The dielectric relaxation behavior of ethylbenzene (EBZ) in its viscous regime is measured, and the glass transition temperature (T_g = 116 K) as well as fragility (m = 98) are determined. While the T_g of EBZ from this work is consistent with earlier results, the fragility is found much higher than what has been assumed previously. Literature data is supplemented by the present results on EBZ to compile the dynamic behavior of those glass formers that are known to form ultra-stable glasses by vapor deposition. These dynamics are contrasted with those of ethylcyclohexane, a glass former for which a comparable vapor deposition failed to produce an equally stable glassy state. In a graph that linearizes Vogel-Fulcher-Tammann behavior, i.e., the derivative of −logτ with respect to T/T_g raised to the power of −1/2 versus T/T_g, all ultra-stable glass formers fall onto one master curve in a wide temperature range, while ethylcyclohexane deviates for T ≫ T_g. This result suggests that ultra-stable glass formers share common behavior regarding the dynamics of their supercooled liquid state if scaled to their respective T_g values, and that fragility and related features are linked to the ability to form ultra-stable materials.

The transformation of vapor-deposited ultrastable glasses of indomethacin (IMC) into the supercooled liquid state near T_g is monitored by means of dielectric spectroscopy. Films with thickness between 400 and 800 nm are deposited on differential interdigitated electrode cells and their loss profiles are measured during isothermal annealing using a dual-channel impedance technique for frequencies between 0.03 and 100 Hz. All dielectric loss spectra observed during the transformation process can be explained by a volume fraction of the supercooled liquid that increases linearly with time. From the early stages of the transformation to the liquid that is formed via complete annealing of the ultrastable glass, the average dielectric relaxation time as well as the distribution of relaxation times of the liquid component are identical to those of the conventional liquid obtained by cooling the melt. The dependence of the transformation rate on the film thickness is consistent with a growth front mechanism for the direct conversion from the ultrastable glass to the equilibrium supercooled liquid. We conclude that the IMC liquid recovered from the ultrastable glass is structurally and dynamically identical to the conventional supercooled state.

A novel and simple method was described for preparation of carbonaceous adsorbent (CA) from corncob under phosphoric acid conditions. The method succeeded to introduce oxygen-containing groups onto the product surface through hydrothermal carbonization (HTC) at low temperature of 160 °C. Adsorption of methylene blue (MB) was studied systematically through the effect of pH, contact time and initial dye concentrations. The MB adsorption kinetics and isotherms experiments showed that Langmuir model and pseudo-second-order model could better describe the adsorption behavior, with a maximum adsorption capacity of MB was 140.25 mg/g. The high adsorption capacity could be ascribed to the presence of surface oxygen-containing functional groups and pore channels. In conclusion, it could be a potential adsorbent in the removal of methylene blue from wastewater.