Poly(vinylidene fluoride) (PVDF) membranes are indispensable for water treatment but suffer from intrinsic hydrophobicity-driven fouling and poor wettability. This study presents a catalyst-free, two-complementary membrane-functionalization strategy based on ammonia-plasma-treated carbon nanohorns (CNHs) and post-grafted sulfonic/zwitterionic groups to create durable, charge-tunable membrane interfaces. Membranes were fabricated using the sustainable solvent triethyl phosphate (TEP) via phase inversion. CNHs provide metal-free carbon scaffolding with superior biocompatibility compared to CNT/graphene alternatives, while post-grafted sulfonic groups enhance surface hydration and electrostatic repulsion of foulants. Comprehensive characterization (XPS, ATR-FTIR, Raman, TEM, contact angles, zeta potential) confirms successful covalent immobilization and synergistic surface chemistry. Membrane fouling experiments with humic acid (100 mg L−1, 6 h cross-flow) reveal water permeability increases of + 33.0% (CNHs) and + 48.5% (sulfonated), reaching 2268 L m−2 h−1 bar−1, a 94% enhancement over pristine PVDF. Humic acid rejection reached ∼85%, with flux recovery ratios of ∼89% after simple cleaning, outperforming many reported benchmarks for CNT/GO-modified PVDF. Hansen Solubility Parameter modeling and predictive bioaccumulation screening (log BAF, BCF, Kow) suggest a comparatively low bioaccumulation potential for the selected modification agents and confirm reduced membrane–foulant affinity. This work establishes a practical pathway toward sustainable, high-flux, metal-free PVDF membranes for reliable water treatment, combining performance enhancement with environmental safety.
Toward more sustainable-solvent-processed PVDF/carbon nanohorn membranes for efficient separation
Di Luca, Giuseppe;Galiano, Francesco;Figoli, Alberto;Gabriele, Bartolo;Kujawski, Wojciech;
2026-01-01
Abstract
Poly(vinylidene fluoride) (PVDF) membranes are indispensable for water treatment but suffer from intrinsic hydrophobicity-driven fouling and poor wettability. This study presents a catalyst-free, two-complementary membrane-functionalization strategy based on ammonia-plasma-treated carbon nanohorns (CNHs) and post-grafted sulfonic/zwitterionic groups to create durable, charge-tunable membrane interfaces. Membranes were fabricated using the sustainable solvent triethyl phosphate (TEP) via phase inversion. CNHs provide metal-free carbon scaffolding with superior biocompatibility compared to CNT/graphene alternatives, while post-grafted sulfonic groups enhance surface hydration and electrostatic repulsion of foulants. Comprehensive characterization (XPS, ATR-FTIR, Raman, TEM, contact angles, zeta potential) confirms successful covalent immobilization and synergistic surface chemistry. Membrane fouling experiments with humic acid (100 mg L−1, 6 h cross-flow) reveal water permeability increases of + 33.0% (CNHs) and + 48.5% (sulfonated), reaching 2268 L m−2 h−1 bar−1, a 94% enhancement over pristine PVDF. Humic acid rejection reached ∼85%, with flux recovery ratios of ∼89% after simple cleaning, outperforming many reported benchmarks for CNT/GO-modified PVDF. Hansen Solubility Parameter modeling and predictive bioaccumulation screening (log BAF, BCF, Kow) suggest a comparatively low bioaccumulation potential for the selected modification agents and confirm reduced membrane–foulant affinity. This work establishes a practical pathway toward sustainable, high-flux, metal-free PVDF membranes for reliable water treatment, combining performance enhancement with environmental safety.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
