Thermal study of some sulphosuccinates

The thermal properties of some sulphosuccinates and their intermediates were studied by using combined dynamic thermal analysis and mass spectrometry. The temperature ranges were similar in the two methods, and a scheme of thermal decomposition of the compounds investigated was suggested. In the first temperature range of thermal decomposition of the sulphosuccinate a-rupture of the molecular ion occurs. In the second temperature range, the fragmentation proceeds in two directions: either-rupture of the ethoxylated nonylphenol, or-rupture of the acid residue of the sulphosuccinates.

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Zusammenfassung Mittels einer Kombination von dynamischer Thermoanalyse und Massenspektroskopie wurden die thermischen Eigenschaften einiger Sulfosukzinate und deren Zwischenprodukte untersucht. Im ersten Temperaturbereich der thermischen Zersetzung des Sulfosukzinates findet eine-Spaltung des Molekülions statt. Im zweiten Temperaturbereich tritt auch ein alternativer Fragmentierungsweg auf: eine-Spaltung des Säurerestes des Sulfosukzinates.

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Examination of manufacturing porous plate materials from wheat straw

The role of parameters of a barothermal processing wheat straw in the hydrolysis of polysaccharides and also their influence on the process of manufacturing porous plate materials were studied.     

Dielectric properties of 1,1,1-trifluoroethane (HFC-143a) in the liquid phase

The relative permittivity (?_r) data of 1,1,1-trifluoroethane (HFC-143a), (CAS N# 420-46-2), a hydrofluorocarbon (HFC) developed as a refrigerant that has zero ozone depletion potential, is reported. The relative permittivity of HFC-143a in the liquid phase was measured using a direct capacitance method at temperatures from T = 218 to 294 K and at pressures up to P = 15 MPa, for a frequency of 10 kHz. The uncertainty of the ?_r measurements is estimated to be better than ±1.2 × 10⁻². A complete set of tables of experimental data as a function of temperature, pressure and density, is presented that covers the dielectric property needs for most engineering applications. To study the dependence of ?_r on density and temperature on a molecular basis, the theory developed by Vedam et al. and adapted by Diguet was applied to analyse the data. The Kirkwood modification of the Onsager equation was used to obtain the value of its dipole moment in the liquid phase (μ*). The apparent dipole moment obtained was μ* = 3.293 D. The effective dipole in the liquid state predicted by the Kirkwood–Frölich theory is 2.530 D. The measured values are compared with density functional and density functional self-consistent calculations (SCIPCM) of the electronic distribution and of the dipole moment of HFC-143a. Finally, the values of the isobaric thermal expansion and isothermal compressibility were estimated from the reported measurements.     

Organomineral composite materials for drying of gaseous streams

Specific features of the synthesis of the organomineral binding agent, polyvinyl alcohol—silica sol, with high sorption activity were studied. The adsorption properties of the new material towards water were examined under equilibrium and dynamic conditions. The kinetics of water adsorption and granules based on the new material were investigated. The possibility of using the organomineral binder in technology of the preparation of granulated and block adsorbents designed for drying of gaseous streams was evaluated.     

Instability of a cholesteric liquid crystal in an ultrasonic field

A new approach to the analysis of orientation instability of a cholesteric liquid crystal in an ultrasonic field is substantiated experimentally. The approach employs the ideas of nonequilibrium hydrodynamics and takes account of the relaxational properties of the mesophase. Pis’ma Zh. éksp. Teor. Fiz. 63, No. 11, 866–870 (10 June 1996)     

Mechanism for the formation of bubble domains

Abstract

The mechanism for the formation and stabilization of acoustic bubble domains is investigated experimentally within the framework of the Akahane and Tako model which is based on the assumption of the formation of a system of defects in the layer of a cholestric liquid crystal, these defects pin the bubble domains. The theory takes no account of the interaction between bubble domains, this being valid in the case of a low density of domain packing. The correlation between the experimental results and theory is quite satisfactory, especially in the region of d/P ₀ < 1.5 where the bubble domain packing density is very low (where d is the thickness of the cholestric layer and P ₀ is the pitch of the helix).     

Synthesis and modification of carbon nanohorns structure for hyperthermic application

Single-wall carbon carcass nanoparticles (nanohorns) (CNHs) are synthesized by two methods: electric arc and electron evaporation of graphite in the inert atmosphere. Distinctions in the structures of obtained materials are revealed using electron microscopy and Raman spectroscopy. The chemical structure of the CNH surface is investigated by X-ray photoelectron and NEXAFS spectroscopy during oxidation. It is found that oxidation causes the destruction of CNH agglomerates and weakly affects the structure of graphene nets. However, these changes are sufficient for an increase in the infrared radiation absorption by the dispersion of nanohorns in water. It is shown that the efficiency of 808 nm laser heating of a CNH dispersion depends on the synthesis method and chemical modification of nanoparticles, which enables their potential use for local hyperthermia of cells of living organisms in cancer therapy.     

Amination of 3,5-dibromo-4-nitrosoanilines and 3-halo-4-nitrosophenols

Reactions of 3,5-dibromo-4-nitrosoanilines with arylamines and 3-halo-4-nitroso-phenols with alkyland arylamines result in the nucleophilic substitution of the halogen atoms.