title: Role of fragility in the formation of highly stable organic glasses.
abstract: In situ dielectric spectroscopy has been used to characterize vapor-deposited glasses of methyl-m-toluate (MMT), an organic glass former with low fragility (m = 60). Deposition near 0.84T(g) produces glasses of very high kinetic stability; these materials are comparable in stability to the most stable glasses produced from more fragile glass formers. Highly stable glasses of MMT, when annealed above T(g), transform into the supercooled liquid by a heterogeneous mechanism. A constant velocity propagating front is initiated at the free surface and controls the transformation of thin films. The transition to a bulk-dominated transformation process occurs at 5 μm, the largest length scale reported for any glass. Contrary to recent conclusions, we find that physical vapor deposition can form highly stable organic glasses across the entire range of liquid fragilities.
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: A
authors.initials: A
authors.lastname: Sepúlveda
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: M
authors.initials: M
authors.lastname: Tylinski
authors.affiliation: Department of Bioengineering, Clemson University, Clemson, South Carolina 29634, USA.
authors.forename: A
authors.initials: A
authors.lastname: Guiseppi-Elie
authors.affiliation: Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287, USA.
authors.forename: R
authors.initials: R
authors.lastname: Richert
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Ediger
mesh_terms: D001565:Benzoates / Q000737:chemistry*; D005898:Glass / Q000737:chemistry*; D007213:Indomethacin / Q000737:chemistry; D007700:Kinetics; D009281:Naphthalenes / Q000737:chemistry; D013499:Surface Properties
chemical_list: D001565:Benzoates; D009281:Naphthalenes; C007229:decalin; C034325:methyl 3-toluate; D007213:Indomethacin