bagasse showed good oilsorption and recovery, indicating that these natural sorbents
could be a viable alternative choice instead of synthetic products.
In conclusion, natural sorbents are biodegradable, low cost, and can be burned as
fuels. In summary, natural oilsorbents have some deficits like poor recyclability and
adequate floatability, while, there is growing regard for use of natural sorbents
because of their eco-friendly behavior.
12.5.2 Synthetic Sorbents
Nowadays, fabrication of superoleophilic and superhydrophobic surfaces as
oilsorbents has attracted a lot of attention. These porous materials have a significant
oilsorption capacity, high floatability, low surface energy, and good reusability.
They have some shortcomings like expensive, complex and time-cost fabrication
process, and environmental incompatibility. In the following, the performance of
some types of synthetic sorbents and their limitations are explained.
Nanofibers
Nanofibers are hydrophobic–oleophilic surfaces, which are able to trap the spilled oil
inside of their porous structures and transfer liquid oil to a semi-solid structure.
Nowadays, consideration has been given to the development and use of nanofibers
based on their good hydrophobicity–oleophilicity, physical and mechanical properties, low surface energy, good buoyancy, high surface area, small pore size, and high
uptake capacity. Melt bowling, force spinning, electrospinning, and bicomponent
spinning are the common methods to produce polymeric nanofibers. Figure 12.14
shows the melt-blowing process device, the bicomponent spinning machine, and the
centrifugal spinning device, which were used in some researches.
Electrospinning is used widely as an efficient and typical procedure for fabricating polymeric nanofibers with micro and nanoscales using various materials. An
ordinary electrospinning process is illustrated in Fig. 12.15. Liquid polymer transfers
to a needle by a syringe pump. The polymer globule surface changes to the Taylor
Cone due to high voltage of needle. A spurt of melt polymer, which errupts from the
needle, moves through the air and forms the polymer fibers. The safety of operators
of the electrospinning apparatus is the most important concern. Inhalation of
nanofibers, high voltage, and evaporation of solvent are disturbing issues.
Surface morphology, porosity, diameter, voids among the fibers and surface
tension influence the behavior and oilsorption capacities of the nanofibers. The
rough surface of the fibers can enhance the oiladsorption. Porous nanofibers are
capable of adsorbing oil due to specific surface area. On the other hand, the high
porosity and small diameter of the fibers increase the capacity of oilsorption. As the
12 Remediation of Pollution by Oil Spills
415
could be a viable alternative choice instead of synthetic products.
In conclusion, natural sorbents are biodegradable, low cost, and can be burned as
fuels. In summary, natural oilsorbents have some deficits like poor recyclability and
adequate floatability, while, there is growing regard for use of natural sorbents
because of their eco-friendly behavior.
12.5.2 Synthetic Sorbents
Nowadays, fabrication of superoleophilic and superhydrophobic surfaces as
oilsorbents has attracted a lot of attention. These porous materials have a significant
oilsorption capacity, high floatability, low surface energy, and good reusability.
They have some shortcomings like expensive, complex and time-cost fabrication
process, and environmental incompatibility. In the following, the performance of
some types of synthetic sorbents and their limitations are explained.
Nanofibers
Nanofibers are hydrophobic–oleophilic surfaces, which are able to trap the spilled oil
inside of their porous structures and transfer liquid oil to a semi-solid structure.
Nowadays, consideration has been given to the development and use of nanofibers
based on their good hydrophobicity–oleophilicity, physical and mechanical properties, low surface energy, good buoyancy, high surface area, small pore size, and high
uptake capacity. Melt bowling, force spinning, electrospinning, and bicomponent
spinning are the common methods to produce polymeric nanofibers. Figure 12.14
shows the melt-blowing process device, the bicomponent spinning machine, and the
centrifugal spinning device, which were used in some researches.
Electrospinning is used widely as an efficient and typical procedure for fabricating polymeric nanofibers with micro and nanoscales using various materials. An
ordinary electrospinning process is illustrated in Fig. 12.15. Liquid polymer transfers
to a needle by a syringe pump. The polymer globule surface changes to the Taylor
Cone due to high voltage of needle. A spurt of melt polymer, which errupts from the
needle, moves through the air and forms the polymer fibers. The safety of operators
of the electrospinning apparatus is the most important concern. Inhalation of
nanofibers, high voltage, and evaporation of solvent are disturbing issues.
Surface morphology, porosity, diameter, voids among the fibers and surface
tension influence the behavior and oilsorption capacities of the nanofibers. The
rough surface of the fibers can enhance the oiladsorption. Porous nanofibers are
capable of adsorbing oil due to specific surface area. On the other hand, the high
porosity and small diameter of the fibers increase the capacity of oilsorption. As the
12 Remediation of Pollution by Oil Spills
415