College of Engineering

William Kraft

College of Arts & Sciences Physics

Faculty Mentor: Dr. Steven May Materials Science & Engineering

Yizhou Yang Graduate Student

of Ca2Fe2O5 Thin Films

Atomic substitutions are one of the central strategies for tuning material properties. Oxyfluorides, in which some oxygen anions are replaced by fluorine anions, can exhibit different optical, magnetic, and structural properties than those of oxides. However, to fully utilize anion substitutions in these materials, fundamental studies are needed to understand how to control the amount of fluorine that substitutes for oxygen. In this work, Ca2Fe2O5 thin films with the brownmillerite crystal structure were grown on different substrates via molecular beam epitaxy and fluorinated using a vapor transport process which employs argon gas and fluoropolymer pellets as the fluorine source. Depending on the substrate on which the films were deposited, those vacancies were oriented either parallel or perpendicular to the substrate. By fluorinating an oxygen-deficient brownmillerite with a controlled vacancy ordering, one might be able to insert different amounts of fluorine depending on the vacancy ordering direction of the film. X-ray photoelectron spectroscopy was used to determine the fluorine content of each of the films, revealing the relationship between the orientation of the vacancies and the fluorine concentration.

College of Engineering

Engy Khoshit

College of Engineering

Materials Science and Engineering

Faculty Mentor: Dr. Caroline Schauer

Materials Science & Engineering

Dr. Reva Street

Co-Mentor

Heavy Metal Filtration via Electrospun Natural Polymers

Lack of safe drinking water has continued to be one of the biggest humanitarian issues over the past few decades as the CDC estimates that almost a billion people do not have access to a safe water source. To prevent further depletion of the earth’s resources, natural polymers such as keratin, chitosan, pectin, gelatin, and alginate can be used for filtering heavy metal contaminants such as hexavalent chromium, arsenic, and lead. Creating nanofiber meshes via electrospinning would allow for adequate filtration testing as well as allow for larger scale fiber collection via touchspinning or other apparatuses. Since keratin has not yet been successfully electrospun on its own, utilizing the four other natural polymers would allow fibers to be electrospun in different ratios to analyze the differences on a nanoscale and expand it to a larger, more viable system.