Relationship between the morphology and combustibility of fluorinated polyamide composites

The effect that polyfluorinated alcohols immobilized on montmorillonite support exert on structuralmorphological characteristics and combustibility of polymer composites was studied with 1,1,9-trihydroperfluoro- 1-nonanol as example. The relationship between the flame resistance of this heterochain polymer and its morphology was revealed by X-ray diffraction analysis, electron microscopy, DSC, and Fourier IR spectroscopy. This relationship is associated with the reorganization of the crystal and molecular structure under the influence of fluorinated organoclay, ensuring increased degree of crystallinity and redistribution of the fractions of α- and γ-crystalline forms in the polymorphic composition of polycaprolactam, making its supramolecular structure more perfect, and favoring preparation of a fluorinated material of decreased combustibility.

     

Application of a Spectroscopic Method for Noninvasive Determination of Glucose Content in Blood

Russian Physics Journal -     

Dynamics of the Thermal Instability Evolution in Dielectric Breakdown

A mathematical model of the dynamics of temperature, electric field strength, and charge density in thermal dielectric breakdown is examined. The characteristics of the evolution of a thermal instability initiated by a local temperature disturbance are studied by numerical modeling. The conditions of initiation and growth of an electrothermal structure resulting in the formation of a highly conductive channel and shunting of the dielectrics current are identified.     

Noncommutative Integrability of the Klein–Gordon and Dirac Equations in (2+1)-Dimensional Spacetime

Russian Physics Journal - Noncommutative integration of the Klein–Gordon and Dirac relativistic wave equations in (2+1)-dimensional Minkowski space is considered. It is shown that for all...     

Heterometallic heterochalcogenmethylarsenide clusters: Synthesis,molecular structures,and thermolysis

Reactions of the arsinechalcogenide complexes [Fe₃(μ₃-X)(μ₃-AsCH₃)(CO)₉] (X = Se (Ia) or Te (Ib)) with (PPh₃)₂Pt(PhC≡CPh) (transmetalation reaction) and Cp₂Cr₂(SCME₃)₂S (Cp = π-C₅H₅) (photochemical reaction) gave the heterometallic (heterochalcogen)(methylarsine) clusters [(PPh₃)₂Pt(μ₃-X)(μ₃-AsCH₃)Fe₂(CO)₆] (II and III, respectively), as well as Fe₃(μ₃-X)(μ₃-AsCH₃)(CO)₈(C₅H₅)₂Cr₂(μ₃-S)(μ₂-S ^t Bu)₂ (IV and V, respectively). The structures of complexes II, IV, and V were determined by X-ray diffraction analysis. Thermolysis of all the complexes yielded no metal carbides or oxides.     

Polyphenylens,Cross-Linked Through Pd-Carbene Complexes Formation,for Catalysis in Suzuki-Miyaura Reactions

Polyphenylenes supported N-heterocyclic carbene Pd-complexes were synthesized for catalysis of cross-coupling Suzuki-Miyaura reactions. Starting polyphenylenes were prepared by cyclocondensation reaction of diacetylaromatic with monoacetylaromatic compounds. N-metylimidazole has been involved to the polymer through the mono-functional acetyl monomer, in which in p-position to acetyl group the group of haloalkyl was situated, and haloalkyl group interacted with N-methylimidazole. N-heterocyclic carbene complexes of Pd were synthesized usually by the reaction of imidazolium salts with the salts of transition metals in the presence of a base, obtaining the complex (N-heterocyclic carbene)₂PdX₂. The catalysis reaction was carried out between arylhalides (iodo- or bromobenzene) and phenylboronic acid with the presence of 1 mol% of Pd. The yields of biphenyl are from 70 to 95%, which is comparable with homogeneous catalysis.     

Effect of fluoride anions on gramicidin photoinactivation sensitized by sulfonated aluminum phthalocyanines.

Interaction of potent photodynamic agents, sulfonated aluminum phthalocyanines (AlPcSn where n is a number of sulfonic groups), with biological membranes was studied here using model systems: sensitized photoinactivation of gramicidin channels in planar lipid bilayers and adsorption on lipid monolayers. Fluoride anions known to form complexes with aluminum were found to inhibit both the adsorption of aluminum phthalocyanines on lipid monolayers, as measured with a Langmuir trough by surface pressure and surface potential changes, and photodynamic efficacy of the dyes, as studied by gramicidin channel photoinactivation. The similar effects were caused by the alkalinization of the medium. Fluoride anions appeared to be much more effective in the case of AlPcS4 as compared to AlPcS3. The suppression of the photodynamic potency of aluminum phthalocyanines was attributed to desorption of the dyes from lipid bilayers induced by fluoride or hydroxyl ions. With AlPcS4 an enhancement of the dye aggregation leading to a decrease in the sensitizing activity was probably involved in the fluoride effect as revealed by absorption and fluorescence spectral measurements. Capillary electrophoresis was employed to understand the mechanism of the dye desorption. The results of these experiments indicated that the reduction in the membrane affinity was associated with an increase in the negative charge of the dye molecules due to the binding of fluoride or hydroxyl ions.