Effect of the kind of cupric compound deposit on thermal decomposition of anion exchangers

Kociołek‐Balawejder, Elżbieta; Stanisławska, Ewa; Mucha, Igor

doi:10.1016/j.tca.2020.178812

Cited by 7 publications

(18 citation statements)

References 33 publications

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“…It is apparent that the HIXs with Cu 0 particles contained considerably less hydration bound water than the HIXs with Cu 2 O particles. This content for M/Cu (7.2%) and G/Cu (4.3%) was anomalously low as the pure resins (both anion exchangers) had about 15% hygroscopic water content [ 30 , 31 ]. Typically, in the parent resins (M, G) the functional ionogenic groups were surrounded by water molecules, which is referred to as solvation.…”

Section: Resultsmentioning

confidence: 99%

“…One of the causes of the higher hygroscopicity of M/Cu 2 O and G/Cu 2 O in comparison with M/Cu and G/Cu could be the presence of functional groups in the OH − form, which shows a very strong affinity for water [ 39 ]. It is worth mentioning than the HIXs with Cu 2 O particles contained clearly less hydration bound water (about 10%) than the HIXs with CuO particles (about 13%) [ 31 ].…”

Section: Resultsmentioning

confidence: 99%

“…Recently we have undertaken in-depth studies into the thermal decomposition of HIXs. So far the studies have concentrated on anion exchangers containing particles of hydrated iron oxide (FeOOH) [ 30 ] and different cupric compounds (CuO, Cu(OH) 2 and Cu 4 (OH) 6 SO 4 ) in their porous matrix [ 31 ]. In comparison with the pure resins, the particles have been found to: (a) lower the incineration end temperature while raising the pyrolysis end temperature, (b) change the temperature ranges of the individual ion exchanger decomposition stages, (c) react with the char arising from organic matter (the anion exchanger) in the course of pyrolysis.…”

Section: Introductionmentioning

confidence: 99%

“…In comparison with the pure resins, the particles have been found to: (a) lower the incineration end temperature while raising the pyrolysis end temperature, (b) change the temperature ranges of the individual ion exchanger decomposition stages, (c) react with the char arising from organic matter (the anion exchanger) in the course of pyrolysis. Thanks to this latter property, stemming from the chemical structure of the inorganic phase (more precisely from its reducibility), it was possible to obtain more char than from the pyrolysis of the pure resin, and the char contained the chemically transformed (reduced when possible) inorganic phase [ 31 ]. Consequently, the pyrolysis of a HIX containing FeOOH yielded a carbonaceous material with Fe 3 O 4 [ 30 ], the pyrolysis of a HIX containing Cu 4 (OH) 6 SO 4 (brochantite) yielded a carbonaceous material with Cu 2 S and the pyrolysis of a HIX containing CuO yielded a carbonaceous material with metallic copper [ 31 ].…”

Section: Introductionmentioning

confidence: 99%

“…Thanks to this latter property, stemming from the chemical structure of the inorganic phase (more precisely from its reducibility), it was possible to obtain more char than from the pyrolysis of the pure resin, and the char contained the chemically transformed (reduced when possible) inorganic phase [ 31 ]. Consequently, the pyrolysis of a HIX containing FeOOH yielded a carbonaceous material with Fe 3 O 4 [ 30 ], the pyrolysis of a HIX containing Cu 4 (OH) 6 SO 4 (brochantite) yielded a carbonaceous material with Cu 2 S and the pyrolysis of a HIX containing CuO yielded a carbonaceous material with metallic copper [ 31 ]. This means that by pyrolyzing HIXs one can obtain unconventional and potentially usable carbon char-inorganic particle composites with a designable chemical composition.…”

Section: Introductionmentioning

confidence: 99%

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

2021

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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.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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

2021

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The influence of CuxS particles on the thermal decomposition of anion exchangers

Kociołek-Balawejder,

Mucha

2024

J Therm Anal Calorim

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Due to the versality, surface imperfections and diverse redox chemistry of CuxS, hybrid ion exchangers (HIXs) containing these particles are an interesting object of research, including thermal transformation. The composite materials used for testing were strongly basic anion exchangers, with macroreticular (M) and gel-type structure (G), containing in the poly (styrene/divinylbenzene) skeleton fine particles of covellite/brochantite (M1), covellite (M2), covellite/digenite/djurleite (G1) and covellite/digenite (G2). The prepared HIXs contained 12–16 mass% S + Cu. They were subjected to thermal analysis under air and N2 to identify the role of the inorganic phase in decomposition of the polymeric phase. The results were discussed on the basis of the TG/DTG curves and X-ray diffraction (XRD) patterns of the solid residues (CuO after combustion, carbon/Cu2S after pyrolysis). It was found that CuxS in the resin phase exhibited oxidative activity promoting the combustion process. The polymeric skeleton of HIXs decomposed in air at a much lower temperature compared to pure resins (400 vs 600 °C). The TG/DTG curves had a model shape, three separate conversions occurring in a narrow temperature range, which indicated sequential decomposition. The low consumption of hydrogen for the reduction of CuxS to Cu2S during pyrolysis was not conducive to condensation of alkyl radicals and increase of the mass of carbon matter. The results advance the understanding of the effect of copper/sulfur-containing fine particles on the thermal decomposition of anion exchanger and can be useful in preparation of multifunctional carbon-containing composite materials.

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Anomalous effect of Cu2O and CuO deposit on the porosity of a macroreticular anion exchanger

et al. 2021

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When synthesizing copper compounds containing polymeric adsorbents, it was found that the two copper oxides, Cu2O and CuO, deposited in the skeleton of a strongly basic macroreticular anion exchanger (An) radically diminished the porosity of the obtained composites in relation to the host material. In order to investigate this phenomenon more closely, An/Cu2O and An/CuO (both based on the commercial anion exchanger Amberlite IRA900Cl), containing 8.6 and 8.2 wt% Cu, respectively, were subjected to scrutiny. The porous characteristics of the thermally dried and freeze-dried samples were determined using the N2 adsorption–desorption method and mercury intrusion porosimetry. The thermally dried samples lost their porosity and increased their bulk density in relation to the pure resin indicated a significant reduction in their volume. It was found that during drying, the grains shrank as much as the pores collapsed. The decay of the porous structure resulted from the surface morphology of the Cu2O and CuO particles and their tendency to agglomerate. Both freeze-dried samples retained the porous characteristics typical for macroporous anion exchangers. In contrast to the most popular hybrid ion exchangers containing hydrated polyvalent metal oxides (such FeOOH), An/Cu2O and An/CuO showed markedly strong volume contraction effect in relation to moisture content. Graphical abstract

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Effect of the kind of cupric compound deposit on thermal decomposition of anion exchangers

Cited by 7 publications

References 33 publications

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

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

The influence of CuxS particles on the thermal decomposition of anion exchangers

Anomalous effect of Cu2O and CuO deposit on the porosity of a macroreticular anion exchanger

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