182
S. Majidi et al.
Regarding the exclusive and attractive features of the h-BN, such as high strength
and chemically inert, conductivity, and thermal stability, it is a promising 2D nanomaterial in membrane technology [96–98]. The performance of BN laminates for
adsorptive separation of oils, organic solvents, and water was studied by Lei et al.
[3]. They performed a dynamic templating method to obtain the layered structure
of BN. The obtained BN with a remarkable total surface area (1427 m
2 /g) and pore
volume demonstrated the possibility of the BN nanosheet in membrane-based applications. Very recently, nanostructural h-BN with the excellent surface area has been
confirmed to be an original and appealing sorbent material for efficient elimination
of organic pollutants from water [99, 100]. Actually, this is generally due to the
eminent polarity of B–N bonds, lightweight, thermal stability, exceptional chemical,
and ultrahigh surface area of h-BN, which suggests great adsorption performance
for varied organic pollutants [101, 102].
On the other hand, GO has a surface area of around 2630 m
2 /g [103], which is
higher than that of h-BN, and the hydrophobicity of the un-oxidized region of the GO
carbon basal plane may offer high adsorption capability towards organic foulants.
In addition to the high surface area, the GO membrane surface has a water contact
angle of less than 20° [104] and thus is much more hydrophilic than h-BN whose
contact angle values reported in experiments are in the range of 40
z –55
z [105]. Such
great hydrophilicity of the GO membrane causes reduced interactions between the
membrane surface and foulants, which results in the decrement of the membrane
fouling tendency [104, 106].
Besides the nanostructural similarity of h-BN to the graphene-based materials,
the functionalization of h-BN materials can be discovered. Unlike the functionalization of graphene-based materials, which can refer to many organic chemicals,
the functionalization of h-BN is not curreent with chemically active sites in organic
chemistry [107]. Functionalization of h-BN nanosheets is essential to avoid them
from the robust propensity to aggregation and to modify their interfacial properties
and dispersity in solvents and polymer composites [108].
6 New Fabrication Methods
6.1 Physical Vapor Deposition
In addition to synthesis methods mentioned above, 2D substances have also been
exhibited to nucleate and rise crystalline, highly consecutive films through physical
vapor deposition (PVD) methods. In this method, the plasma produced inside a high
vacuum chamber can display ion and electron energies in the order of 1–100 eV.
The metastable and complicated structures, like 2D substance planes, were created
by these processes with controlling the rate and concentration of species inside the
plasma [109]. In sputtering, a thin film on a wafer facing the target is prepared by
bombarding the solid target of the chosen film material with energetic particles. To
S. Majidi et al.
Regarding the exclusive and attractive features of the h-BN, such as high strength
and chemically inert, conductivity, and thermal stability, it is a promising 2D nanomaterial in membrane technology [96–98]. The performance of BN laminates for
adsorptive separation of oils, organic solvents, and water was studied by Lei et al.
[3]. They performed a dynamic templating method to obtain the layered structure
of BN. The obtained BN with a remarkable total surface area (1427 m
2 /g) and pore
volume demonstrated the possibility of the BN nanosheet in membrane-based applications. Very recently, nanostructural h-BN with the excellent surface area has been
confirmed to be an original and appealing sorbent material for efficient elimination
of organic pollutants from water [99, 100]. Actually, this is generally due to the
eminent polarity of B–N bonds, lightweight, thermal stability, exceptional chemical,
and ultrahigh surface area of h-BN, which suggests great adsorption performance
for varied organic pollutants [101, 102].
On the other hand, GO has a surface area of around 2630 m
2 /g [103], which is
higher than that of h-BN, and the hydrophobicity of the un-oxidized region of the GO
carbon basal plane may offer high adsorption capability towards organic foulants.
In addition to the high surface area, the GO membrane surface has a water contact
angle of less than 20° [104] and thus is much more hydrophilic than h-BN whose
contact angle values reported in experiments are in the range of 40
z –55
z [105]. Such
great hydrophilicity of the GO membrane causes reduced interactions between the
membrane surface and foulants, which results in the decrement of the membrane
fouling tendency [104, 106].
Besides the nanostructural similarity of h-BN to the graphene-based materials,
the functionalization of h-BN materials can be discovered. Unlike the functionalization of graphene-based materials, which can refer to many organic chemicals,
the functionalization of h-BN is not curreent with chemically active sites in organic
chemistry [107]. Functionalization of h-BN nanosheets is essential to avoid them
from the robust propensity to aggregation and to modify their interfacial properties
and dispersity in solvents and polymer composites [108].
6 New Fabrication Methods
6.1 Physical Vapor Deposition
In addition to synthesis methods mentioned above, 2D substances have also been
exhibited to nucleate and rise crystalline, highly consecutive films through physical
vapor deposition (PVD) methods. In this method, the plasma produced inside a high
vacuum chamber can display ion and electron energies in the order of 1–100 eV.
The metastable and complicated structures, like 2D substance planes, were created
by these processes with controlling the rate and concentration of species inside the
plasma [109]. In sputtering, a thin film on a wafer facing the target is prepared by
bombarding the solid target of the chosen film material with energetic particles. To