PVDF/Clay Spheres Obtained through Phase Inversion for Cu Ion Removal.

Area of Science:

• Materials Science
• Environmental Science
• Chemical Engineering

Background:

• Poly (vinylidene fluoride) (PVDF) is a versatile polymer with potential applications in separation technologies.
• Clay composites offer enhanced properties for adsorption and purification processes.
• Copper contamination in beverages is a concern for public health and regulatory compliance.

Purpose of the Study:

• To synthesize and characterize poly (vinylidene fluoride)/clay spheres for copper removal.
• To evaluate the efficiency of these composite spheres in removing copper from aqueous, ethanolic, and cachaça solutions.
• To assess the performance of the material against Brazilian environmental regulations.

Main Methods:

• Spheres of poly (vinylidene fluoride)/clay were synthesized using the phase inversion method.
• Material characterization included scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermal analysis.
• Batch and column adsorption tests were performed using copper-spiked solutions and commercial cachaça.

Main Results:

• SEM analysis revealed that clay inclusion modifies the porous structure of PVDF spheres, reducing a low-porosity intermediate layer and widening surface pores.
• The composite with 30% clay content demonstrated the highest copper removal efficiency: 32.4% in aqueous and 46.8% in ethanolic media.
• Column adsorption tests showed removal efficiencies exceeding 50%, aligning with Brazilian legislative standards for copper levels in beverages.

Conclusions:

• Poly (vinylidene fluoride)/clay composite spheres are effective for copper removal from various media.
• The optimized composite material meets regulatory requirements for copper content in beverages.
• The adsorption behavior of copper onto the composite spheres is best described by the BET model.