Graphene Oxide and Reduced Graphene Oxide as Nanofillers …
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provides an effective method to develop freestanding, lightweight, and strong polyimide–GO composite materials with low dielectric constants and shows promise for
a wide range of applications.
Researchers have reported an in situ polymerization step that was combined
with chemical grafting modification for fabricating poly(vinyl alcohol)-grafted
GO/poly(vinyl alcohol) nanocomposites [81]. The poly(vinyl alcohol)-g-GO sheets
displayed great dispersion and compatibility with the poly(vinyl alcohol) matrix and
also created strong interfacial interactions with the poly(vinyl alcohol) chains of the
matrix [68].
2.3 Melt Processing
Melt processing is the most eco-friendly and economical method [53] and is appropriate for mass production of GO composites for industrial applications [82], but
the high viscosity of polymer melts and the high temperature used in this process
always leads to GO flocculation [83]. Besides, the high shear forces used in melt
compounding can often cause the breakage of the filler materials such as the
graphene-based nanosheets and CNTs [84]. However, these preparation methods
are less or more restricted in applications, they demonstrate their sole advantages to
fabricate polymer–GO composite materials [69].
In melt processing, no solvent is needed due to utilizing both high-temperature
melting and high-shear forces to mix the filler and matrix materials and combining
the graphene or modified graphene with the polymer matrix is done in the molten
state [36]. In this procedure, the polymer and graphene/GO/rGO are directly mixed
in a twin-screw extruder, and then the parameters of the extruder screw, such as the
screw speed, blending time, and temperature are regulated [68].
In general, most of the polymer–GO nanocomposites are prepared by using
polypropylene (PP), polyurethane, poly (ethylene terephthalate), poly (ether ketone),
Polystyrene (PS), styrene–ethylene/butylene–styrene triblock copolymers [45, 85–
87]. Melt blending is a promising method for the preparation of commercial
nanocomposite products because of its processing without using organic solvents
[68].
2.4 Pickering Emulsions
Pickering emulsion is the preparation of polymer nanocomposites via the selfassembly of nanoparticles at liquid–liquid interface [88]. It is a promising approach
for the design and preparation of well-defined nanostructured materials [89–91].
Self-assembly of the materials at the liquid–liquid interface is thermodynamically
promising because of the decrease in the interfacial energy of the system upon the
formation of a new interface between the liquid and particle phases instead of the
117
provides an effective method to develop freestanding, lightweight, and strong polyimide–GO composite materials with low dielectric constants and shows promise for
a wide range of applications.
Researchers have reported an in situ polymerization step that was combined
with chemical grafting modification for fabricating poly(vinyl alcohol)-grafted
GO/poly(vinyl alcohol) nanocomposites [81]. The poly(vinyl alcohol)-g-GO sheets
displayed great dispersion and compatibility with the poly(vinyl alcohol) matrix and
also created strong interfacial interactions with the poly(vinyl alcohol) chains of the
matrix [68].
2.3 Melt Processing
Melt processing is the most eco-friendly and economical method [53] and is appropriate for mass production of GO composites for industrial applications [82], but
the high viscosity of polymer melts and the high temperature used in this process
always leads to GO flocculation [83]. Besides, the high shear forces used in melt
compounding can often cause the breakage of the filler materials such as the
graphene-based nanosheets and CNTs [84]. However, these preparation methods
are less or more restricted in applications, they demonstrate their sole advantages to
fabricate polymer–GO composite materials [69].
In melt processing, no solvent is needed due to utilizing both high-temperature
melting and high-shear forces to mix the filler and matrix materials and combining
the graphene or modified graphene with the polymer matrix is done in the molten
state [36]. In this procedure, the polymer and graphene/GO/rGO are directly mixed
in a twin-screw extruder, and then the parameters of the extruder screw, such as the
screw speed, blending time, and temperature are regulated [68].
In general, most of the polymer–GO nanocomposites are prepared by using
polypropylene (PP), polyurethane, poly (ethylene terephthalate), poly (ether ketone),
Polystyrene (PS), styrene–ethylene/butylene–styrene triblock copolymers [45, 85–
87]. Melt blending is a promising method for the preparation of commercial
nanocomposite products because of its processing without using organic solvents
[68].
2.4 Pickering Emulsions
Pickering emulsion is the preparation of polymer nanocomposites via the selfassembly of nanoparticles at liquid–liquid interface [88]. It is a promising approach
for the design and preparation of well-defined nanostructured materials [89–91].
Self-assembly of the materials at the liquid–liquid interface is thermodynamically
promising because of the decrease in the interfacial energy of the system upon the
formation of a new interface between the liquid and particle phases instead of the