Testing density scaling in nanopore-confinement for hydrogen-bonded liquid dipropylene glycol

Abstract

We have carried out dielectric relaxation studies for DPG under high-pressure conditions and confined in nanopores to check if the concept of the density scaling is able to provide a consistent picture of the viscous liquid dynamics.

Thermobaric history as a tool to govern properties of glasses: case of dipropylene glycol

“…8). 40,42,43 In our work, we confirm rather high growth rates of the glass transition temperature dT g /dP of 2PG glasses (98 K GPa À1 43 and 75 K GPa À1 42 ) at pressures up to 0.5 GPa; however, this growth slows down with increasing pressure, as evidenced by our heatings at 1 GPa and the data of previous work 40 at 1.7 GPa.…”

“…Dipropylene glycol (2PG; C 6 H 14 O 3 ) is an oligomer of propylene glycol (C 3 H 8 O 2 ), which we have studied earlier. 38,39 It is also a molecular glass-former with a glass transition temperature of 195 K, 40–43 easily achievable in our experiments. The 2PG molecule is a conglomerate of two propylene glycol molecules linked together by an oxygen atom (inset in Fig.…”

“…The T g obtained from these ultrasonic experiments were compared with the literature data and are in good agreement with the results Our experimental points obtained during heating in ultrasonic experiments are black stars. For comparison, the literature data obtained by dielectric spectroscopy are plotted as red circles 43 and a blue triangle. 40 The green dashed line is drawn by eye.…”

“…41,42 The vast majority of studies of 2PG glasses were carried out using the method of dielectric spectroscopy. 40,43,[51][52][53][54] There are a small number of works in which the glass transition of 2PG at high pressures is studied; in particular, the coefficient dT g /dP is determined. 42,43 We have studied the elastic properties of low-pressure glasses (''ordinary'' glass, LPG) of 2PG and propylene glycol.…”

“…40,43,[51][52][53][54] There are a small number of works in which the glass transition of 2PG at high pressures is studied; in particular, the coefficient dT g /dP is determined. 42,43 We have studied the elastic properties of low-pressure glasses (''ordinary'' glass, LPG) of 2PG and propylene glycol. 47 It was found that the shear modulus of 2PG is significantly lower than that of propylene glycol, which we attributed to different effective concentrations of hydrogen bonds.…”