title: Bond-induced ergodicity breakdown in reactive mixtures.
abstract: We have studied by inelastic x-ray scattering, at wave vectors 1 nm < or =q< or =15 nm(-1), the high-frequency dynamics of epoxy-amine mixtures as the monomers irreversibly polymerize. We find that chemical bonding, while inducing molecular ordering on a mesoscopic length scale, also efficiently realizes the mechanism of dynamical arrest described by the mode-coupling theory, as manifested by a cusp singularity in the behavior of the nonergodicity factor as a function of the number of chemical bonds. These results confront positively the mode-coupling theory with a new control parameter.
authors.affiliation: INFM CRS-SOFT, c/o Università di Roma La Sapienza, P. A. Moro 2, I-00185 Roma, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Corezzi
authors.forename: L
authors.initials: L
authors.lastname: Comez
authors.forename: G
authors.initials: G
authors.lastname: Monaco
authors.forename: R
authors.initials: R
authors.lastname: Verbeni
authors.forename: D
authors.initials: D
authors.lastname: Fioretto