Student(s): Natalie Westwood, Evan Woodward
Project: Development of YSZ-Chitosan Nanoceramic Thin Films for Improved Surface Durability
Advisor(s): Ricardo Castro
Abstract
This research focuses on deriving an eco-friendly nanoceramic-chitosan thin-film coating aimed at enhancing surface hardness and scratch resistance for various applications, such as automotive surfaces, kitchen counters, and even musical instruments. The film includes 1.5 mol% yttria stabilized zirconia (YSZ), which is synthesized via coprecipitation and further refined by milling and sonication into nanoparticles (~10 nm), before being dispersed into a chitosan solution. YSZ is a ceramic in which yttria addition can promote transformation toughening, allowing for high strength and toughness. When added to chitosan in solution, these YSZ nanoparticles can disperse throughout the deposited film and provide added scratch resistance to the chosen applied surface. The main focus has been on automotive surfaces, with painted steel panels being used as substrates to represent various car models. Application methods such as spin coating, spray coating, and dipping were investigated, with dipping leading to the most homogeneous surface and spray coating giving the most consistent data. Micro-hardness and scratch tests on dipped film showed up to a 20 HV increase in hardness and lesser penetration depth when compared with commercial buffed coatings. Scratch testing also showed that YSZ nanoparticles decreased scratch penetration by 20 μm at 4N of force, compared to plain chitosan. Future work includes improving adhesive properties to expand application methods as well as enable the use of the coating for other substrate types, such as wood or glass surfaces.
About Natalie Westwood
Major: Materials Science and Engineering
Natalie Westwood is a third-year Materials Science and Engineering student at Lehigh University. She grew up in Houston, Texas, with two older siblings and two dogs and graduated from Kingwood High School. At Lehigh, Natalie is a member of the Varsity Women’s Soccer Team, where she has strengthened her work ethic, discipline, and organizational skills. She is also involved in the Society of Women in Engineering and the Student Athlete Mentorship Program. Last summer, Natalie worked as a research assistant in Dr. Ricardo Castro’s lab at Lehigh. With her research partner, Evan Woodward, she studied nanoceramic thin films, focusing on sustainable, scratch-resistant protective coatings made from composite films of chitosan, a bio-derived polymer, and yttria-stabilized zirconia nanoparticles. Her research aims to improve scratch resistance and hardness while maintaining sustainability. This summer, Natalie will intern at Los Alamos National Laboratory in the Electrical Engineering Department, studying different adhesive materials and their applications.
About Evan Woodward
Major: Materials Science and Engineering
Evan Woodward is a fourth-year Materials Science and Engineering student at Lehigh University, where he is also pursuing a minor in polymer science. He is from Pottsville, Pennsylvania, where he grew up with a younger brother and graduated from Pottsville Area High School. At Lehigh, Evan is a Rossin Junior Fellow, secretary of the Student Materials Society (SMS), and a member of the student sports broadcasting club. Evan’s research under Dr. Ricardo Castro of the Materials Science and Engineering Department focuses on developing a YSZ-chitosan thin film that can be applied on a variety of surfaces, namely on car exteriors to provide added scratch resistance. Over the past three summers, Evan has been a Mountaintop Fellow on the PlasTech Ventures team, worked at Hexcel Corporation, and at Lycoming Engines. Upon graduation this spring, he will be rejoining Lycoming’s parent company, Textron, in their Leadership Development Program.