Physical Aging in a Colloidal Glass Subjected to Concentration

Submitted for the MAR15 Meeting of The American Physical Society Physical Aging in a Colloidal Glass Subjected to Concentration Jump Conditions1 XIAOGUANG PENG, GREGORY B. MCKENNA, Department of Chemical Engineering, Texas Tech University, Lubbock, 79409, Texas, USA — We have prepared a thermo-sensitive core-shell PS-PNIPAM/AA latex system and have investigated the aging dynamics of its colloidal dispersions subsequent to the temperature (or concentration)-jump perturbations using sequential creep experiments to probe the response of the system. The aging experiments were performed 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 [1]. We found that colloidal glass displays 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] A.J. Kovacs, Fortschritte der Hochpolymeren-Forschung, 3, 394-507 (1963). 1We 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. Xiaoguang Peng Department of Chemical Engineering, Texas Tech University, Lubbock, 79409, Texas, USA Date submitted: 12 Nov 2014 Electronic form version 1.4