Τμήμα Επιστήμης & Μηχανικής Υλικών

Owing to the kinetic nature of the glass transition, the ability to significantly alter the properties of amorphous solids by the typical routes to the vitreous state is restricted. For instance, an order of magnitude change in the cooling rate merely modifies the value of the glass transition temperature (Tg) by a few degrees. Here we show that matrix-assisted pulsed laser evaporation (MAPLE) can be used to form ultrastable and nanostructured glassy polymer films which, relative to the standard poly(methyl methacrylate) glass formed on cooling at standard rates, are 40% less dense, have a 40 K higher Tg, and exhibit a two orders of magnitude enhancement in kinetic stability at high temperatures. The unique set of properties of MAPLE-deposited glasses may make them attractive in technologies where weight and stability are central design issues.

From:
Yunlong Guo, Anatoli Morozov, Dirk Schneider, Jae Woo Chung, Chuan Zhang,
Maike Waldmann, Nan Yao, George Fytas, Craig B. Arnold,
Rodney D. Priestley
Ultrastable nanostructured polymer glasses“,
Nature Materials
11, 337-343 (2012).