Pressure-induced isothermal glass transition of small organic molecules

Abstract

We present a complete set of overlapping pressure-volume-temperature and dielectric relaxation data of the glass forming liquids propylene carbonate, meta-fluoroaniline, and glycerol under pressure up to 700 MPa. In all the samples a glass transition is induced by pressure at constant temperature. We compare the spectral shape of the structural relaxation process in the glass forming liquids with increasing pressure using a simple scaling for the maximum of the dielectric loss. Relaxation times measured at various temperatures and pressures can be scaled on a mastercurve by a single control parameter, the product of temperature and specific volume with a material-dependent exponent. This exponent exhibits the numerical value 4 for van der Waals liquids but is smaller for glass formers with hydrogen bonding.

Control parameter for the glass transition of glycerol evidenced by the static-field-induced nonlinear response

“…In the previous works [26][27][28] devoted to the effects of pressure , the shift δT g ( ) of T g is obtained by superimposing the polarization obtained at two different pressures. We follow this rule here: Stating that E st shifts T g by δT g (E st ) is equivalent to fulfill the equation P 1ω (E ac ,E st ,T ) = P 1ω [E ac ,0,T − δT g (E st )].…”

Observation and characterization of the vestige of the jamming transition in a thermal three-dimensional system

“…We have also shown that the dynamics of our soft colloid fluid will become very slow (that is, arrested on the time scale of our experiments) when the packing fraction is increased above φ * . This is an example of a pressure-induced glass transition [7,[49][50][51][52].…”

Communication: Relationships between Intermolecular potential, thermodynamics, and dynamic scaling in viscous systems

“…This widely debated conception [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] originates from the finding that structural relaxation time or viscosity for a given material in the vicinity of the glass transition can be plotted independently of thermodynamic conditions onto one master curve according to the scaling equation, In spite of many efforts, there is still no theory that can explain and predict the complex molecular dynamics behavior near the glass transition.…”