Welcome!

okctsui

BSc in Physics (1st class honor), University of HK; PhD in Physics, Princeton University

Department of Physics, Rm. 4455
Hong Kong University of Science and Technology
Clear Water Bay, Hong Kong, China.
Email: okctsui@ust.hk
+852-3469-2671 (off), -2703 (lab)

Our current research primarily concerns the fundamental underpinnings of the unconventional dynamics exhibited by polymers under confinement. We are particularly interested in understanding how different confining interfaces perturb the dynamics, and how their effects propagate with distance. We have devised experimental methods to probe the dynamics of polymer thin films with thicknesses down to 2 nm. We have also developed ways to measure the glass transition temperature within 1 nm from the free surface (i.e., the air/vacuum surface). For more details about our current work, please click here.

Representative Publications

1. “Mixed Equilibrium/Nonequilibrium Effects Govern Surface Mobility in Polymer Glasses”, J. Xu, A. Ghanekarade, L. Li, H. Zhu, H. Yuan, J. Yan, D. S. Simmons*, O. K. C. Tsui*, and X. Wang*, PNAS 121 (41) e2406262121 (2024). link

2. “Microscale Mobile Surface Double Layer in a Glassy Polymer”, H. Yuan, J. Yan, P. Gao, S. Kumar, O. K. C. Tsui*, Science Advances 8, eabq529S (2022). link  

3. “Strain Rate and Thickness Dependences of Elastic Modulus of Free-standing Polymer Nanometer Films”, P. M. Yiu, H. Yuan, Q. Gu, P. Gao, O. K. C. Tsui, ACS Macro Lett., 9, 1521–6 (2020). link

4. “Conflicting Confinement Effects on the Tg, Diffusivity and Effective Viscosity of Polymer Films: A Case Study with Poly(isobutyl methacrylate) on Silica and Possible Resolution”, Kung Geng, Reika Katsumata, Xuanji Yu, Heonjoo Ha, Austin R. Dulaney, Christopher J. Ellison and Ophelia K. C. Tsui, Macromolecules, 50, 609–617 (2017). link

5. “Glass Transition Dynamics and Surface Layer Mobility in Unentangled Polystyrene Films”, Z. Yang, Y. Fujii, F. K. Lee, C. -H. Lam, and O. K. C. Tsui, Science, 328, 1676-1679 (2010). link

6. “Liquid Crystal Pretilt Angle Control Using Nano-textured Surfaces”, F. S. Y. Yeung, F. C. Xie, J. Wan, F. K. Lee, O. K. C. Tsui, P. Sheng, H. S. Kwok, J. Appl. Phys., 99, 124506 (2006). link

7. “Liquid Crystal Orientation Transition on Microtextured Substrates”, Baoshe Zhang, Fuk Kay Lee, Ophelia K.C. Tsui, Ping Sheng, Phys. Rev. Lett., 91, 215501 (2003). link

8. “Effect of Interfacial Interactions on the Glass Transition of Polymer Thin Films”, O.K.C. Tsui, T.P. Russell, C.J. Hawker, Macromolecules, 34, 5535–9 (2001). link

9. “Studying Surface Glass-to-Rubber Transition Using Atomic Force Microscopic Adhesion Measurements”, O.K.C. Tsui, X. P. Wang, Jacob Y. L. Ho, T. K. Ng, Xudong Xiao, Macromolecules, 33, 4198 (2000). link

10.  “Observation of Inverted Phases in Poly(styrene-b-butadiene-b-styrene) Triblock Copolymer by Solvent-Induced Order-Disorder Phase Transition”, Qingling Zhang, O.K.C. Tsui, Binyang Du, Fajun Zhang, Tao Tang, Tianbai He, Macromolecules, 33, 9561–7 (2000). link