Our group hiking at Wissahickon Valley Park in Aug, 2022. Special thanks to Chu-Hsien for organizing this wonderful trip and those who offered rides for other people.
Congratulations on our new publication above! Please check for details at :https://pubs.acs.org/doi/10.1021/acs.jpcc.2c01214
Congratulations on our group member Chu-Hsien winning the 2022 TA award, which shows her exceptional service as a teaching assistant .
Congratulations on Sarah’s New Job at SUNY Cortland! Hope you can doing well in the future.
Check our new publication “Role of Molecular Layering in the Enhanced Mechanical Properties of Stable Glasses”
The density, degree of molecular orientation, and molecular layering of vapor-deposited stable glasses (SGs) vary with substrate temperature (Tdep) below the glass-transition temperature (Tg). Density and orientation have been suggested to be factors influencing the mechanical properties of SGs. We perform nanoindentation on two molecules which differ by only a single substituent, allowing one molecule to adopt an in-plane orientation at low Tdep. The reduced elastic modulus and hardness of both molecules show similar Tdep dependences, with enhancements of 15–20% in reduced modulus and 30–45% in hardness at Tdep ≈ 0.8Tg, where the density of vapor-deposited films is enhanced by ∼1.4% compared to that of the liquid-quenched glass. At Tdep < 0.8Tg, one of the molecules produces highly unstable glasses with in-plane orientation. However, both systems show enhanced mechanics. Both the modulus and hardness correlate with the degree of layering, which is similar in both systems despite their variable stability. We suggest that nanoindentation performed normal to the film’s surface is influenced by the tighter packing of the molecules in this direction.
More can be found at https://pubs.acs.org/doi/full/10.1021/acs.jpclett.2c00232.
Congratulations on Jocelyn Chin, the Junior student in our group for winning the 2022 Jaros Baum & Bolles Award! Good worrrrrk!
Recent research on high density thin-film glasses published by Yi and other group members is featured on PennToday
“Through the thin-film glass, researchers spot a new liquid phase. A new study on thin films of glass shows how they can be fabricated to be denser and more stable, providing a framework for new applications and devices through better design.” Congratulations Yi Jin et al! See the full story here.
The Department of Chemistry is pleased to announce that Yi-Chih Lin will join the University of Texas at Austin in Fall 2021 as an assistant professor. See the full story here.
Zahra Fakhraai is awarded the Dean’s Award for Mentorship of Undergraduate Research for 2021. Congratulations!