Modeling of the Aqueous Solubility of N-butyl-N-methyl-1-phenylpyrrolo[1,2-a] pyrazine-3-carboxamide: From Micronization to Creation of Amorphous-Crystalline Composites with a Polymer.

N-butyl-N-methyl-1-phenylpyrrole[1,2-a] pyrazine-3-carboxamide (GML-3) is a potential candidate for combination drug therapy due to its anxiolytic and antidepressant activity. The anxiolytic activity of GML-3 is comparable to diazepam. The antidepressant activity of GML-3 is comparable to amitriptyline.

Viscosity Measurement of CO-Solvent Mixtures for the Study of the Morphology and Size of Crystalline Particles Obtained Using Supercritical Antisolvent Precipitation.

The viscosity values of CO-dimethylphormamide, chloroform, methanol, isopropanol, ethyl acetate, acetone, and dimethyl sulfoxide mixtures were measured at a pressure of 150 bar and a temperature of 313 K. The correlation of the mean size of levofloxacin hydrochloride and malonic acid particles precipitated using the SAS method with the viscosity of the used CO-solvent mixtures is shown. The high viscosity of the mixtures leads to slower mixing of the solution and the antisolvent.

Supercritical fluid-assisted modification combined with the resynthesis of SmCoO as an effective tool to enhance the long-term performance of SmCoO-derived catalysts for the dry reforming of methane to syngas.

The dry reforming of methane to syngas (DRM) is of increasing significance concerning, first, the production of raw materials for commercial organic/petrochemical syntheses and for hydrogen energetic, and, second, the utilization of two most harmful greenhouse gases. Herein, new SmCoO-based DRM catalysts derived from heterometallic precursors and operated without preliminary reduction are reported. For the first time, the effect of supercritical fluids-assisted modification of the SmCoO-derived catalysts combined with the re-oxidation of spent catalysts to SmCoO onto its long-term performance was studied.

Multifunctional Elastic Nanocomposites with Extremely Low Concentrations of Single-Walled Carbon Nanotubes.

Stretchable and flexible electronics has attracted broad attention over the last years. Nanocomposites based on elastomers and carbon nanotubes are a promising material for soft electronic applications. Despite the fact that single-walled carbon nanotube (SWCNT) based nanocomposites often demonstrate superior properties, the vast majority of the studies were devoted to those based on multiwalled carbon nanotubes (MWCNTs) mainly because of their higher availability and easier processing procedures.

Adsorption of ,,','-Tetraoctyl Diglycolamide on Hypercrosslinked Polysterene from a Supercritical Carbon Dioxide Medium.

The work considers for the first time the preparation of sorbents based on hypercrosslinked polysterene (HCP) and chelating agent ,,','-tetraoctyl diglycolamide (TODGA) by impregnation in the supercritical (SC) CO medium. Such sorbents can be applied for further isolation and separation of lanthanides, actinides and other metals. They are usually prepared by impregnation in toxic organic solvents (e.

Formation of Polymer-Carbon Nanotube Composites by Two-Step Supercritical Fluid Treatment.

An approach for polymer-carbon nanotube (CNT) composite preparation is proposed based on a two-step supercritical fluid treatment. The first step, rapid expansion of a suspension (RESS) of CNTs in supercritical carbon dioxide, is used to de-bundle CNTs in order to simplify their mixing with polymer in solution. The ability of RESS pre-treatment to de-bundle CNTs and to cause significant bulk volume expansion is demonstrated.

Solute Diffusion into Polymer Swollen by Supercritical CO by High-Pressure Electron Paramagnetic Resonance Spectroscopy and Chromatography.

High-pressure electron paramagnetic resonance (EPR) was used to measure translational diffusion coefficients (D) of a TEMPONE spin probe in poly(D,L-lactide) (PDLLA) and swollen in supercritical CO. D was measured on two scales: macroscopic scale (>1 μm), by measuring spin probe uptake by the sample; and microscopic scale (<10 nm), by using concentration-dependent spectrum broadening. Both methods yield similar translational diffusion coefficients (in the range 5-10 × 10 m/s at 40-60 °C and 8-10 MPa).

Modification of Poly(4-methyl-2-pentyne) in the Supercritical Fluid Medium for Selective Membrane Separation of CO from Various Gas Mixtures.

The modification of highly permeable films of brominated 1,2-disubstituted polyacetylene, poly(4-methyl-2-penthyne), via incorporation of in situ formed butylimidazolium bromide is reported for the first time. Principal possibility and efficiency of supercritical CO and CHF use as reaction media for the corresponding process, namely for quaternization of butylimidazole by brominated polymer are revealed. As a result, we prepared new membrane materials possessing promising properties such as stability toward organic solvents, good mechanical properties and significantly improved CO-selectivity while maintaining gas permeability at high values.

Study of Dispersions of Carbon Nanotubes Modified by the Method of Rapid Expansion of Supercritical Suspensions.

The effectiveness of carbon nanotubes (CNT) deagglomeration by rapid expansion of supercritical suspensions (RESS) in nitrogen and carbon dioxide fluids was studied in this work. Two different mechanisms of deagglomeration were proposed for these two fluids at various temperature and pressure conditions. Ultrasound attenuation spectroscopy was applied as an express method of determining median diameter and aspect ratio of CNTs.

The comparison of retention behaviour of imidazoline and serotonin receptor ligands in non-aqueous hydrophilic interaction chromatography and supercritical fluid chromatography.

This work presents an investigation of retention characteristics of imidazoline and serotonin receptor ligands in non-aqueous hydrophilic interaction liquid chromatography (NA-HILIC) and supercritical fluid chromatography (SFC). The separation has been carried out by using methanol as a mobile phase modifier with addition of two types of additives (NHHCOO; NHHCOO/HCOOH) and two different stationary phases (diol; mixed-mode diol). The selectivity characteristics were observed based on S-factors, logk-logk plots and radar plots.

A case of Z/E-isomers elution order inversion caused by cosolvent percentage change in supercritical fluid chromatography.

A case of elution order inversion caused by cosolvent percentage change in supercritical fluid chromatography was observed and investigated in some detail. Z- and E-isomers of phenylisobutylketone oxime experience an elution order reversal on most columns if the mobile phase consists of CO and alcohol. At lower percentages of alcohol Z-oxime is retained less, somewhere at 2-5% coelution occurs and at larger cosolvent volume elution order reverses - Z-oxime is eluted later than E-oxime.