scholarly journals Weakly Hydrated Anion Exchangers Doped with Cu2O and Cu0 Particles—Thermogravimetric Studies

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 925
Author(s):  
Elżbieta Kociołek-Balawejder ◽  
Ewa Stanisławska ◽  
Igor Mucha

Hybrid ion exchangers (HIXs) containing fine Cu2O and Cu0 particles were subjected to thermal analysis in order to determine their hygroscopic water content (with regard to their anomalously low porosity) and to determine the effect of the oxidation state of the copper atom in the deposit on the thermal properties of composite materials. Commercially available anion exchangers, Amberlite IRA 900Cl (macroreticular, M) and Amberlite IRA 402OH (gel-like, G), were used as supporting materials. M/Cu2O, G/Cu2O, M/Cu and G/Cu, containing 4.3–8.4 wt% Cu, were subjected to thermal analysis under respectively air and N2. TG/DTG curves revealed that dry M/Cu and G/Cu contained as little as 7.2% and 4.3% hygroscopic water, while M/Cu2O and G/Cu2O contained respectively 10.6% and 9.4% (Cu0 was a stronger water repellent than Cu2O). The oxidation state of the copper atom in the deposit was found to affect the amount of the forming char, and also Cu0 was found to contribute to the formation of more char than in the pyrolysis of the pure resin (the anion exchanger with no copper deposit). Under air the two kinds of particles transformed into CuO, while under N2 metallic copper and char (from the resin phase) made up the solid residue. This means that in the pyrolysis of the HIXs the inorganic phase participated in char formation and it also transformed itself (undergoing reduction when possible). The above findings provide a basis for in-depth research aimed at the innovative use of copper-containing HIXs and at obtaining usable composite materials with a designed (organic-inorganic) composition.

2020 ◽  
Author(s):  
P. S. Premkumar ◽  
K. R. Aranganayagam ◽  
G. Meena ◽  
R. Arulpriya ◽  
D. Nandhini ◽  
...  

2017 ◽  
Vol 3 (2) ◽  
pp. 43-51 ◽  
Author(s):  
Ana X. H. Yong ◽  
Graham D. Sims ◽  
Samuel J. P. Gnaniah ◽  
Stephen L. Ogin ◽  
Paul A. Smith

2020 ◽  
Author(s):  
P. Bagavac ◽  
L. Krstulović-Opara ◽  
Ž. Domazet

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Miroslav M. Pavlović ◽  
Vladan Ćosović ◽  
Zoran Janković ◽  
Jasna Stajić-Trošić ◽  
Miomir G. Pavlović

Composite materials are gaining increasing industrial applications worldwide. Composites based on polymers with conductive fillers have been recently in the focus of extensive research primarily because of their growing importance from the point of view of application. Natural polymers based on renewable materials with selected fillers can be used directly as contemporary materials in: electronics, medicine, industry, as contact conductive materials, electromagnetic and radio wave shields, photothermal optical recorders, electronic noses sensitive to certain chemicals, as well as economically acceptable catalysts. In this paper the results of experimental studies of the properties of composite materials based on lignocellulosic matrix (LC) filled with electrolytic copper powder and chemically obtained silver powder are presented. Volume fractions of metal fillers in the composite materials in tested samples were varied in the range of 1.6-30% (v/v), and the samples were prepared by compression – cold pressing. Characterization included examination of the influence of particle size and morphology on the conductivity and percolation threshold of the composites using a variety of testing techniques: SEM, TGA, DSC, particle size distribution and conductivity measurements. The thermal analysis of the prepared composites showed the improvement of the thermal characteristics of the composites. This was due to the presence of the metallic fillers which are very good thermal conductors, hence accumulating the emitted heat during TGA measurements primary to lignocellulosic matrix. On the other hand, there is no difference in the response with different metallic fillers and particles with different morphologies. Glass transition temperature is improved by 20 ºC for all the composites.


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