The heat transfer oils dibenzyltoluene and benzyltoluene are promising materials as a new class of liquid organic hydrogen carrier compounds (LOHC). Thermophysical properties (heat capacity, density, viscosity, and surface tension) of the commercially available thermofluids Marlothem LH (benzyltoluene) and Marlotherm SH (dibenzyltoluene) and their completely hydrogenated derivatives were measured. Thermochemical properties (enthalpies of combustion and enthalpies of vaporization) were derived from experiments. Gas-phase molar enthalpies of formation were derived and validated with group-additivity and high-level quantum chemical calculations. Enthalpies of the hydrogenation/dehydrogenation reactions of the LOHC pairs under study were derived.
Ionic systems with enhanced proton conductivity are widely viewed as promising electrolytes in fuel cells and batteries. Nevertheless, a major challenge toward their commercial applications is determination of the factors controlling the fast proton hopping in anhydrous conditions. To address this issue, we have studied novel proton-conducting materials formed via a chemical reaction of lidocaine base with a series of acids characterized by a various number of proton-active sites. From ambient and high pressure experimental data, we have found that there are fundamental differences in the conducting properties of the examined salts.On the other hand, DFT calculations revealed that the internal proton hopping within the cation structure strongly affects the pathways of mobility of the charge carrier. These findings offer a 2 fresh look on the Grotthuss-type mechanism in protic ionic glasses as well as provide new ideas for the design of anhydrous materials with exceptionally high proton conductivity.
The thermochemical properties available in the literature for adenine and cytosine are in disarray. A new condensed phase standard (p° = 0.1 MPa) molar enthalpy of formation at T = 298.15 K was measured by using combustion calorimetry. New molar enthalpies of sublimation were derived from the temperature dependence of vapor pressure measured by transpiration and by the quarz-crystal microbalance technique. The heat capacities of crystalline adenine and cytosine were measured by temperature-modulated DSC. Thermodynamic data on adenine and cytosine available in the literature were collected, evaluated, and combined with our experimental results. Thus, the evaluated collection of data together with the new experimental results reported here has helped to resolve contradictions in the available enthalpies of formation. A set of reliable thermochemical data is recommended for adenine and cytosine for further thermochemical calculations. Quantum-chemical calculations of the gas phase molar enthalpies of formation of adenine and cytosine have been performed by using the G4 method and results were in excellent agreement with the recommended experimental data. The standard molar entropies of formation and the standard molar Gibbs functions of formation in crystal and gas state have been calculated. Experimental vapor-pressure data measured in this work were used to estimate pure-component PC-SAFT parameters. This allowed modeling solubility of adenine and cytosine in water over the temperature interval 278-310 K.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.