Ion Exchangers

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

“…The difference in copper content between the HIXs containing Cu 2 O and the ones containing Cu 0 was due to the different ionic form of the functional groups (hydroxylic vs. ascorbate, molar mass 17 vs. 175). Since anion exchangers show low thermal stability [ 38 , 39 ], all the materials investigated in this study were dried in mild conditions (at 40 °C for 24 h). The test results, grouped according to the structure of the host materials (M, G) and the thermal decomposition medium (air, N 2 ), are presented in successive figures.…”

“…Typically, in the parent resins (M, G) the functional ionogenic groups were surrounded by water molecules, which is referred to as solvation. This phenomenon is due to weak electrostatic interactions and results in the formation of a solvation envelope (a few water molecules thick) around polar functional groups [ 29 , 39 , 40 ]. After Cu 0 was deposited in the anion exchanger’s matrix the configuration near the active groups changed.…”

“…Gel-like anion exchangers contain less cross-linking agent (about 8% DVB) than macroreticular ion exchangers (about 15% DVB) and the fewer cross linkages an anion exchanger contains, the greater are its elasticity and swelling (this is why gel-like anion exchangers swell much more than macroreticular anion exchangers). Swelling and shrinking are reversible processes and are indeed accompanied by uptake/expulsion of water molecules [ 29 , 39 ]. Therefore one could suppose that in the presence of the water repelling agent the gel-like anion exchangers having a more elastic matrix shrank more than the macroreticular ones (the osmotic force and the elastic force act in opposite directions).…”

“…This is in agreement with the FTIR analysis results for the examined materials, indicating that after the reduction of Cu 2 O to Cu 0 the area of the broad peak indicative of adsorbed water at 3350 cm −1 decreased and almost vanished in the case of G/Cu [ 33 ]. 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 ].…”

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

“…The difference in copper content between the HIXs containing Cu 2 O and the ones containing Cu 0 was due to the different ionic form of the functional groups (hydroxylic vs. ascorbate, molar mass 17 vs. 175). Since anion exchangers show low thermal stability [ 38 , 39 ], all the materials investigated in this study were dried in mild conditions (at 40 °C for 24 h). The test results, grouped according to the structure of the host materials (M, G) and the thermal decomposition medium (air, N 2 ), are presented in successive figures.…”

“…Typically, in the parent resins (M, G) the functional ionogenic groups were surrounded by water molecules, which is referred to as solvation. This phenomenon is due to weak electrostatic interactions and results in the formation of a solvation envelope (a few water molecules thick) around polar functional groups [ 29 , 39 , 40 ]. After Cu 0 was deposited in the anion exchanger’s matrix the configuration near the active groups changed.…”

“…Gel-like anion exchangers contain less cross-linking agent (about 8% DVB) than macroreticular ion exchangers (about 15% DVB) and the fewer cross linkages an anion exchanger contains, the greater are its elasticity and swelling (this is why gel-like anion exchangers swell much more than macroreticular anion exchangers). Swelling and shrinking are reversible processes and are indeed accompanied by uptake/expulsion of water molecules [ 29 , 39 ]. Therefore one could suppose that in the presence of the water repelling agent the gel-like anion exchangers having a more elastic matrix shrank more than the macroreticular ones (the osmotic force and the elastic force act in opposite directions).…”

“…This is in agreement with the FTIR analysis results for the examined materials, indicating that after the reduction of Cu 2 O to Cu 0 the area of the broad peak indicative of adsorbed water at 3350 cm −1 decreased and almost vanished in the case of G/Cu [ 33 ]. 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 ].…”

Syntheses of Cation Exchanger With Macroporosity and Investigating Specific Properties

“…The sulfonation temperature 70°C for 6 hours. To avoid deformation of the polymer matrix after sulfonation, the cooled polymer was washed with sulfuric acid, decreasing the concentration successively to 75, 50, 25 and 10% and then washed with distilled water until neutral wash water, then the resulting cation exchanger was dried at 80-90°C in a drying cabinet [10][11][12][13].…”

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

“…The difference in copper content between the HIXs containing Cu 2 O and the ones containing Cu 0 was due to the different ionic form of the functional groups (hydroxylic vs. ascorbate, molar mass 17 vs. 175). Since anion exchangers show low thermal stability [ 38 , 39 ], all the materials investigated in this study were dried in mild conditions (at 40 °C for 24 h). The test results, grouped according to the structure of the host materials (M, G) and the thermal decomposition medium (air, N 2 ), are presented in successive figures.…”

“…Typically, in the parent resins (M, G) the functional ionogenic groups were surrounded by water molecules, which is referred to as solvation. This phenomenon is due to weak electrostatic interactions and results in the formation of a solvation envelope (a few water molecules thick) around polar functional groups [ 29 , 39 , 40 ]. After Cu 0 was deposited in the anion exchanger’s matrix the configuration near the active groups changed.…”

“…Gel-like anion exchangers contain less cross-linking agent (about 8% DVB) than macroreticular ion exchangers (about 15% DVB) and the fewer cross linkages an anion exchanger contains, the greater are its elasticity and swelling (this is why gel-like anion exchangers swell much more than macroreticular anion exchangers). Swelling and shrinking are reversible processes and are indeed accompanied by uptake/expulsion of water molecules [ 29 , 39 ]. Therefore one could suppose that in the presence of the water repelling agent the gel-like anion exchangers having a more elastic matrix shrank more than the macroreticular ones (the osmotic force and the elastic force act in opposite directions).…”

“…This is in agreement with the FTIR analysis results for the examined materials, indicating that after the reduction of Cu 2 O to Cu 0 the area of the broad peak indicative of adsorbed water at 3350 cm −1 decreased and almost vanished in the case of G/Cu [ 33 ]. 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 ].…”

Syntheses of Cation Exchanger With Macroporosity and Investigating Specific Properties

“…The sulfonation temperature 70°C for 6 hours. To avoid deformation of the polymer matrix after sulfonation, the cooled polymer was washed with sulfuric acid, decreasing the concentration successively to 75, 50, 25 and 10% and then washed with distilled water until neutral wash water, then the resulting cation exchanger was dried at 80-90°C in a drying cabinet [10][11][12][13].…”

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

“…The difference in copper content between the HIXs containing Cu 2 O and the ones containing Cu 0 was due to the different ionic form of the functional groups (hydroxylic vs. ascorbate, molar mass 17 vs. 175). Since anion exchangers show low thermal stability [ 38 , 39 ], all the materials investigated in this study were dried in mild conditions (at 40 °C for 24 h). The test results, grouped according to the structure of the host materials (M, G) and the thermal decomposition medium (air, N 2 ), are presented in successive figures.…”

“…Typically, in the parent resins (M, G) the functional ionogenic groups were surrounded by water molecules, which is referred to as solvation. This phenomenon is due to weak electrostatic interactions and results in the formation of a solvation envelope (a few water molecules thick) around polar functional groups [ 29 , 39 , 40 ]. After Cu 0 was deposited in the anion exchanger’s matrix the configuration near the active groups changed.…”

“…Gel-like anion exchangers contain less cross-linking agent (about 8% DVB) than macroreticular ion exchangers (about 15% DVB) and the fewer cross linkages an anion exchanger contains, the greater are its elasticity and swelling (this is why gel-like anion exchangers swell much more than macroreticular anion exchangers). Swelling and shrinking are reversible processes and are indeed accompanied by uptake/expulsion of water molecules [ 29 , 39 ]. Therefore one could suppose that in the presence of the water repelling agent the gel-like anion exchangers having a more elastic matrix shrank more than the macroreticular ones (the osmotic force and the elastic force act in opposite directions).…”

“…This is in agreement with the FTIR analysis results for the examined materials, indicating that after the reduction of Cu 2 O to Cu 0 the area of the broad peak indicative of adsorbed water at 3350 cm −1 decreased and almost vanished in the case of G/Cu [ 33 ]. 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 ].…”

Syntheses of Cation Exchanger With Macroporosity and Investigating Specific Properties

“…The sulfonation temperature 70°C for 6 hours. To avoid deformation of the polymer matrix after sulfonation, the cooled polymer was washed with sulfuric acid, decreasing the concentration successively to 75, 50, 25 and 10% and then washed with distilled water until neutral wash water, then the resulting cation exchanger was dried at 80-90°C in a drying cabinet [10][11][12][13].…”