Paper Number
SG13
Session
Solids, Glasses, and Composites
Title
The Kovacs aging signatures in colloidal glasses
Presentation Date and Time
October 12, 2015 (Monday) 4:50
Track / Room
Track 5 / Baltimore/Annapolis
Authors
- Peng, Xiaoguang (Texas Tech University, Department of Chemical Engineering)
- McKenna, Gregory B. (Texas Tech University, Chemical Engineering)
Author and Affiliation Lines
Xiaoguang Peng and Gregory B. McKenna
Department of Chemical Engineering, Texas Tech University, lubbock, TX 79409
Speaker / Presenter
Peng, Xiaoguang
Text of Abstract
In this work we have synthesized and characterized a thermo-responsive core-shell PS-PNIPAM/AA latex system [1,2] and have investigated the aging behaviors of its colloidal dispersions subsequent to temperature (or concentration)-jump perturbations using sequential creep experiments to probe the response of the colloidal system. The aging experiments were conducted in the vicinity of the glass transition concentration or temperature as evidenced by the strongly varying relaxation time with decreasing temperature (or increasing concentration). The aging results from the current colloidal glass study are compared with those expected in the Kovacs’ catalogue of experiments in structural recovery of glassy polymers, viz., intrinsic isotherms, asymmetry of approach and memory events [3]. We found that the colloidal glasses display aging behavior and time-aging time superposition is valid here. There are similarities in aging dynamics between colloidal glasses and molecular glasses, and differences also persist.
1. X. Di, X. Peng and G. B. McKenna, The Journal of Chemical Physics 140, 054903 (2014). 2. X. Peng and G. B. McKenna, Physical Review E 90, 050301(R) (2014). 3. A.J. Kovacs, Fortschritte der Hochpolymeren-Forschung, 3, 394-507 (1963).
We gratefully thank the National Science Foundation under the Grant No. CBET 1133279 and the John R. Brandford Endowment at Texas Tech University and each partially support this work.