(21f) Magnetic Carbon Nanocomposites: Synthesis and Environmental Remediation

A synergistic process to recycle polystyrene (PS)/Ni@NiO polymer nanocomposites (PNCs) and to fabricate magnetic core@shell Ni@C nanoparticles is introduced. Different pyrolysis pathways of the PNCs have been suggested basing on the analysis of both gas and liquid pyrolysis products from gas chromatography/mass spectrometry (GC/MS). The pyrolysis pathway follows radical generation, recombination and hydrogenation of the PNCs, which generate more saturated structures. However, pure PS undergoes a radical generation and β-scission to form more unsaturated structures. The coke formed during the PS pyrolysis was used as a carbon resource to in-situ synthesize a graphite shell surrounding Ni nanoparticle surface. This Ni@C nanoparticle shows a significantly larger specific area (236.68 m²/g) as compared to bare Ni@NiO nanoparticles (119.62 m²/g) and can be stabilized in 1 M HCl for hours. A large saturated magnetization was also observed in the Ni@C nanoparticles. All these characters make it very useful in environmental remediation applications, with the advantages of higher adsorption capacity and easy magnetic separation process. The application of magnetic carbon nanocomposites in the environmental remediation is addressed as well with the detailed examples in Cr(VI) and As(III) removal from polluted water.

Reference:

Comprehensive and Sustainable Recycling of Polymer Nanocomposites, Journal of Materials Chemistry, 21, 16239-16246 (2011) Doi: 10.1039/C1JM13044G