The Composto Group is proud to celebrate Dr. Katie Sun on the successful defense of her dissertation, “Effects of Polymer Brush, Nanoparticle, and Solvent Characteristics on Nanoparticle Adsorption.” Her research examined how polymer-brush structure, solution pH, grafting density, molecular weight, and nanoparticle geometry influence nanoparticle adsorption and separation. Using quartz crystal microbalance with dissipation monitoring and microscopy, Katie demonstrated how electrostatic and steric interactions can be tuned to control particle uptake, penetration, and selectivity within weak polyelectrolyte brushes. Her work provides valuable insight into the design of responsive surface coatings for future filtration and nanometer-scale separation technologies.

We thank Katie for her many contributions to the Composto Group and to the broader fields of polymer science, nanomaterials, and surface engineering. We also recognize her co-advisor, Professor Karen Winey, and her committee members, Professor Daeyeon Lee and Professor Robert Riggleman, for their mentorship and guidance throughout her doctoral journey. We are proud to welcome Katie as a Composto Group alumna and are excited to see where she takes her knowledge, creativity, and talents as she begins the next stage of her career in industry.