et al. (2014b) in another work, studied adsorption affinities of graphene oxide
nanoparticles for polar, nonpolar, and substituted aromatic pollutants. Results
indicated that colloidal graphene oxide nanoparticles (GONPs) exhibited strong
adsorption affinities for all the test compounds, with distribution coefficients on
the order of 103–106 L/kg. The adsorption data of GONPs were compared to other
carbon nanoparticles such as CNTs and C 60 nanoparticles, owing to the dispersion of
graphene oxide as single nanoflakes, which maximized the surface area of adsorption, whereas CNT/C 60 are prone to aggregation. For a given compound GONPs and
CNTs often exhibit different adsorption affinities, which is attributable to the
differences in both the morphology and surface chemistry between the two
nanomaterials. Particularly, the high surface O-content of GONPs (e.g., hydroxy
and carboxylic) enables strong H-bonding and Lewis acid–base interactions with
hydroxyl- and amino-substituted aromatics.
Huang et al. (2018) prepared reduced graphene oxide (RGO)-hybridized polymeric high-internal phase emulsions (RGO/polyHIPEs) with an open-cell structure
using 2-ethylhexyl acrylate (EHA) and ethylene glycol dimethacrylate (EGDMA) as
the monomer and the cross-linker, respectively. They used resultant
RGO/polyHIPEs as sorbent for removal of polycyclic aromatic hydrocarbons
(PAHs). In order to mimic the multifarious PAHs in environmental samples, the
PAH-mixed standards including naphthalene (Nap), fluorene (Flu), phenanthrene
(Phe), anthracene (Ant), fluoranthene (Fla), pyrene (Pyr), benz[a]anthracene (BaA),
chrysene (Chr), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a]
pyrene (BaP), dibenz[a,h]anthracene (DahA), and benzo-[g,h,i]perylene (BghiP)
were used in the adsorption experiments. PAH standards, including naphthalene
(Nap), fluorene (Flu), phenanthrene (Phe), anthracene (Ant), fluoranthene (Fla),
pyrene (Pyr), benz[a]anthracene (BaA), chrysene (Chr), benzo[b]fluoranthene
(BbF), benzo[k]fluoranthene (BkF), benzo[a]pyrene (BaP), dibenz[a,h]anthracene
(DahA), and benzo-[g,h,i]perylene (BghiP). Results indicated that the saturated
adsorption capacity is 47.5 mg/g and has good cycling stability to PAHs up to
10 adsorptionÀdesorption cycles. PAH residues in water samples after being treated
with RGO/polyHIPEs are lower than the limit set by the European Food Safety
Authority for drinking water. Moreover, Huang et al. (2019) compared adsorption
properties of magnetic graphene oxide (MGO), magnetic chemically reduced
graphene (MCRG), and magnetic annealing-reduced graphene (MARG) for adsorption of phenanthrene. In comparison, results revealed that MCRG had highest
adsorption properties for the removal of PAH from water. The π–π interaction was
the predominant adsorption mechanism of MCRG. The effects of environmental
factors on the adsorption–desorption properties of phenanthrene pH, heavy metal
ions, and natural organic matter were also investigated and were little affected by pH
and coexisting Cd(II) and As(V). Humic acids considerably decreased the adsorption
of phenanthrene by MCRG.
9 Application of Carbon-Based Nanomaterials for Removal of Hydrocarbons
217
nanoparticles for polar, nonpolar, and substituted aromatic pollutants. Results
indicated that colloidal graphene oxide nanoparticles (GONPs) exhibited strong
adsorption affinities for all the test compounds, with distribution coefficients on
the order of 103–106 L/kg. The adsorption data of GONPs were compared to other
carbon nanoparticles such as CNTs and C 60 nanoparticles, owing to the dispersion of
graphene oxide as single nanoflakes, which maximized the surface area of adsorption, whereas CNT/C 60 are prone to aggregation. For a given compound GONPs and
CNTs often exhibit different adsorption affinities, which is attributable to the
differences in both the morphology and surface chemistry between the two
nanomaterials. Particularly, the high surface O-content of GONPs (e.g., hydroxy
and carboxylic) enables strong H-bonding and Lewis acid–base interactions with
hydroxyl- and amino-substituted aromatics.
Huang et al. (2018) prepared reduced graphene oxide (RGO)-hybridized polymeric high-internal phase emulsions (RGO/polyHIPEs) with an open-cell structure
using 2-ethylhexyl acrylate (EHA) and ethylene glycol dimethacrylate (EGDMA) as
the monomer and the cross-linker, respectively. They used resultant
RGO/polyHIPEs as sorbent for removal of polycyclic aromatic hydrocarbons
(PAHs). In order to mimic the multifarious PAHs in environmental samples, the
PAH-mixed standards including naphthalene (Nap), fluorene (Flu), phenanthrene
(Phe), anthracene (Ant), fluoranthene (Fla), pyrene (Pyr), benz[a]anthracene (BaA),
chrysene (Chr), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a]
pyrene (BaP), dibenz[a,h]anthracene (DahA), and benzo-[g,h,i]perylene (BghiP)
were used in the adsorption experiments. PAH standards, including naphthalene
(Nap), fluorene (Flu), phenanthrene (Phe), anthracene (Ant), fluoranthene (Fla),
pyrene (Pyr), benz[a]anthracene (BaA), chrysene (Chr), benzo[b]fluoranthene
(BbF), benzo[k]fluoranthene (BkF), benzo[a]pyrene (BaP), dibenz[a,h]anthracene
(DahA), and benzo-[g,h,i]perylene (BghiP). Results indicated that the saturated
adsorption capacity is 47.5 mg/g and has good cycling stability to PAHs up to
10 adsorptionÀdesorption cycles. PAH residues in water samples after being treated
with RGO/polyHIPEs are lower than the limit set by the European Food Safety
Authority for drinking water. Moreover, Huang et al. (2019) compared adsorption
properties of magnetic graphene oxide (MGO), magnetic chemically reduced
graphene (MCRG), and magnetic annealing-reduced graphene (MARG) for adsorption of phenanthrene. In comparison, results revealed that MCRG had highest
adsorption properties for the removal of PAH from water. The π–π interaction was
the predominant adsorption mechanism of MCRG. The effects of environmental
factors on the adsorption–desorption properties of phenanthrene pH, heavy metal
ions, and natural organic matter were also investigated and were little affected by pH
and coexisting Cd(II) and As(V). Humic acids considerably decreased the adsorption
of phenanthrene by MCRG.
9 Application of Carbon-Based Nanomaterials for Removal of Hydrocarbons
217