The three-dimensional covalent polymer 7 , based on dimeric calix[4]tube macrocycles and 1,4-diethynylbenzene bridges, was synthesized through Sonogashira coupling and investigated as a multifunctional adsorbent for water and gas remediation. This work represents, to the best of our knowledge, the first use of calix[4]tubes as building blocks for porous adsorbents, expanding the family of macrocycle-based covalent materials. The polymer forms a thermally stable, mesoporous aromatic network with a near-neutral surface (ζ = –0.18 ± 3.52 mV), enabling efficient adsorption of cationic, anionic, neutral, and zwitterionic dyes. Adsorption of rhodamine B, methylene blue, eosin, and methyl yellow from (semi)aqueous solutions followed pseudo-second-order kinetics, with faster uptake observed for anionic, cationic, and zwitterionic dyes. Weber–Morris analysis indicated that intraparticle diffusion contributes mainly to the initial stage of adsorption, except for eosin, for which it remains the predominant transport mechanism throughout the explored time range. Adsorption isotherms suggested that the process is governed primarily by weak non-covalent interaction, hydrophobic effects, and shape complementarity rather than dye charge, with maximum adsorption capacities of 15, 124, 92, and 167 mg g⁻¹ for methylene blue, rhodamine B, eosin, and methyl yellow, respectively. Beyond liquid-phase remediation, polymer 7 exhibited a CO₂ uptake of 94.6 mg g⁻¹ at 25 °C and 1 bar, approaching the performance of benchmark porous adsorbents. These findings establish calix[4]tube-based covalent polymers as a versatile new platform for broad-spectrum water purification and gas capture, opening unexplored opportunities for macrocycle-based functional materials.
A three dimensional calix[4]tube-derived covalent polymer for dye adsorption and CO₂ capture
Pulvirenti, L.;Fiorenza, R.;Condorelli, G. G.;
2026-01-01
Abstract
The three-dimensional covalent polymer 7 , based on dimeric calix[4]tube macrocycles and 1,4-diethynylbenzene bridges, was synthesized through Sonogashira coupling and investigated as a multifunctional adsorbent for water and gas remediation. This work represents, to the best of our knowledge, the first use of calix[4]tubes as building blocks for porous adsorbents, expanding the family of macrocycle-based covalent materials. The polymer forms a thermally stable, mesoporous aromatic network with a near-neutral surface (ζ = –0.18 ± 3.52 mV), enabling efficient adsorption of cationic, anionic, neutral, and zwitterionic dyes. Adsorption of rhodamine B, methylene blue, eosin, and methyl yellow from (semi)aqueous solutions followed pseudo-second-order kinetics, with faster uptake observed for anionic, cationic, and zwitterionic dyes. Weber–Morris analysis indicated that intraparticle diffusion contributes mainly to the initial stage of adsorption, except for eosin, for which it remains the predominant transport mechanism throughout the explored time range. Adsorption isotherms suggested that the process is governed primarily by weak non-covalent interaction, hydrophobic effects, and shape complementarity rather than dye charge, with maximum adsorption capacities of 15, 124, 92, and 167 mg g⁻¹ for methylene blue, rhodamine B, eosin, and methyl yellow, respectively. Beyond liquid-phase remediation, polymer 7 exhibited a CO₂ uptake of 94.6 mg g⁻¹ at 25 °C and 1 bar, approaching the performance of benchmark porous adsorbents. These findings establish calix[4]tube-based covalent polymers as a versatile new platform for broad-spectrum water purification and gas capture, opening unexplored opportunities for macrocycle-based functional materials.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
