Seonju Yeo

PhD, Chemical Engineering, 2017
Sungkyunkwan University, Republic of Korea

M.S., Chemical Engineering, 2013
Sungkyunkwan University, Republic of Korea

B.S., Chemical Engineering, 2011
Sungkyunkwan University, Republic of Korea

Research Focus #1: Polymer nanocomposite materials

Materials combining improved optical transparency and mechanical strength would be highly beneficial for applications in electronic devices, display, and protective films. My research focuses on the fabrication of strong, tough, and transparent polymer composite materials with cellulose nanocrystals (CNCs). CNCs are studied as reinforcing nanofillers in polymer composites due to their intriguing properties including biocompatibility, biodegradability, abundance, low weight, and excellent mechanical strength and stiffness. Due to the presence of stiff reinforcing nanofillers, the modulus and hardness of the composite films can be 2-3 times higher than pure polymer films. Thus, these materials have great potential in replacing conventional silica-based glasses or developing anti-scratch films that combine high strength, optical transparency, and enhanced damage tolerance.

Research Focus #2: 3D printing of composite materials incorporating stimuli-responsive microcapsules

Our group has recently demonstrated a new class of stimulus-responsive transparency-changing materials based on biphasic composites. The composites are fabricated by simple emulsification of refractive index (RI) matched droplets in a silicone matrix. This RI matching technique allows us to fabricate colorful, yet transparent, silicone materials. The composites change their transparency when external stimuli, including osmotic pressure and temperature, induce a slight RI mismatch between the silicone matrix and the droplets. Along with an understanding of the optical properties of composite films, our group continues to focus on their inhomogeneous swelling behavior in DI water; this results in the formation of multifunctional composite films, which exhibit wrinkled surface, shape memory behavior, surface hardening, and strong adhesion under water. These composite materials can also be used as 3D printing inks to create more complex structures with controlled architectures and composition over a large scale.