OBTAINING SOME THERMOD AINING SOME THERMODYNAMIC PARAMETERS CONTAINING ME AINING METACRYLATE AND ALL TE AND ALLYL GROUPS CON YL GROUPS CONTAINING IN COMPOSITION

2019 ◽  
Vol 2019 (1) ◽  
pp. 44-49
Author(s):  
M Abdukakhkharova ◽  
◽  
A Ismailov ◽  
U Mirzaev ◽  
R Ismailov

The article discusses the preparation of some thermodynamic parameters characterizing the final product of complex radical polymerization of amino alkyl acrylate derivatives containing both methacrylate and alkyl groups of low molecular weight compounds with electron acceptors - polymerization initiators at temperatures that exclude thermal decomposition of the initiators themselves. The equilibrium constant of the complication reaction and the molar extinction coefficient of the complex were determined by graphically solving the Bеneshe-Hildebrand equation, the heats of complex formation, entropy, Gibbs energy were found, and the elemental composition of low molecular weight and high molecular weight substances was determined. As can be seen from the studies, the molar extinction coefficient of the complex practically does not depend on temperature, and the equilibrium constant of the complexation reaction even in a narrow temperature range (283–293 K) increases with increasing temperature. The structure and composition of the synthesized monomeric and polymer salt were also considered in the work, and confirmed by IR-spectroscopy and analysis of elemental composition, the obtained spectroscopic data showed that the unit of the formed polymer corresponds in composition and structure to the monomeric quaternary salt, and the allyl bond in the polymers is preserved. It can be seen from the studies that, with an increase in the concentration of both the monomer and the initiator, the reaction rate naturally increases.

RSC Advances ◽  
2015 ◽  
Vol 5 (94) ◽  
pp. 76666-76669 ◽  
Author(s):  
Mei-Ju Su ◽  
Jin-Hua Huang ◽  
Li-Peng Zhang ◽  
Qian-Qian Zhang ◽  
Chuan-Lang Zhan ◽  
...  

Two small molecular quinoidal thiophene dyes, featuring low molecular weight, high molar extinction coefficient, and narrow band-gap, have been synthesized as donors for organic photovoltaic cells, giving a best power conversion efficiency of 5.12%.


2020 ◽  
Vol 10 (24) ◽  
pp. 8995
Author(s):  
Chuang Cheng-Wen ◽  
Hsu Liang-Fong ◽  
Tsai Hsiang-Chun ◽  
Liu Yung-Yu ◽  
Huang Wei-Shiang ◽  
...  

In rivers, the distribution and reactivity of heavy metals (HMs) are affected by their binding affinity with sediment dissolved organic matter (DOM) and particulate organic matter (POM). The HM-OM binding affinity affected by the interaction between DOM and POM is not well studied. This study investigated the Ni binding affinity to size-fractioned overlaying water DOM and alkaline extracted sediment POM solution (AEOM). The DOM/AEOM filtrates (<0.45 μm) were sequentially separated into five nominal molecular weight (MW) solutions. The AEOM optical indicators had lower autochthonous, higher terrestrial sources, and lower aromaticity than the DOM. The Ni mass (72.3 ± 6.4%) was primarily distributed in the low molecular weight DOM (<1 kDa), whereas the Ni (93.5 ± 0.4%) and organic carbon (OC) mass (85.3 ± 1.0%) were predominantly distributed in the high molecular weight AEOM. The Ni and DOM binding affinity, ([Ni]/[DOC])DOM ratio ranging from 0.76 to 27.32 μmol/g-C, was significantly higher than the ([Ni]/[DOC])AEOM ratios, which ranged from 0.64 to 2.64 μmol/g-C. The ([Ni]/[DOC])AEOM ratio correlated significantly with the selected optical indicators (r = 0.87–0.92, p < 0.001), but the ([Ni]/[DOC])DOM ratio correlated weakly with the optical indicators (r = 0.13–0.40, p > 0.05). In the present study, the Ni binding affinity with size-fractioned DOM/AEOM agrees with the hypothesis of the DOM and POM exchange conceptual model in sediment. The POM underwent a hydrolysis/oxidation process; hence, AEOM had a high molecular weight and stable chemical composition and structure. The Ni mainly attached to the high molecular weight AEOM and the ([Ni]/[DOC])AEOM ratios had a strong correlation with the AEOM optical indicators. In contrast, DOM had a high ([Ni]/[DOC])DOM ratio in low molecular weight DOM.


Author(s):  
G.K.W. Balkau ◽  
E. Bez ◽  
J.L. Farrant

The earliest account of the contamination of electron microscope specimens by the deposition of carbonaceous material during electron irradiation was published in 1947 by Watson who was then working in Canada. It was soon established that this carbonaceous material is formed from organic vapours, and it is now recognized that the principal source is the oil-sealed rotary pumps which provide the backing vacuum. It has been shown that the organic vapours consist of low molecular weight fragments of oil molecules which have been degraded at hot spots produced by friction between the vanes and the surfaces on which they slide. As satisfactory oil-free pumps are unavailable, it is standard electron microscope practice to reduce the partial pressure of organic vapours in the microscope in the vicinity of the specimen by using liquid-nitrogen cooled anti-contamination devices. Traps of this type are sufficient to reduce the contamination rate to about 0.1 Å per min, which is tolerable for many investigations.


1998 ◽  
Vol 1 (5) ◽  
pp. 166-174 ◽  
Author(s):  
Evelyn R Hermes De Santis ◽  
Betsy S Laumeister ◽  
Vidhu Bansal ◽  
Vandana Kataria ◽  
Preeti Loomba ◽  
...  

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