling (molecular mechanics and DFT) to design a ligand capable of forming a nanoscale assembly in the presence of a specific toxic metal ion such as As3+ or Hg2+. Ligands designed from this work will selectively chelate the target toxic metal ion, enabling applications in environmental remediation and sensing of a variety of problematic environmental contaminants. The REU student would perform the organic synthesis necessary to prepare the ligand, the inorganic synthesis required to form the complex, and the characterization to prove the assembly composition (NMR spectroscopy, mass spectrometry, X-ray crystallography, etc.).  This project will give the student a working knowledge of supramolecular chemistry, expose him/her to the basics of computer modeling, and provide hands-on organic and inorganic synthesis experience.  

Inorganic Materials Chemistry for Solar Energy Conversion and Storage
Shannon Boettcher, Chemistry
The continued prosperity of our current civilization will require replacing fossil fuels with renewable, sustainable energy sources. Using sunlight, by far the largest power source on the planet, to generate portable, energy-dense fuels via a closed-loop chemical cycle is arguably the most attractive solution. The simplest cycle imaginable would involve the photo-driven splitting of water into molecular oxygen and hydrogen. The Boettcher group synthesizes and studies solid-state inorganic materials that may be useful for facilitating this process. Students working on this project will use solution-phase inorganic chemistry to synthesize oxide-based semiconductors. The relevant physical/structure properties will characterized using a variety of materials analysis techniques (x-ray diffraction, electron microscopy, x-ray photoelectron spectroscopy, etc.) and correlated to photo- and electrocatalytic behavior. 

Influence of nanoparticles on RNA structure and function
Vickie DeRose, Chemistry
As the development of nano-scale materials progresses, it is important to understand how these materials may influence the physical and chemical properties of biological macromolecules such as RNA.  RNA molecules carry a large negative electrostatic potential, attract an atmosphere of cationic counterions, and have nanoscale regions of architecture that may associate strongly with nanoparticles in a materials-dependent manner. The goals of this research are to investigate such associations and their consequences to RNA structure and function. As an initial screen for binding and structure changes, the activity of a ribozyme (catalytic RNA) will be used to monitor influences of nanoparticles on RNA.

Students working on this project will learn to perform kinetic assays for RNA reactivity based on the hammerhead ribozyme, a 65-nucleotide RNA whose activity is very sensitive to structure and cations. REU students will then investigate the influence of different nanoparticles, Ga (13) metal clusters and size- and ligand-shell-controlled Au nanoparticles on the RNA catalyst using the kinetic assay for ribozyme activity. Depending on timeframe, students will either use materials provided by the Johnson and Hutchison laboratories, or synthesize and characterize their own materials. These experiments will provide cross-training in important concepts of kinetics, biopolymer structure, handling and possibly synthesizing nanomaterials, and quantitative analysis of complex molecules.

Quantum Measurements and Quantum Dynamical Systems
Dan Steck, Physics
One of the most intriguing aspects of quantum mechanics remains the measurement process.  An important modern paradigm for quantum measurement is the continuous, indirect measurement of quantum systems–in our case, ultracold rubidium atoms trapped by laser light.  We are working towards realizing and better understanding continuous quantum measurements, with two main long-term goals.  First, we are working towards implementing quantum feedback control of atomic motion, which is inherently challenging due to quantum mechanics itself: to control the state of an atom, we must continuously gain information about it, but to gain the information we must also disturb them.  This is, unfortunately, contrary to our control goals of putting the atom into a desired state.  Second, we are working towards understanding the correspondence between classical and quantum mechanics, which is particularly challenging for systems that are chaotic in the classical limit.  Further, understanding continuous quantum measurements will benefit future technologies in quantum-information processing and quantum-limited, precision metrology.

The REU student in our group will work closely with me and graduate students on any of a variety of projects according to the student's interests, in support of our experiments on continuous measurements of the motion of ultracold atoms, ranging from designing and constructing electronics and laser systems to theoretical simulations.  Possible projects include: developing novel, microcontroller-based hardware for timing and control of cold-atom experiments; developing and characterizing ultrastable diode-laser systems; helping to design and set up optical detection systems to track single, trapped atoms in real time; and computational simulations of optical continuous measurements on single atoms.

Using retinal implants to restore vision to the blind
Richard Taylor, Physics
Technological advances over the past few decades have transformed the concept of bionic eyes from the wild speculations of science fiction into the practicalities of science fact. With over one million people diagnosed with retinal diseases each year, the aim is to restore vision by replacing damaged rods and cones with artificial photoreceptors. Clinical trials are already under way using retinal implants based on camera chip technology. However, there are crucial differences between how the human visual system and the camera “see”. These differences arise because, while the camera uses the Euclidean shapes favoured by engineers, the eye exploits the fractal geometry that is ubiquitous throughout nature. This project investigates the advantages of fractal-based implants. These include an increase in visual acuity by over an order of magnitude, potentially allowing people to read text and facial expressions – essential capabilities for performing every day tasks. Furthermore, unlike current designs, fractal implants will trigger the physiological mechanism used by the human visual system to prevent our stress-levels from soaring. This latter effect holds crucial implications for society: the U.S. spends over $300 billion annually on stress-induced illnesses, and stress is increasingly blamed for precipitating debilitating disorders such as schizophrenia and cancer.

Developing New Chemical Tools for Chemical Biology
Michael Pluth, Chemistry
The Pluth lab uses molecular recognition strategies to design new chemical tool for detecting important biological species. As new biological analytes are discovered, sensitive tools are needed to visualize these species in live cells and tissues. We use a variety of synthetic (organic, inorganic, air-free) and spectroscopic (UV-vis, IR, UV-vis, fluorescence) techniques to prepare, characterize, and test our developed scaffolds. Recently, we have developed a series of visible, fluorescent, and chemiluminescent probes to visualize hydrogen sulfide (H2S) in different environments. We are interested in further sharpening these recently-developed tools and also developing new, selective, detection methods for other important biological analytes. 

REU students would be introduced to commonly-used techniques in the Pluth lab including organic synthesis, compound purification, and photophysical studies. A representative project for an REU student would be preparing a chromophore with a reactive group able to detect a biological analyte such as H2S. After preparation of the scaffold, the photophysical properties, such as extinction coefficient and quantum yield, would be measured. After learning about handling reactive biological species, the selectivity of the developed scaffold would be tested to determine whether the desired selectivity was obtained.  Such a project would provide the students with a working knowledge of contemporary goals in chemical biology, expose him/her to the basics of visible spectroscopies, and provide hands-on organic synthesis experience.