Thermophysical and Transport Properties of the BaCl2-CsCl High Temperature Ionic Liquid Mixtures

High temperature ionic liquids (HTILs) densities and transport properties for mixtures BaCl2‑CsCl, x(BaCl2) = 0-1, have been studied as a function of composition and temperature. In terms of Arrhenius theory, the temperature correlation of all measured properties was made and discussed. Thermodynamic properties (isothermal compressibility, molecular volume, lattice energy, heat capacity, molar Gibbs energy, enthalpy and entropy) were derived for all the studied HTILs from experimental data. The viscosity isotherms show negative deviations from linearity, while conductivity isotherms have positive deviations which may be related to the formation of highly negative changed ion associated species. The evolution of the excess quantities: viscosity deviation (Δη), excess molar viscosity (ΔEη), excess molar conductivity (ΔEκ), show a very good parallelism. The linear behavior between conductivity and viscosity was determined using the fractional Walden rule and the average slope was found far from unity.

Photopolymerized superhydrophobic hybrid coating enabled by dual-purpose tetrapodal ZnO for liquid/liquid separation

The development of low-cost and scalable superhydrophobic coating methods demands viable approaches for energy-efficient separation of immiscible liquid/liquid mixtures. A scalable photoinitiated method is developed to functionalize stainless-steel mesh with...

Fuzzy Regulator for Two-Phase Gas–Liquid Pipe Flows Control

The paper presents an intelligent module to control dynamic two-phase gas–liquid mixtures pipelines flow processes. The module is intelligent because it uses the algorithm based on AI methods, namely, fuzzy logic inference, to build the fuzzy regulator concept. The developed modification has allowed to design and implement the black-box type regulator. Therefore, it is not required to determine any of the complicated computer models of the flow rig, which is unfortunately necessary when using the classic regulators. The inputs of the regulator are four linguistic variables that are decomposed into two classes and two methods of fuzzification. The first input class describes the current values of gas and liquid pipe flows, which at the same time are the controlled values manipulated to generate desired flow type. The second class of the input signals contains a current flow state, namely, its name and the name preferred by the operator flow type. This approach improves the control accuracy since the given flow type can be generated with different gas and liquid volume fractions. Those values can be optimized by knowing the current flow type. Moreover, the fuzzification algorithm used for the input signals included in the first-class covers the current crisp signal value and its trend making the inference more accurate and resistant to slight measurement system inaccuracy. This approach of defined input signals in such environments is used for the first time. Considering all mentioned methods, it is possible to generate the desired flow type by manipulating the system input signals by minimum required values. Furthermore, a flow type can be changed by adjusting only one of the input signals. As an output of the inference process, two linguistic values are received, which are fuzzified adjustment values of the liquid pump and gas flow meter. The regulator looks to be universal, and it can be adopted by multiple test and production rigs. Moreover, once configured with a dedicated rig, it can be easily operated by the non (domain) technical staff. The usage of fuzzy terms makes understanding both the control strategy working principles and the obtained results easy.

Beyond Beer’s Law: Quasi-Ideal Binary Liquid Mixtures

We have recorded attenuated total reflection infrared spectra of binary mixtures in the (quasi-)ideal systems benzene–toluene, benzene–carbon tetrachloride, and benzene–cyclohexane. We used two-dimensional correlation spectroscopy, principal component analysis, and multivariate curve resolution to analyze the data. The 2D correlation proves nonlinearities, also in spectral ranges with no obvious deviations from Beer’s approximation. The number of principal components is much higher than two and multivariate curve resolution carried out under the assumption of the presence of a third component, results in spectra which only show bands of the original components. The results negate the presence of third components, since any complex should have lower symmetry than the individual molecules and thus more and/or different infrared-active bands in the spectra. Based on Lorentz–Lorenz theory and literature values of the optical constants, we show that the nonlinearities and additional principal components are consequences of local field effects and the polarization of matter by light. Lorentz–Lorenz theory is, however, not able to explain, for example, the different blueshifts of the strong A2u band of benzene in the three mixtures. Obviously, infrared spectroscopy is sensitive to the short-range order around the molecules, which changes with content, their shapes, and their anisotropy.

Improving force field accuracy by training against condensed phase mixture properties

Developing a sufficiently accurate classical force field representation of molecules is key to realizing the full potential of molecular simulation as a route to gaining fundamental insight into a broad spectrum of chemical and biological phenomena. This is only possible, however, if the many complex interactions between molecules of different species in the system are accurately captured by the model. Historically, the intermolecular van der Waals (vdW) interactions have primarily been trained against densities and enthalpies of vaporization of pure (single-component) systems, with occasional usage of hydration free energies. In this study, we demonstrate how including physical property data of binary mixtures can better inform these parameters, encoding more information about the underlying physics of the system in complex chemical mixtures. To demonstrate this, we re-train a select number of the Lennard-Jones parameters describing the vdW interactions of the OpenFF 1.0.0 (Parsley) fixed charge force field against training sets composed of densities and enthalpies of mixing for binary liquid mixtures as well as densities and enthalpies of vaporization of pure liquid systems, and assess the performance of each of these combinations. We show that retraining against the mixture data almost universally improves the force field's ability to reproduce both pure and mixture properties, reducing some systematic errors that exist when training vdW interactions against properties of pure systems only.

INVESTIGATION OF THE COMPOSITION OF LIQUID MIXTURES FOR SMOKING. DETERMINATION OF SYNTHETIC CANNABINOIDS AND α-PVP

The purpose of the article is to highlight the possibility of quantitative identification of narcotic drugs, psychotropic substances and their analogues in the context of studying the composition of liquid mixtures for smoking (vapes), to propose a method. Methodology. A set of general scientific and special methods was used to achieve this goal. In particular, using theoretical methods (analysis, generalization, comparison, modeling), systematized theoretical materials on the problems to be solved; the state of practical elaboration of the problem is empirically determined; organizational and experimental means (diagnostic, ascertaining, formative, corrective experiment) in combination with qualitative analysis and mathematical processing of the obtained results confirmed the effectiveness of the proposed method. The reliability of the results is ensured by the use of modern instrumental physicochemical, mathematical, statistical methods of analysis, as well as software processing of experimental data. Scientific novelty. The composition of liquid mixtures for smoking was determined using physicochemical methods of research, for the first time the possibility of quantitative identification of synthetic cannabinoids and α-PVP in the composition of vapes was proved. Conclusions. The composition of liquid mixtures for smoking (vapes) was determined and the possibility of quantitative identification of narcotic drugs, psychotropic substances and their analogues using various instrumental methods based on modern scientific research, in particular the content of synthetic cannabinoids and α-PVP in liquid mixtures for smoking by thin-layer, gas chromatography and using mass spectrometry. The effectiveness of current methods of researching synthetic cannabinoids was tested on specific examples and a contribution was made to the future development of methods for studying the composition of drug-containing liquid mixtures for smoking and those containing psychotropic substances, the demand for which is currently growing on the world market and in Ukraine. A method for isolating synthetic cannabinoids and α-PVP from a solution of smoking mixtures has been developed. The general approaches to the choice of the scheme of research of synthetic narcotic drugs and psychotropic substances depending on the questions, form (liquid), type and quantity of the objects submitted for research are offered.