Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_5932_Библиотеки_им_академика_М_И_Перельмана
.pdf
6 Carbon-Based Nanocarriers for Drug Delivery
(a)
(b)
FIGURE 1.1 (a) The Chiral Vector C and Chiral Angle θ Dening a Nanotube on a Graphene
Sheet [2], (b) Classication of SWCNTs Based on the Chirality. [Reprinted with permission
from N. Grobert (2007)] [59].
structure. As shown in Figure 1.1 [53,59], The SWCNTs are further divided into
three different types based on how they are wrapped into cylindrical congurations,
namely, armchair, chiral, and zigzag. Apair of indices (n, m) used to specify the conguration of an SWCNT are used to characterize the chiral vectors and their direct
inuence on the electrical properties of nanotubes. The graphene honeycomb crystal
structure’s number of unit vectors across two orientations is dened by the integers n
and m. According to popular belief, nanotubes are zigzag nanotubes if m=0, armchair nanotubes if n=m, and chiral in other states [53].
The diameter of MWCNTs, which varies based on the number of tubes rolled
together, ranges from 2 to 50 nm. MWCNTs are composed of multilayered
graphene nanosheets that have been wrapped around one another. In contrast to
SWCNTs, MWCNTs may be produced without a catalyst and have both a complex
structure and a pure form. Additionally, the MWCNTs are challenging to twist
7Fundamentals of Carbon-Based Nanomaterials
and frequently take the appearance of granules or a black, uffy powder [54].
The interlayerspacingin these tubes is roughly 0.34 nm [11,53]. The Russian
Doll and Parchment models are two important structural models for MWCNTs.
The Russian Doll model is present when a carbon nanotube has other nanotubes
beneath it, and the outer nanotube is thicker than the inner one. The Parchment
model, in contrast, describes a single graphene sheet being wrapped around itself
several times to resemble a scroll of paper. MWCNTs and SWCNTs have comparable properties. Due to their multilayer structure, MWCNTs exhibit strong
tensile strength properties that SWCNTs lack while protecting the inner carbon
nanotubes from chemical reactions with exterior pollutants [53,60]. Additionally,
there is another variety of CNTs that resembles SWCNTs in terms of structure.
These nanotubes, often referred to as dual or double-walled carbon nanotubes, are
composed of two concentric sheets that enclose an inner cylindrical tube inside an
outer tube (CNTs) [61].
CNTs have been widely used as drug delivery in pharmaceutical and medicinal
applications since the turn of the 21st century. They are distinguished from bulk
equivalents of the same composition (in microscale) by their very tiny size, high
reactivity, needle-like shape, substantial strength, adaptive interaction with the cargo,
greater drug loading efciency, remarkable electrical and optical characteristics,
good stability, biocompatibility, and capacity to deliver therapeutic molecules at particular or targeted locations. They also stand out owing to their high surface area
to mass ratio and capability to deliver therapeutic molecules at specic or targeted
sites [56,62]. Furthermore, because CNTs immediately penetrate cells and keep
drug molecules intact throughout delivery without metabolizing them, they have
been found to be an efcient drug delivery vehicle. Several therapeutic compounds,
such as drugs, antibodies, nucleic acids, proteins, and enzymes, can be conjugated
to or absorbed by CNTs, such as SWCNT and MWCNT. CNTs display toxicity and
biodegradability-related problems, which further restricts their use for biomedical
applications even if these traits are associated with highly desirable characteristics.
However, despite several limitations, CNTs continue to exhibit excellent performance in the eld of health care, notably in the elds of drug delivery, gene therapy,
bioimaging, and biosensors. [11,62].
Lack of solubility, dispersibility, biodistribution, bioactivity, biodegradability,
and toxicity are the main obstacles to the use of CNTs in biomedical domains. The
hydrophobic structure, van der Waals interactions, the length of the CNTs, as well as
the nonuniformity in their surface properties are mostly responsible for these deciencies. However, these difculties can be solved by functionalizing CNTs with
hydrophilic and more biocompatible functional components like biopolymers and
targeting ligands. Numerous biological applications, including biosensing, disease
diagnosis, and therapy, have beneted greatly from functionalized CNTs [63]. They
provide biomedical imaging, enable the detection of diverse biological targets, and
deliver therapeutic materials, such as drugs and genes [64,65]. Their inherent spectroscopic characteristics, including photoluminescence and Raman scattering, can
offer useful tools for monitoring, identifying, and imaging disorders. They can also
aid in tracking the state of in-vivo treatment, pharmacodynamic behavior, and drug
delivery effectiveness.
8 Carbon-Based Nanocarriers for Drug Delivery
1.2.2.2 Graphene nanoribbons
Graphene nanoribbons (GNRs) are thin strips of graphene made of alternating hexagonal carbon cells that can be up to 50 nm broad and dozens of micrometers long
based on the production process [66]. To examine the edge and nanoscale effects of
graphene, Fuhita et al. (1996) computationally interpreted GNRs in 1996 [67,68].
GNRs are notably different compared to the more well-known 2-D graphene
nanosheets owing to their quasi-1-Dstructure [69]. GNRs are very precise tools that
hold promise for nanoelectronic components, incredibly sensitive mechanical and
chemical sensors, etc. [70–72]. They are virtually perfect nanowires or nanotags.
Additionally, the synthesis technique has a substantial impact on the structure and
physical characteristics of GNRs. GNRs exhibit a 1-D morphology with a substantial
class of conjugated polymers, whose performance parameters are determined by the
conditions of synthesis and the technique used to form lms [73,74]. Since the structure, width, and orientation of the crystal’s edge are extremely important to the electrical and optical characteristics of GNRs, their structural perfection is a key issue
[66]. The “armchair” or AGNRs, “zigzag” or GNRs with zigzag edges (ZGNRs), and
“cove” edge congurations are the three most often researched varieties of GNRs
edge structures [75]. The most typical GNRs have zigzag and armchair-style edges.
Although ZGNRs are anticipated to have lower band gaps with conned magnetic
edge states and enormous prospective for spintronic applications, AGNRs are distinguished by a large band gap that modulates with theirwidth [76–78]. Cove-type
GNRs may have their edges altered to smoothly decrease energy band gaps, albeit at
the cost of conjugation breakdowns and higher morphological spreading [79].
The sp2 hybridized carbon’s interaction with other molecules causes GNRs to
assemble readily in both their solid and liquid forms. The easiest way to reduce such
“π-π” interaction in the solution is to include different functional groups. As a result,
the additional functional groups might lessen π-π interaction while maintaining
the aromatic structure. For this goal, three techniques have been described so far:
introducing alkyl heteroatoms [80], functionalizing with polymers of high molecular
weight [81], and introducing bulky3-D heteroatoms to the surface of GNRs [82].
The term “graphene oxide nanoribbons” (GONRs)refers to oxygenated derivatives
of GNRs that areamphiphilic carbon nanostructures. The high specic surface area
of GNRs allows for the loading of a signicant amount of drug molecules. The functionalization of GONRs with various biomolecules is caused by oxygen-containing
functionalities, which improves theirapplicability in biomedical elds [83]. GNRs
have a exible and distinctive characteristic that allows them to go from having semiconducting properties to semimetal properties throughsimply altering their width
[84]. Additionally, the reduction processes, including electrochemical, thermal, and
chemical ones, can convert GONRs into reduced GONRs (rGONRs). GNRs offer
strong mechanical strength, good thermal and electrical conductance, and chemical
stability. Due to their oxygenatedfunctional groups, GONRs are more biocompatible than other derivatives. This characteristic enables the utilization of GONRs for
applications such as drug delivery [85], bone regeneration [86], antibacterial [87],
photothermal, biosensing, and bioimaging [88]. Chemical and other modications
are necessary to broaden the variety of applications afforded by GNRs [89]. GNRs
are the most effective carriers for anticancer drugs, certain highly aromatic pharmaceuticals, and other biomolecules.
9Fundamentals of Carbon-Based Nanomaterials
1.2.2.3 Graphene Nanoscrolls
Graphene and CNTs areamong the most intriguing nanomaterials in the carbon family owing to their perfect 1- and 2-dimensional forms. They were discovered in 2004
and 1991, correspondingly, and since then have sparked a lot of attention due to their
remarkable physicochemical characteristics [90–92] and substantial applications
[18,93,94]. The characteristics of CNTs have been thoroughly studied over the past
few years, and grapheneresearch is now quickly gaining ground alongside CNTs.
Lately, the development of unique nanostructures has been presented throughfolding and curling graphenenanosheets, which have undergone extensive investigations
[95]. This has led to the development of the intriguing carbon nanomaterial known
as the graphene nanoscroll (GNS) orcarbon nanoscroll (CNS). According to the size
of graphene nanosheetsand rolling orientation, a continuousgraphenesheet of varied chirality and diameter has been rolled up to study the GNS structure [96].GNSs
are intriguing nanostructures that, although predicted to display distinct characteristics, combine some of the comprehensive andindividualmechanical and electrical
properties demonstrated by graphene and CNTs. Due to the peculiar morphology
of GNSs, several theoretical studies have predicted their remarkable electronic and
optical properties [97,98].Since the GNSs donot havea closed-end morphologylike
CNTs, their diameter can beeasily adjusted. These characteristics may be used for a
variety of scientic applications, including chemical doping, hydrogen storage, and
nanoactuators in nanomechanical systems[98,99].
Similar to GNS, its oxidized derivative graphene oxide nanoscrolls (GONS)
have also been studied for numerous applications, including methanol oxidation,
supercapacitor, and drug delivery [100,101]. A prospective 1-D nanomorphology
of GONSwas established by the researchers Amadei et al. (2016) [102] and Fan
etal. (2015) [103] by scrolling thesingle-atomic thin GO nanosheets into a spiral
conguration. They took their inspiration from the structure of CNSand CNT. As
illustrated in Figure 1.2c [100], the GONS has an analogous 1D shape as CNT,
although with congurable interlayer spacing and additionally accessible inter-wall
region. GNS/CNS and GONS vary signicantly from each other due to the inclusion of oxygenatedfunctional groups in GONS. Despite the fact that GONS has
a poorer electric conductivity, the reduced form of GONS demonstrated superior
electrochemical performance and electric conductivity [100,103]. The aggregation
tendencyof GO sheets, their instability in the organic solvent, less porous structure,
and closed-endmorphology of CNT are the driving forces underlying the investigations associated with GONS. Moreover, the structural and morphological alteration
of GONS combined with the comparative physicochemicalcharacteristics of GO
makes it more viable to employ in real-world applications [104]. Furthermore, the
effective and rapid fabrication of GONS was aided by recent advancements in the
techniques for the synthesis of CNS.
The GONS can be fabricated through advanced synthesis approaches such as
ultrasonication, lyophilization, vertex uidic device, molecular combing, and solventinduced self-assembly methods [100]. Out of which, the ultrasonication treatment is
the most common approach employed for the synthesis of GONS of tunable dimensions. The length of nanoscrolls can be adjusted by altering the sonication parameters [104]. GO nanoscrolls exhibit higher specic surface area and surface-to-volume
ratio than GO nanosheets. Furthermore, the one-dimensional nanomorphology of
10 Carbon-Based Nanocarriers for Drug Delivery
FIGURE 1.2 (a) Scheme Demonstrating a Cross-Section of GONS Relationship between
r, ro, h, and ϕ. (b) Scheme for Rolling Up GO Nanosheets along with Axis A and Angle θ.
(c) Structural Comparison of MWCNT and GONS. [Reproduced with permission] [100].
GONS with deagglomeration tendency, suitable aqueous stability, enriched oxygen
functional groups, functionalization ability, smaller and adjustable lengths, and better biocompatibility provide signicant advantages for their application in drug delivery systems [101].
1.2.3 Two-Dimensional
1.2.3.1 Graphene
Graphene, a unique carbon allotrope, has signicantly revolutionized a number of disciplines, notably materials science, electronics, quantum physics, biomedicine, and
energy systems. Since its discovery in 2004, several investigations have been made
to understand its physicochemical properties. During the past ten years, research into
11Fundamentals of Carbon-Based Nanomaterials
the use of graphene and its derivativesin the biomedical sector has drawn a lot of
attention, notably in the elds of tissue engineering and drug and gene delivery for
the treatment of cancer. The 2-D honeycomb crystal structure of graphene is made
up of a single layer of densely packed carbon atoms. The name “graphene” is made
up of the prex “graph” for graphite and the sufx “-ene” for the C-C double bond.
Boehm, Setton, and Stumpp suggested the use of this phrase in 1994 [105,106]. Due
to the absence of oxygen-containing groups, graphene is thought to be hydrophobic. Its structure resembles multiple connected benzene rings with hydrogen atoms
replaced by carbon atoms (Figure1.3) [107].
Graphene contains one π orbital and three perpendicular σbonds to the plane.
Although the out-of-plane πbonds control the interactions among graphene layers,
the strong in-plane σ-bonds operate as the hexagonal stiff backbone chain. Modications in graphitic layers are nearly always brought on by the absence of one or
more sp2 carbon atoms or even the introduction of one or more extra atoms through
sp3 hybridization [108]. Single sp2-bonded carbon atom allotropes, which can exist in
zero to three dimensions and include fullerene, graphene, nanotubes, and graphite,
have indeed been incorporated into various polymeric composites over the past few
decades due to their exceptional mechanical, thermal, electrical, and foldable properties [109].
A wider class of graphene-based nanomaterials (GBNs) includes few-layer
graphene (FLG), GO, reduced GO (rGO), and nano GO. Although FLG is commonly
referred to as graphene, it is composed of two to ten stacked layers of graphene and
was initially created as a by-product of the manufacture of graphene [110]. Amonolayer graphene nanosheet with oxygenated functional groups, including hydroxyl,
carboxyl, and epoxide groups, all over its edges and surface makes up graphene in
its oxidized state, also known as GO. When GO is reduced chemically and thermally
in reducing conditions, the outcome is rGO, which has less oxygen composition. The
term “NGO” and “graphene nanosheets” are both used to describe graphene having
a lateral dimension of less than 100 nm.
Since the discovery of graphene in 2004, scientists have paid great attention to
its unique physicochemical properties [110,111]. Recently, numerous studies and
demonstrations of graphene applications in nanoelectronics, material science, and
engineering have been undertaken [112,113]. Nevertheless, GO, a type of graphene
FIGURE 1.3 Structure of Graphene Nanosheet.
12 Carbon-Based Nanocarriers for Drug Delivery
that has endured oxidation, has lately come to light as having signicant potential
in the biomedical eld. Despite this renewed focus, graphene and GBN have previously been used in a variety of biomedical applications, including photothermal
therapy (PTT), tissue engineering, biosensing, disease diagnostics, and drug delivery
[114,115].The properties of graphene, such as its high specic surface area attributable to the 2D at structure of the nanosheets and the adaptable surface and morphological alterations leading to their enhanced biocompatibility, contributed to its rapid
proliferation. The ability to bind or adsorb biomolecules or functional groups to both
sides of the graphene surface, permitting high functionalization and drug-loading
efciencies, is a great value addition. All things considered, graphene nanoparticles show considerably greater promise than CNTs. Although GBNs are excellent
for innovative drug delivery systems (DDSs) due to their considerable surface characteristics and improved drug loading capacity, their poor aqueous stability, biocompatibility, biodistribution, and toxicity are the main obstacles to their use in the
biomedical eld [116].
Due to its hydrophobic nature, graphene must be functionalized to be processed
and dispersed in aqueous and organic solutions [117,118]. To integrate graphene’s
outstanding properties with biological activity, a graphene surface may also be functionalized physically or chemically to accommodate biological moieties [119]. Both
covalent and non-covalent functionalization have previously been widely used to
enhance the properties of graphene [120,121]. It has also been proven that combining
covalent and non-covalent functionalization is a viable approach. Covalent functionalization often entails GO or rGO that has been chemically produced by the crosslinking of hydrophilic polymers or nucleic acids (NAs), the amine-to- carboxylate
group coupling reaction, or sulfonating methods. Nevertheless, the non-covalent
modications rely on the stabilizing properties of surfactants that attach toward the
surface through hydrophobic forces or π–π interactions on a graphene surface to
establish colloidal dispersions of graphene nanosheets [122].
Functionalization with oxygenated functional groups through the formation of
GO has multiplied the adaptability of graphene in drug delivery, cancer therapeutics,
and other biomedical applications. Furthermore, the widening of the graphene band
gap induced by doping andintercalation might aid in the development ofeffective
nanoelectronics components. The graphene-based nanomaterials potentially provide
a gateway to new domains of biotechnology unless they were biofunctionalized with
certainbiomolecules such as proteins, nucleic acids,enzymes, andpeptides [123]. In
addition, due to its aptitude to quench a variety of chemical dyes, quantum dots (QDs),
and rapid DNA sequencing, graphene has recently been recognized as a viable element
in the design of uorescence resonance energy transfer (FRET) biosensors [124].
1.2.3.2 Graphene oxide
Since its discovery, graphene has achieved extensive utility in battery electrodes
[125], biosensors [126], hydrogen storage [127,128],and supercapacitors [125,126]
due to its remarkable electrical, optical, mechanical, and thermal characteristics.
Specically, graphene nanomaterials’ signicantly larger surface area and optical
characteristics have sparked a lot of intrigue in biological applications such as biosensing and drug and gene delivery [129,130]. Nevertheless, graphene’s low water
13Fundamentals of Carbon-Based Nanomaterials
solubility owing to π-πstaking hinders its application in biomedical elds. In the
past, the parent material graphene underwent additional morphological changes and
functionalization to enhance its surface properties and prospects for a wide range of
practical applications.
Certainly, the oxidative and hydrophilic graphene derivatives GOand rGOare
enriched in hydroxyl, carboxyl, and epoxy functional entities, which improve their
stability and water dispersibility as well as their potential to emit infrared and visible light [131]. In addition to its fundamental physicochemical properties, graphene
and its derivative GO are presently the subject of comprehensive research due to
their exciting prospects for application in a variety of biomedical engineering elds,
including drug delivery, cancer therapeutics, biosensing, and tissue engineering
[132]. For many different applications, the modication of defects in nanomaterials
based on graphene is directly relevant. GO and rGO are regarded as general nanomaterials within the family of graphene-derived materials [133,134]. GOproduced
by oxidizing graphene exhibits a range of physicochemical properties. It is a hydrophilic graphene derivative and resembles a single atomic thick, two-dimensional
honeycomb structure [135]. The adjustable morphology [136] and low cytotoxicity
of GO, among other qualities, make it benecial for biological applications. It shows
uorescence in the infrared and visible portions of the electromagnetic spectrum
and Raman signals in the D, G, and 2D areas, making it suitable for bioimaging and
biosensing [136]. The oxygen-containing functional units are situated in the base and
edgingplanes of the GO nanosheets, as shown in Figure1.4 [137].
Although the fundamental structure of GO and rGO is comparable to that
of graphene, they additionally contain oxygenated functional groups in varying
amounts [135,138]. The GO has exceptional hydrophilicity because it is composed
of single-layer nanostructures that are stuffed with functional groups rich in oxygen.
FIGURE 1.4 Chemical Structure of GO. [Replicated with permission from Song et al. (2014)].
14 Carbon-Based Nanocarriers for Drug Delivery
Atraditional Hummers process and its variations are frequently used for the production of GO. Strong acids and oxidants are used in the GO production process
to introduce oxygenated functional units into the GO. The earliest approach was
reported by Brodie (1859) [139], and it was followed by Staudenmaier (1898) [140],
Hummers (1958) [141], Tour (2010) [142], Sun (2013) [143], and Peng (2015) [14 4].
Some of the disadvantages of these technologies include the low degree of oxidation,
complicated reaction conditions, poisonous gas emissions, the requirement for purication processes, and high production costs. However, the Hummers method and
its adaptations have substantially mitigated many of theserestrictions. Because of
itsfunctional groups, GO has a superior water solubility than other compounds; however, without surface functionalization, these functional groups are inadequate for
biological applications. Crucially, these oxygen-containing functional units provide
a variety of active sites for doping the elements or grafting more functional entities to
increase the surface properties of GO while maintaining its core properties [135,145].
Together with the previously mentioned characteristics, GO may be combined
with polymers and other components to develop a range of hybrids. These additions
can enhance GO’s biocompatibility, loading capacity,structural features and targetabilitywith polyacrylic acid (PAA),chitosan, polyethylene glycol (PEG), folic acid
(FA), and other substances [146]. The hydrodynamic stability of GO is likewise a
signicant issue for its use in drug administration. Owing to nonspecicbinding
and electrostatic interactions, GO does have a tendency to aggregate in physiological solutions, including proteins and salt, which hinders the formation of biological
probes [147,148]. The rigorous functionalization of GO improves its physiological
solubility and makes it more suitable for biological applications. Also, due to its
superior qualities, including a greater surface area, GO is one of the most well-liked
and thoroughly studied nanomaterials for applications involving drug administration. However, a distinct graphene derivative, rGO,has alsobeen used for a variety
of practical purposes, such as drug administration, and it can bereadily made by
thermally or chemically reducing GO [132,149].
1.2.4 Three-Dimensional
1.2.4.1 Diamond
Diamond, both natural and synthetic, is now being researched in a variety of industries. Diamond is frequently close to the top of any list describing the unique characteristics of a material [150]: crystalline diamond exhibits the largest atomic density
of any bulk crystal, products with high modulus, and superior thermal conductivity.
Broad band gap semiconductor diamond is highly translucent throughout the distant
infrared to the ultraviolet region, making it an excellent material for optical applications [2]. Diamond is appealing because it is an sp3-hybridized material that may be
transformed into a variety of topologies and congurations. Moreover, tweaking the
growth conditions leads to CVD diamond lms that range from microcrystalline to
ultra-nanocrystalline. Ultra-nanocrystalline lms made of diamond offer the benet of having smooth surfaces, less strain, and better-breaking resistance. Diamond
domains with narrow sp
guishing feature of such lms. The most intriguing types of diamond that have been
2
borders, measuring at least 10 nm in size, are a distin-
15Fundamentals of Carbon-Based Nanomaterials
Данная книга находится в списке для перевода на русский язык сайта https://meduniver.com/
investigated for use in drug delivery or clinical applications are nanoscale diamond
particles (also known as nanodiamonds, NDs), and diamond nano-lms. Diamond
is typically regarded as a biocompatible material because of its chemical and biochemical impermeability, which means that it is chemically non-cytotoxic when in
interaction with living cells [151]. As a result, diamond is a material that may be used
to cover medical equipment, develop articial tissues, or facilitate the development
of living cells. For the development of various cell phenotypes, such as neurons,
broblasts, osteoblasts, and several other cell lines, ND nanoparticles and nanoplatelets have been utilized as substrates [2]. Fluorescent nanodiamonds (FNDs) were
employed by Guarina etal. (2018)to assess the functional effects of these materials
on hippocampal neurons utilizing multielectrode array (MEA)recordings. Based on
the embryonic stage of incubation with FNDs, the activation frequency of neurons
was inuenced differentially (seven versus 14). During 14 days in-vitro, FNDs sig-
nicantly decreased the frequency of neuronal activity [152].
Diamond consistently showed minimal detectable cytotoxicity, and in some situations, it even seemed to encourage cell adhesion and growth compared to more
traditional substances like glass or cell culture polystyrene. Due to their unique
chemical and electrical characteristics and resilience, NDs were utilized in neuroscience in addition to being used as a growing substrate to design biosensors for monitoring neural activity [153]. Nanowires made of diamond must also be taken into
account. Diamond nanowires are thought to help with problems like selectivity and
sensitivity that are relevant to enhancing the overall effectiveness of sensors [2,154].
Diamond-based materials provide special benets over traditional substances in the
domain of cellular detection [155], which subsequently results from the material’s
exceptional physicochemical characteristics, such as mechanical resilience, broad
spectral transparency, and thermal conductivity [156]. Diamond-based platforms are
cytocompatibleand substantially better at supporting cell adhesion and proliferation than normal substrates, according to in-vitro testing [157]. However, the pure
diamond surface’s biochemical inertness does not prevent it from effectively chemically functionalizing when terminated with certain covalent bonds, which enables
the attachment of a wide range of molecules, including DNA strands [158].
Although diamond-based substrates appear to have a bright future, it must be
highlighted that their potential for biological applications, particularly in the domain
of neurosciences, is currently constrained. Perhaps in the future, like in the instance
of GO, appropriate tuning of the nanomaterial’s physicochemical andmorphologicalfeatures will aid in overcoming its present signicant limits.
1.3 CHARACTERIZATION TECHNIQUES FOR CBNS
The CBNsmust be thoroughly investigated after synthesis to ensure the quality of
the product (quality, defects, functional groups, morphology, and structure, etc.)
and to clarify their composition. Several characterization approaches may be used
to explore the attributes of CBNs and CBN-basednanocomposites. These methods
comprise electron microscopy (SEM and TEM), Fourier transform infrared spectroscopy (FTIR), UV-Vis spectroscopy, atomic force microscopy (AFM), X-ray
photoelectron spectroscopy (XPS),energy dispersive X-ray analysis (EDX),Raman
Соседние файлы в папке Библиотека им академика М.И. Перельмана