ULTRASONIC STUDIES OF THE POLYMER STRUCTURE OF THE CHALCOGENIDE GLASSES

1981 ◽  
Vol 42 (C4) ◽  
pp. C4-955-C4-958
Author(s):  
V. A. Ratobylskaja ◽  
L. A. Simonova
1981 ◽  
Vol 42 (C4) ◽  
pp. C4-931-C4-934 ◽  
Author(s):  
M. F. Kotkata ◽  
M.B. El-den

1981 ◽  
Vol 42 (C4) ◽  
pp. C4-579-C4-582
Author(s):  
T. Shiraishi ◽  
D. Adler

1981 ◽  
Vol 42 (C4) ◽  
pp. C4-383-C4-386 ◽  
Author(s):  
S. G. Bishop ◽  
B. V. Shanabrook ◽  
U. Strom ◽  
P. C. Taylor

Author(s):  
А. А. Горват ◽  
В. М. Кришеник ◽  
А. Е. Кріштофорій ◽  
В. В. Мінькович ◽  
О. А. Молнар

2015 ◽  
Vol 11 (1) ◽  
pp. 2914-2917
Author(s):  
Alekberov R.I ◽  
Mekhtiyeva S.I ◽  
Isayev A.I ◽  
Mammadova H.I.

In work investigated with method IR of spectroscopy of amorphous selenium andsystem Se95As5 containing impurity samarium. It is certain that, in IR a spectrum of amorphous selenium due to hypervalent defects maxima with different intensity are observed in 230 and 270 cm-1.Increase of the concentration of impurity samarium in spectrum Se95As5, the maximum arises with 400cm-1frequency which, are connected with SmSe3 structural elements.


Author(s):  
Д.Л. Байдаков

Методом химического нанесения из растворов халькогенидных стекол в н-бутиламине получены многокомпонентные халькогенидные пленки CuI-As2Se3, CuI-PbI2-As2Se3, CuI-SbI3-As2Se3, CuI-SbI3-PbI2-As2Se3. Синтез многокомпонентных медьсодержащих халькогенидных стекол, использовавшихся для нанесения пленок, проводили методом вакуумной плавки в кварцевых ампулах при температуре 400…950 °С и остаточном давлении не более 0,13 Па. Закалку стекол производили от 600 °С в воду со льдом с разливом расплава в ампуле. Навеску стекла размельчали в порошок и кипятили в н-бутиламине до полного растворения. Для предотвращения процессов окисления, нанесение и отжиг пленок проводили в атмосфере химически инертного азота. Подложку помещали на устройство для вращения, наносили на нее раствор и вращали подложку со скоростью несколько тысяч оборотов в минуту. Отжиг пленок проводили при температуре 100 °С в течение 1 ч. Измерение электропроводности полученных пленок проводили на постоянном и переменном токе в зависимости от значений электропроводности в температурном интервале 20…100 °С. Измерение коэффициентов диффузии проводили абсорбционным методом. Из диффузионных экспериментов определены значения коэффициентов диффузии катионов изотопа 110mAg в медьсодержащих халькогенидных пленках. Установлено, что значения коэффициентов диффузии ионов Ag+ в химически нанесенных пленках и исходных стеклах практически не различаются. Аналогию значений коэффициентов диффузии изотопа 110mAg в халькогенидных стеклах и пленках на их основе можно объяснить сохранением полимерной сетки связей халькогенидных стекол при их растворении в органических основаниях (аминах). В процессе нанесения и формирования пленок полимерная (макромолекулярная) структура раствора халькогенидных стекол сохраняется. The method of chemical deposition from solutions of chalcogenide glasses in n-butyl amine obtained multicomponent chalcogenide films CuI-As2Se3, CuI-PbI2-As2Se3, CuI-SbI3-As2Se3, CuI-SbI3-PbI2-As2Se3. Synthesis of copper multicomponent chalcogenide glasses, used for film deposition was carried out by vacuum melting in quartz ampoule at a temperature of 400…950 °C and a residual pressure of not more than 0.13 Pa. The temperature of glass produced from the 600 °C to the ice water spill of the melt in the ampoule. Weigh glass comminuted to a powder and heated in n-butylamine until complete dissolution. To prevent oxidation, deposition and annealing of the films was carried out in an atmosphere of nitrogen chemically inert. The substrate is placed on a device for rotating, it was applied to the solution and the substrate was rotated at a speed of several thousand revolutions per minute. Annealing of the films was carried out at 100 °C for 1 hour. Measurement of the electrical conductivity of the obtained films was conducted at a constant current and variable depending on the conductivity values ​​in the temperature range from 20 to 100 °C. Measurement of diffusion coefficients was performed according to the absorption method. From diffusion experiments, the values ​​of the diffusion coefficients 110mAg isotope cations in copper chalcogenide films. It was found that the values ​​of the diffusion coefficients of the ions Ag+ in a chemically deposited films and the original glasses are indistinguishable. The analogy of the diffusion coefficient values ​​110mAg isotope in chalcogenide glasses and films based on them can be attributed to the preservation of the polymer network connections chalcogenide glasses when dissolved in organic bases (amines). During application and film formation the polymer (macromolecular) structure of chalcogenide glasses of the solution is maintained.


2017 ◽  
Vol 14 (6) ◽  
pp. 778-784 ◽  
Author(s):  
Joanna Brzeska

Background: Cross-linking structure of polyurethanes determines no degradability of these materials. However, introducing the hydrolysable substrates (of natural or synthetic origin) into the cross-linked polyurethanes structure makes them biodegradable. Moreover compounds (such as polycaprolactone triol, glycerin, lysine triisocyanate, etc.) that are used for polyurethane cross-linking are degraded in non-toxic products. All these kinds of compounds can be introduced into soft or hard segments via urethane bonds. Objective: The review focuses on kind of multifunctional polyols and isocyanates, and low molecular crosslinkers used for cross-linked polyurethanes obtaining. These compounds are natural substrates (in the native state or after modification) or are synthetic compounds with degradable linkages. They belong to polyesters, plant oils, proteins, saccharides, and others (e.g. lignocellulosic materials), and they are synthesized chemically or via biosynthesis by algae, plants, microorganisms, and by animals. Conclusion: Incorporation of degradable groups (such as ester moieties) into the polymer structure, and using of substrates with the structure known and metabolized by microorganisms for soft or hard segments building, facilitate degradation of cross-linked polyurethanes.


Sign in / Sign up

Export Citation Format

Share Document