1. Mixed nanomaterials: In this type, the arrangement of atoms can be either
ordered or random. Ordered arrangement corresponds to the positioning of A
and B atom.
2. Core-shell nanomaterials: In this form of ordering, NMs composed of two
different types of atoms in which one type of atom surrounds another type of
atom forming a shell kind of structure. There’s one more subcategory of coreshell NMs i.e., multishell or onion-like NPs. The arrangement is in the form of AB-C in the case of three different atoms and A-B-A form for two different atoms
in an alternating form.
3. Layered nanomaterials: This type of arrangement is also known as dumbbell-like
NPs. This form comprises of two different NPs having a mutual interface that
inclines to lessen the bonds among the atoms.
Apart from these types, there are other types of NMs having different
compositions which were synthesized after looking at the increasing need for
multi-functional NMs i.e., multicore shell structure in which core is in the shape of
onion-like or dumbbell-like (Shi et al. 2006; Llamosa Pérez et al. 2013; Benelmekki
et al. 2014, 2015; Benelmekki and Sowwan 2015).
2.3.3 NP Uniformity and Agglomeration
According to the properties of the NPs, NPs can be formed as a suspension/colloids,
solid, dispersed aerosol, or in agglomerated form. Agglomerated NPs synthesized
due to the van der Waals forces and Brownian motion. Agglomeration caused by
Brownian motion is known as coagulation. Many processes help in the removal of
agglomeration of NPs, one of the ways to avoid the agglomeration is by coating the
NPs by another organic or inorganic material. In the case of magnetic NPs also,
agglomeration of NPs is documented unless NPs are coated with any non–magnetic
substance.
2.3.4 NP Characterization
After the fabrication of NPs, it is important to characterize the particles to understand
the NPs in detail like their structure, composition, uniformity, charge, etc. To
understand these properties of NPs, many techniques can be utilized for their
characterization. The main techniques of characterizations are transmission electron
microscopy (TEM), scanning TEM (STEM), scanning electron microscope (SEM),
electron energy loss spectroscopy (EELS), X-ray powder diffraction (XRD) and
X-ray photoelectron ppectroscopy (XPS) (Mourdikoudis et al. 2018).
2 Nanomaterials; Applications; Implications and Management
29
ordered or random. Ordered arrangement corresponds to the positioning of A
and B atom.
2. Core-shell nanomaterials: In this form of ordering, NMs composed of two
different types of atoms in which one type of atom surrounds another type of
atom forming a shell kind of structure. There’s one more subcategory of coreshell NMs i.e., multishell or onion-like NPs. The arrangement is in the form of AB-C in the case of three different atoms and A-B-A form for two different atoms
in an alternating form.
3. Layered nanomaterials: This type of arrangement is also known as dumbbell-like
NPs. This form comprises of two different NPs having a mutual interface that
inclines to lessen the bonds among the atoms.
Apart from these types, there are other types of NMs having different
compositions which were synthesized after looking at the increasing need for
multi-functional NMs i.e., multicore shell structure in which core is in the shape of
onion-like or dumbbell-like (Shi et al. 2006; Llamosa Pérez et al. 2013; Benelmekki
et al. 2014, 2015; Benelmekki and Sowwan 2015).
2.3.3 NP Uniformity and Agglomeration
According to the properties of the NPs, NPs can be formed as a suspension/colloids,
solid, dispersed aerosol, or in agglomerated form. Agglomerated NPs synthesized
due to the van der Waals forces and Brownian motion. Agglomeration caused by
Brownian motion is known as coagulation. Many processes help in the removal of
agglomeration of NPs, one of the ways to avoid the agglomeration is by coating the
NPs by another organic or inorganic material. In the case of magnetic NPs also,
agglomeration of NPs is documented unless NPs are coated with any non–magnetic
substance.
2.3.4 NP Characterization
After the fabrication of NPs, it is important to characterize the particles to understand
the NPs in detail like their structure, composition, uniformity, charge, etc. To
understand these properties of NPs, many techniques can be utilized for their
characterization. The main techniques of characterizations are transmission electron
microscopy (TEM), scanning TEM (STEM), scanning electron microscope (SEM),
electron energy loss spectroscopy (EELS), X-ray powder diffraction (XRD) and
X-ray photoelectron ppectroscopy (XPS) (Mourdikoudis et al. 2018).
2 Nanomaterials; Applications; Implications and Management
29