19 research outputs found
On the way to highly emissive materials: increasing rigidity by introduction of furan moiety in Co-oligomers
On the way to highly emissive materials: increasing rigidity by introduction of furan moiety in Co-oligomers
Prospects for Establishment of Technological Complexes in Machine Building Industry on The Basis of Electromechatronic Propulsion Systems
The authors consider prospects for technological complex establishment in machine building industry on the basis of electromechatronic propulsion systems for production of innovative products with different novelty levels: world, state, brunch, region, etc
A Method and a Device for Diagnostics of the Functional State of Peripheral Vessels of the Upper Limbs
The article suggests a method and a device for diagnostics of the functional state of peripheral vessels of the upper limbs, which provide identification of angiospastic disorders with a lower probability of falsenegative result, allowing thereby the quality of diagnostics to be improved. The suggested approach is based on combined application of laser Doppler flowmetry and contact thermometry during an occlusion test. The obtained results can be used in various fields of medicine for the development of multifunctional noninvasive diagnostic systems for the diagnosis and prevention of diseases associated with changes in the functional state of peripheral vessels
Long-range exciton transport in brightly fluorescent furan/phenylene co-oligomer crystals
The design of light-emitting crystalline organic semiconductors for optoelectronic applications requires a thorough understanding of the singlet exciton transport process. In this study, we show that the singlet exciton diffusion length in a promising semiconductor crystal based on furan/phenylene co-oligomers is 24 nm. To achieve this, we employed the photoluminescence quenching technique using a specially synthesized quencher, which is a long furan/phenylene co-oligomer that was facilely implanted into the host crystal lattice. Extensive Monte-Carlo simulations, exciton-exciton annihilation experiments and numerical modelling fully supported our findings. We further demonstrated the high potential of the furan/phenylene co-oligomer crystals for light-emitting applications by fabricating solution-processed organic light emitting transistors
N-Heterocyclic Molecules as Potential Liquid Organic Hydrogen Carriers: Reaction Routes and Dehydrogenation Efficacy
This study is focused on the development of liquid organic hydrogen carriers (LOHC) based on N-heterocyclic compounds. These LOHC-substrates are attractive for their lower hydrogen extraction temperature compared to cycloalkanes, which is caused by the low enthalpy of the dehydrogenation reaction of the N-heterocyclic compounds. The low hydrogen extraction temperature, as well as the low volatility of the heterocycles, provide high purity hydrogen from the reaction. Under similar reaction conditions, the comparison of the efficacy of three promising heterocycles (1-methyl-octahydroindole (8HMI), tetradecahydrophenazine and decahydroquinoline) was carried out in the presence of palladium-containing catalysts. As a result, the advantages of using catalysts supported by alumina, and the high perspectivity of the 8MHI application as a LOHC-substrate, were shown. The dehydrogenation of 8HMI in the presence of 1 wt.% Pd/Al2O3 allowed for reaching a 100% yield in hydrogen under the conditions of the standard catalytic test (1 h, 240 Β°C). In order to study the high reactivity of 8HMI, thermodynamic dehydrogenation reaction profiles were computationally evaluated, which showed that 8HMI was the most energetically preferred in the field of hydrogen storage from the studied heterocyclic compounds
Dissertation councils of the future: 5 Γ 7 β quality
This article analyzes the situation prevailing in the system of preparation and thesis defense in Russia. The authors offer their own concept of improving the system of training of highly qualified personnel in Russia
Way to Highly Emissive Materials: Increase of Rigidity by Introduction of a Furan Moiety in Co-Oligomers
Rigid
linear organic co-oligomers are prospective materials for organic
optoelectronics. In this work, we explored intramolecular factors
affecting the torsional rigidity and its influence on optoelectronic
properties of the alternating furan/phenylene and thiophene/phenylene
co-oligomers in both ground and first singlet excited states. A furan/phenylene
co-oligomer exhibits almost twice as high torsional rigidity than
its thiophene analogue. The effect of intramolecular OΒ·Β·Β·H
and SΒ·Β·Β·H interactions on torsional barriers was found
to be negligible as compared with the conjugation efficiency. The
higher torsional rigidity of furan and thiophene co-oligomers has
been proven to be reflected in the fine structure of the UVβvis
absorption spectrum of the former. The increase of furan co-oligomer
rigidity as compared with its thiophene analogue lowers reorganization
energy for hole, electron, and exciton transfer. Remarkably the substitution
of thiophene by furan lowers by almost 20 times the reorganization
energy for exciton transfer. A noteworthy finding was also that in
furan co-oligomer the higher rigidity was suggested to hinder βin
moleculeβ photoluminescence quenching due to a possible conical
intersection between bright state S<sub>1</sub> and the T<sub>3</sub> excited state. Therefore, tuning of torsional rigidity impacts emission
and charge transport properties, being a very powerful tool on the
way to high performance emissive organic semiconductors
Hydrogen Production by N-Heterocycle Dehydrogenation over Pd Supported on Aerogel-Prepared Mg-Al Oxides
Tetradecahydrophenazine (14HP) is a nitrogen-containing heterocycle compound with a high content of hydrogen that can be released during its dehydrogenation to phenazine (P). The high stability of the 14HP/P pair and relatively low dehydrogenation temperature make 14HP a promising organic hydrogen carrier. This manuscript is devoted to the investigation of hydrogen production by 14HP dehydrogenation over Pd supported on a series of magnesium-aluminum oxides prepared by the aerogel method. This technique made it possible to synthesize catalyst supports characterized by a high surface area and high concentration of surface active sites where active transition metals could be stabilized in a finely dispersed state. The synthesized aerogels had high specific surface areas and pore volumes. A surface area as high as 600 m2/g after calcination at 500 °C was observed for the mixed aerogel with an Mg:Al ratio of 1:4. An increase in the concentration of acidic electron-acceptor sites determined by EPR on the surface of the mixed magnesium-aluminum oxide supports with a high surface area prepared by the aerogel method was found to result in higher hydrogen production due to the faster dehydrogenation of sterically hindered nitrogen-containing tetradecahydrophenazine heterocycles
Hydrogen Production by N-Heterocycle Dehydrogenation over Pd Supported on Aerogel-Prepared Mg-Al Oxides
Tetradecahydrophenazine (14HP) is a nitrogen-containing heterocycle compound with a high content of hydrogen that can be released during its dehydrogenation to phenazine (P). The high stability of the 14HP/P pair and relatively low dehydrogenation temperature make 14HP a promising organic hydrogen carrier. This manuscript is devoted to the investigation of hydrogen production by 14HP dehydrogenation over Pd supported on a series of magnesium-aluminum oxides prepared by the aerogel method. This technique made it possible to synthesize catalyst supports characterized by a high surface area and high concentration of surface active sites where active transition metals could be stabilized in a finely dispersed state. The synthesized aerogels had high specific surface areas and pore volumes. A surface area as high as 600 m2/g after calcination at 500 Β°C was observed for the mixed aerogel with an Mg:Al ratio of 1:4. An increase in the concentration of acidic electron-acceptor sites determined by EPR on the surface of the mixed magnesium-aluminum oxide supports with a high surface area prepared by the aerogel method was found to result in higher hydrogen production due to the faster dehydrogenation of sterically hindered nitrogen-containing tetradecahydrophenazine heterocycles