Below is a list of faculty advisers and the title of the project they will be offering during 2017. Click on the faculty to see more information about the project.
Dr. Jeff Anker (Making magnetically controlled “nanopancakes” using mechanical forces )
Title: Making magnetically controlled “nanopancakes” using mechanical forces
The Anker group recently demonstrated that the shape of gold and silver nanoparticles can be altered using the surprisingly simple process of mechanically pressing them into pancakes h a glass rolling pin. Unlike continuous metal films, these gold and silver nanoparticles have a shape and orientation-dependent color in scattered light (sliver nanospheres are blue, and turn red as they flatten, while gold nanospheres are green and turn red as they flatten). We have generated similar pancakes using malleable polystyrene microspheres, and have also been able to embed smaller magnetic nanoparticles into the polystyrene pancakes to allow us to control their position and orientation. The goal of the REU project is to make magnetic gold and silver nanoparticles by either embedding smaller magnetic nanoparticles into the gold/silver, or growing nickel or iron on the surface of the particles. We will then test these magnetic nanoparticles as local probes of viscosity. Long term applications range from development of catalytic nanoparticles to studying intracellular transport.
The goal of the REU project will be to develop magnetic gold and silver nanopancakes. The REU students will be 1) responsible for depositing gold and silver nanoparticles onto glass slides and deforming them into pancakes, 2) analyzing the optical properties of the pancakes using dark field spectroscopy and electron microscopy, 3) embedding magnetic nanoparticles into the pancakes and analyzing the rotation rate of the nanopancakes in viscous water/glycerol solutions in alternating magnetic fields using dark field microscopy videos. The REU student will participate in REU: Surfaces and Interfaces activities, as well as Anker Research Group activities. The REU student will collect, analyze, and regularly present data in a highly active research environment. Finally, the REU student will receive high-quality mentoring from a PhD student and Dr. Anker.
Dr. Raj Bordia (Electrode Microstructure Design for High Capacity Li-Ion Batteries)
Title: Electrode Microstructure Design for High Capacity Li-Ion Batteries
Project Description: Rechargeable Li-ion batteries are widely used in portable electronic devices and in a limited number of automobiles. In order to further increase their acceptance in automobiles and other transportation systems and to increase their performance in portable electronics, several key properties need to be improved. In our lab, we are working on microstructural design of electrodes to enhance the capacity (usable service before charging), and the rate of charging. These two depend on the accessibility of electrode for the electrochemical activities and the diffusion rate of ions or electrons through the electrodes. Commercial lithium ion batteries are manufactured with the combination of powder-based thin laminated electrodes, metal foil as a current collector, separator and infused with liquid electrolytes. In the tape casting technique currently used to fabricate the thin electrodes, particles are randomly packed leading to a highly tortuous path for both the diffusion of ions and electrons. Therefore, only ~50% by volume of the electrode material actively contributes to the electrochemical activity. In this project, we are working on developing engineered hierarchical porous structures with reduced resistance for electron and ion transport. Using meso-scale simulations, we are designing the desirable microstructures and then making them using freeze cast tapes and unidirectional freeze casting of bulk samples. The electrochemical performance of these electrodes is being investigated. A parallel effort is focused on designing the chemical composition of the electrodes to increase the electronic conductivity.
The REU student will work on investigating the effect of processing variable, during freeze casting and subsequent sintering, on the microstructure and the resultant electrochemical properties for one specific electrode. Specific tasks will include: (1) effect of slurry composition and freeze casting parameters (e.g. freezing rate) on the microstructure (including, total porosity, pore size, pore orientation and their distribution); (2) effect of sintering time and temperature on the microstructure; (3) evaluating the electrochemical performance (capacity as a function of charging rate) for the electrodes with engineered microstructure; and (4) working with our collaborators who are simulating the electrochemical properties of these electrodes. The REU student will participate in REU: Surfaces and Interfaces activities, as well as Bordia Research Group activities. The REU student will collect, analyze, and regularly present data in an active research environment. The REU student will work closely with a PhD student, Mr. Milad Azami leading this project. Finally, the REU student will be mentored by all the members of the Bordia research group and by Prof. Bordia
Dr. Kyle Brinkman (Structure Property Relations in Ceramic Composites for Energy Conversion and Storage)
Title: Structure Property Relations in Ceramic Composites for Energy Conversion and Storage
Project Description: Mixed ionic-electronic conductors are widely used in devices for energy conversion and storage. Grain boundaries in these materials have nanoscale spatial dimensions, which can generate substantial resistance to ionic transport due to dopant segregation. Lower resistance to ionic transport may improve the performance of many electrochemical devices (batteries, fuel cells). In model ceramic systems consisting of an ionic conductive phase and an electronic conductive phase we recently reported the concept of targeted phase formation that serves to enhance the grain boundary ionic conductivity. The formation of an emergent phase successfully avoided segregation of the Gd dopant and depletion of oxygen vacancies at the Ce0.8Gd0.2O2-δ-Ce0.8Gd0.2O2-δ grain boundary. This resulted in superior grain boundary ionic conductivity as demonstrated by the enhanced oxygen permeation flux. Current work is focused on the evaluation of surface exchange properties of these materials systems for membrane separations and cathodes for solid oxide fuel cells.
The REU student will work towards understanding the link between composition, processing, microstructure and performance of these materials. The goal of the REU project will be to understand the combined effects of composition and processing induced microstructural modifications to the electrical properties of the material. The REU students will be 1) responsible for fabricating electrolyte materials from solid state and chemical solution processing routes 2) measure the crystal structure of the primary and any associated secondary phases and 3) examine the local chemical composition and microstructure with Scanning Electron Microscopy techniques, 4) measure surface exchange properties using electrical conductivity relaxation techniques (ECR) and 5) measure the temperature dependent conductivity of the samples using AC impedance spectroscopy. The REU student will participate in REU: Surfaces and Interfaces activities, as well as Brinkman Research Group activities. The REU student will collect, analyze, and regularly present data in a highly active research environment. Finally, the REU student will receive high-quality mentoring from a Postdoctoral researcher and Dr. Brinkman.
Dr. Dean (Response of dental pulp cells to microenvironment)
Title: Response of dental pulp cells to microenvironment
Project Description: Our goal is to understand what microenvironmental factors are necessary to efficiently steer the differentiation of dental pulp cells. Dental pulp, similar to bone marrow, contains a type of stem cells that help to maintain and repair the injured teeth. The cells are greatly influenced by their microenvironment and small changes in extracellular matrix composition and architecture can affect the lineage to which the stem cells differentiate. In past studies, we have used spider silk and have shown that the cells will preferentially align along the silk fiber. Our current study will focus on using biomimetic fibrous scaffolds to push dental pulp cells to odontoblastic and neural cell lineages. In addition, the effect external stimuli such as mechanical force and radiation environment will also be examined.
Dr. Konstantin (Kostya) Kornev (Sensing small changes of environment using torsional properties of natural fibers)
Title: Sensing small changes of environment using torsional properties of natural fibers
Project Description: Often, material scientists and engineers look towards nature for solutions to current technological challenges. Insect fibers such as butterfly proboscis or antennae are the excellent examples of complex systems inspiring engineers. A proboscis is a complex, flexible, elastic, partially porous, tubular structure used by butterflies to drink nectar from flowers. Antennae are hollow fibers with a complex shape and internal organization of materials. These fibers are equipped with sensors which we are currently study. We develop a method that allows us to study mechanical response of a proboscis or antenna of a live butterfly to externally applied torque. Contrary to conventional methods for torsional analysis of fibers, we probe magnetic response of a tiny probe attached to the fiber tip. Hence the magnetic probe can be actuated and tracked from a distance. This makes it extremely attractive for studies of live bio-fibers. The project aims to probe the torsional properties of proboscises and antennae of live butterflies at different environmental conditions with a goal to elucidate the materials reaction on minute changes in humidity and temperature.
Dr. Olga Kuksenok (Improving Thermal Stability of Enzymes via Conjugation with Copolymer: Computer Simulation Study)
Title: Improving Thermal Stability of Enzymes via Conjugation with Copolymer: Computer Simulation Study
Project Description: Enzymes are environmentally friendly and safe catalysts that accelerate a range of chemical reactions by many orders of magnitude, thereby improving thermal stability of enzymes is vital for a variety of applications incorporating them into engineering materials, from the deactivation of toxic materials and biomedical applications to biological fuel cells. Recent simulations in Kuksenok’s group integrated with the concurrent experimental studies of our collaborators demonstrate that by conjugating enzymes with copolymers one can dramatically improve their thermal stability well beyond that of native enzymes. We use molecular dynamics simulations to study the thermal stability of the lysozyme-polymer conjugates (LPCs) with respect to that of native lysozyme. To design the LPC, we conjugated the lysine residues of lysozyme with the same copolymer that was used in the experimental study. Importantly, we show that the choice of the specific copolymer architecture is critically important for optimizing the thermal stability of the lysosome.
The REU student will focus on computational modeling of the effect of the given copolymer architecture on the thermal stability of the enzymes complexes. Specifically, the goal of the REU project will be to understand the effect of volume fraction of this copolymer on the thermal stability of the lysozyme-polymer conjugates. The REU student will learn the basics of molecular simulations and with run computer simulations using GROMACS software. The REU student will learn how to run computer simulations on the Palmetto cluster, which is Clemson University’s high-performance computing resource and is ranked #4 among academic research clusters in the US. Some prior programming experience is beneficial; the REU student will learn to work in Linux environment. The REU student will analyze the data obtained from the simulation studies and will present the results during the group meetings. By the end of the program the REU student will write a report summarizing his/her findings. The REU student will participate in the Kuksenok Research Group activities
Dr. Igor Luzinov (Fabrication of reduced graphene oxide nanoscale films)
Title: Fabrication of reduced graphene oxide nanoscale films
Project Description: The major goal of the proposed research is to develop methods of formation of reduced graphene oxide (rGO) films for employment in conductive polymer composites. The fabrication method of the rGO nanoscale film relies upon enveloping individual GO sheets in a nanometer-thick polymer layer, allowing for the formation of a nearly perfect GO monolayers by dip-coating, The following scientific questions will be addressed in course of the study: (a) what dip-coating conditions will produce a uniform and densely packed monolayer of GO? (b) what are the necessary conditions for reduction of GO structure to obtain highly conductive rGO layers?
Dr. Thompson Mefford (Polymerization of stabilizing polymer brushes on the surface of metal oxide nanoparticles)
Title: Polymerization of stabilizing polymer brushes on the surface of metal oxide nanoparticles.
Project Description: This project will explore the synthesis of multifunctional polymer brushes for ligand exchange on the surface of inorganic particles. The majority of nanoparticles are produced with a “sacrificial” ligand which is then exchanged with one with properties better suited for the given biomedical, catalytic, or energy application. This exchange is critical for the success of these applications as the resulting surface chemistry will be a major factor in the resulting colloidal stability, reactivity, and dielectric properties of the particle/ligand system. Central to the success of changing the surface chemistry is the functionality of the replacing polymer brush. We have recently used methods to synthesize radiolabeled metal and metal oxide nanoparticles with radiolabeled capping ligands and use liquid scintillation counting (LSC) to measure how much radiolabeled original ligand has been displaced on the surface of the nanoparticles during exchange with a hydrophilic ligand.
For this project, students will synthesize new multifunctional polymers via RAFT polymerization and then measure the interaction of these materials with the surfaces of nanoparticles. The resulting polymer-particle composites will be characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM). In addition, unlabeled particles will be synthesized and modified in order to compare LSC to other methods commonly used to characterize modified particles, including TEM, DLS, and TGA.
Students involved in this project will gain first-hand experience in the chemical synthesis of nanomaterials, measurement of the colloidal properties of these materials, and unique polymer synthesis techniques. Specifically, the student will learn synthetic techniques for the formation of metal oxide nanoparticles through controlled LaMer reaction kinetics. The student will then characterize these materials via TEM, Zeta potential, DLS, and X-ray diffraction (XRD). Finally, the student will utilize our recently developed techniques to measure the change in surface chemistry of the engineered nanoparticles which can be applied to many different fields, providing a research experience that will support future endeavors by the student.
Dr. Lindsay Shuller- Nickles (Developing More Sustainable Pesticides by Understanding the Chiral Switch)
Title: Developing More Sustainable Pesticides by Understanding the Chiral Switch
Project Description: Pesticide use in the US and worldwide is ever increasing with demands to produce enough food to feed most of the world and to protect vulnerable populations from severe diseases such as malaria. However, controlling the effects of pesticides for non-target organisms, including humans, is challenging, and a substantial decrease in the amount of pesticides applied each year would further sustainability efforts. One such effort is to manufacture and market only the most effective enantiomer of chiral pesticides. If the molecules are alike in every way but they are mirror images of each other, then they are termed chiral, and the mirror images, known as enantiomers. In this class of pesticides, one of the enantiomers acts as a pesticide and the other is benign. Thus, if the effective enantiomer can be isolated, less total chemical needs to be applied. The challenge comes in that some enantiomers, when applied to the environment, undergo a chiral switch such that the single effective enantiomer switches back to the benign enantiomer resulting in the need for additional application of the pesticide.
The objective of this research is to characterize the role of mineral surfaces on the chiral switch process. Specifically, quantum-mechanical and molecular mechanics calculations will be performed to characterize the interactions between chiral pesticide molecules (e.g., malathion and metalaxyl) and mineral surfaces (e.g., calcite (104) and (214) surfaces). Sorption energies and geometries, as well as the dynamics of the chiral switch, will be evaluated for both chiral (calcite (214)) and achiral (calcite (104)) mineral surfaces.
Dr. Ken Webb (Injectable hydrogels with magnetically aligned structures for nerve regeneration)
Title: Injectable hydrogels with magnetically aligned structures for nerve regeneration
Project Description: Due to the limited regenerative capacity of the adult central nervous system (CNS), spinal cord injury (SCI) leads to permanent loss of motor and sensory function. Achieving meaningful improvements in functional recovery will require the development of therapies that can stimulate severed axons to regenerate and reconnect with their targets. Unfortunately, there are a wide range of both developmentally-related and injury-induced barriers that must be overcome in order for this to be accomplished. One critical barrier is the formation of a cystic cavity at the injury site and corresponding destruction of highly organized structures of supporting glia and extracellular matrix that originally directed axonal growth during development. Many researchers are investigating implantable scaffolds with structural organization such as aligned fibers and channels that can restore this topographic guidance to injured axons. An important limitation of this approach is that most of these materials require highly invasive implantation procedures when most human injuries are incomplete and of uncertain initial prognosis. On the other hand, a variety of injectable hydrogel materials have been developed that can be delivered in a minimally invasive manner with much lower risk of causing further damage. However, these polymer networks are amorphous and lack structural features suitable for topographic guidance.
We are working on a new technology to overcome these challenges. Specifically, our goal is to electrospin degradable polymeric nanofibers containing magnetic nanoparticles, shred these fabrics into micrometer scale segments that can be incorporated within an injectable hydrogel, and then subsequently re-assemble these segments into aligned fibers immediately following implantation using an external magnet. We seek an REU student to assist with the investigation of segmentation procedures and characterization of the size, variability, and bioactivity of the resulting segments.