Chemical Design of Carbon-Coated Al2o3 Nanoparticles
The novel approach to chemical design of carbon-coated Al2O3 nanoparticles with an average particle size of 8-10 nm was developed. Carbon coating was synthesised by modification of fumed alumina support with 4,4’-methylenebis-(phenylisocyanate) and its subsequent pyrolysis at 700oC. In order to synt...
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| Опубліковано в: : | Хімія, фізика та технологія поверхні |
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| Дата: | 2010 |
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| Мова: | Англійська |
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Інститут хімії поверхні ім. О.О. Чуйка НАН України
2010
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| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Цитувати: | Chemical Design of Carbon-Coated Al2o3 Nanoparticles / L.F. Sharanda, I.V. Babich, Yu.V. Plyuto // Хімія, фізика та технологія поверхні. — 2010. — Т. 1, № 3. — С. 326-332. — Бібліогр.: 30 назв. — англ. |
Репозитарії
Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1860243987835650048 |
|---|---|
| author | Sharanda, L.F. Babich, I.V. Plyuto, Yu.V. |
| author_facet | Sharanda, L.F. Babich, I.V. Plyuto, Yu.V. |
| citation_txt | Chemical Design of Carbon-Coated Al2o3 Nanoparticles / L.F. Sharanda, I.V. Babich, Yu.V. Plyuto // Хімія, фізика та технологія поверхні. — 2010. — Т. 1, № 3. — С. 326-332. — Бібліогр.: 30 назв. — англ. |
| collection | DSpace DC |
| container_title | Хімія, фізика та технологія поверхні |
| description | The novel approach to chemical design of carbon-coated Al2O3 nanoparticles with an average particle size of 8-10 nm was developed. Carbon coating was synthesised by modification of fumed alumina support with 4,4’-methylenebis-(phenylisocyanate) and its subsequent pyrolysis at 700oC. In order to synthesise the samples with increased carbon content, the grafting-pyrolysis cycle was repeated. The above mentioned synthetic route resulted in the samples with carbon loading of 7.6 and 14.5 wt. %. Characterisation of the synthesised samples with Raman, FTIR, TG/DTG-DTA, N2 adsorption and SEM techniques revealed the formation of continuous carbon coating on the surface of Al2O3 nanoparticles after the first grafting-pyrolysis cycle. The increase of the carbon loading on the alumina surface to 14.5 wt. % (two grafting-pyrolysis cycles) resulted in the formation of the carbon coating with more regular graphitic structure.
Розроблений новий метод хімічного дизайну вуглецевого покриття на поверхні наночастинок пірогенного Al2O3 розміром 8–10 нм. Вуглецеве покриття синтезували шляхом модифікування поверхні пірогенного оксиду алюмінію 4,4-метилендифенілдиізоціанатом та подальшим його піролізом при 700oC. З метою одержання зразків з більш високим вмістом вуглецю цикл "модифікування–піроліз" повторювали. Вищеописана процедура дозволила синтезувати зразки з вмістом вуглецю 7,6 та 14,5 % ваг. Дослідження синтезованих зразків методами раманівської та ІЧ-спектроскопії, TГ/ДTГ-ДTA, низькотемпературної адсорбції азоту та СЕM показало, що утворення суцільного вуглецевого покриття на поверхні пірогенного Al2O3 відбувається вже після проведення першого циклу "модифікування–піроліз". Повторення циклу "модифікування–піроліз" МДІ приводить до формування вуглецевого покриття з більш впорядкованою графітовою структурою.
Разработан новый метод химического дизайна углеродного покрытия на поверхности наночастиц пирогенного Al2O3 размером 8–10 нм. Углеродное покрытие было синтезировано путем модифицирования поверхности пирогенного оксида алюминия 4,4–метилендифенилдиизоцианатом с последующим его пиролизом при 700oC. Для того чтобы синтезировать образцы с более высоким содержанием углерода, цикл "модифицирование–пиролиз" повторяли. Описанная выше процедура позволила синтезировать образцы с содержанием углерода 7,6 и 14,5% вес. Исследование синтезированных образцов методами рамановской и ИК-спектроскопии, TГ/ДTГ-ДTA, низкотемпературной адсорбции азота и СЭM показало, что образование сплошного углеродного покрытия на поверхности пирогенного Al2O3 происходит уже после проведения первого цикла "модифицирование–пиролиз". Повторение цикла "модифицирование–пиролиз" МДИ приводит к формированию углеродного покрытия с более упорядоченной графитовой структурой.
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_____________________________________________________________________________________________
* Corresponding author lyusharanda@yahoo.com
326 ���� 2010. � . 1. � 3
UDC 544.723.214+544.72.023.2+549.521.4+54-31+546.26.-162
CHEMICAL DESIGN OF CARBON-COATED
Al 2O3 NANOPARTICLES
L.F. Sharanda*, I.V. Babich, Yu.V. Plyuto
Chuiko Institute of Surface Chemistry of National Academy of Sciences of Ukraine
17 General Naumov Street, Kyiv 03164, Ukraine
The novel approach to chemical design of carbon-coated Al2O3 nanoparticles with an average particle
size of 8-10 nm was developed. Carbon coating was synthesised by modification of fumed alumina support
with 4,4’-methylenebis-(phenylisocyanate) and its subsequent pyrolysis at 700oC. In order to synthesise the
samples with increased carbon content, the grafting-pyrolysis cycle was repeated. The above mentioned syn-
thetic route resulted in the samples with carbon loading of 7.6 and 14.5 wt. %. Characterisation of the syn-
thesised samples with Raman, FTIR, TG/DTG-DTA, N2 adsorption and SEM techniques revealed the forma-
tion of continuous carbon coating on the surface of Al2O3 nanoparticles after the first grafting-pyrolysis cy-
cle. The increase of the carbon loading on the alumina surface to 14.5 wt. % (two grafting-pyrolysis cycles)
resulted in the formation of the carbon coating with more regular graphitic structure.
INTRODUCTION
The carbon films have attracted considerable
attention due to their unique properties including
chemical and mechanical stability, electrical con-
ductivity, optical transparency, and low friction
coefficient. Combination of physicochemical
properties of individual carbon and alumina in car-
bon-coated alumina results in novel materials
promising for the development of dense electri-
cally conductive ceramic [1] and fillers [2], mem-
branes [3], solar absorbers [4], catalyst supports
and catalysts [5], protective coating [6]. It is well
established that the properties, structures and uni-
formity of carbon film and the degree of surface
coverage of the support strongly depend on the
preparation conditions, carbon source, deposition
parameters and the supports chemical nature [1–6].
Therefore, a number of approaches for the synthesis
of such carbon-coated materials has been reported.
The first approach proposed by Youtsey et al.
[2] and intensively used by Leboda et al. [7] is
based on the ability of organic compounds to be
pyrolysed on the surface of the alumina and silica-
alumina supports at elevated temperatures that is
accompanied by carbon deposition. Among the
tested organic substances pyrolysable in the range
of 600–700oC, are such hydrocarbons as hexane,
benzene, toluene, naphthalene, anthracene, cyclo-
hexane and cyclohehene which was found to be
the most promising for making carbon-alumina
and carbon-silica-alumina composite materials.
Pyrolysis of organic alcohols like n-heptyl and
benzyl proceeds at lower temperatures [8].
An alternative approach was developed by
Pratsinis et al. [9] who proposed a continuous, one-
step flame-synthesis of carbon-coated titania and
silica nanostructured particles. The diffusion flame
aerosol reactor is used for simultaneous combustion
of organic and inorganic sources. In both one-step
methods the formation of separate carbon phase
along the carbon coating cannot be completely ex-
cluded because of the applied synthesis conditions.
The present work aims at the development of
two-step approach for the synthesis of carbon-
coated nanoparticles. It is based on chemical graft-
ing of 4,4’-methylenebis(phenylisocyanate) (MDI)
on the support surface and subsequent pyrolysis of
the resulting surface species in vacuum. The method
was demonstrated for chemical design of carbon-
coated Al2O3 nanoparticles whose detailed physico-
chemical characterisation was performed.
EXPERIMENTAL
Non-porous fumed alumina
(SBET(N2)=155 m2g-1) with an average particle
size of 5–8 nm, prepared by the hydrolysis of
aluminium chloride in a hydrogen/oxygen flame,
was used as the alumina support. MDI was ob-
tained from Bayer AG and used without further
purification. The weighted amount (4.5 g) of
fumed alumina was contacted with 100 ml of
0.04 M o-xylene solution of MDI at room tem-
perature for 24 h at periodic stirring. The product
Chemical Design of Carbon-Coated Al2O3 Nanoparticles
_____________________________________________________________________________________________
���� 2010. � . 1. � 3 327
was filtered, washed out with 200 ml of pure
o-xylene, dried at 60oC for 2 h. Then, the sample
was placed into a quartz cell and evacuated at
700oC and a pressure of 1×10-2 Pa for 2 h in order
to complete pyrolysis of the grafted MDI. To pre-
pare the samples with increased carbon content,
the grafting-pyrolysis cycle was repeated. The
above procedure resulted in samples with carbon
content of 7.6 and 14.5 wt. % denoted hereafter
as C(7.6)/Al2O3 and C(14.5)/Al2O3, respectively.
The Raman spectra were performed by an auto-
mated double spectrometer DFC-24 (LOMO, Rus-
sia) using excitation of Ar ion laser at � =514.5 nm.
FTIR spectra in a reflectance mode were re-
corded in the range from 4000 to 400 cm-1 with a
spectral resolution of 8 cm-1 using a Nexus Nicolet
FTIR spectrometer (Thermo Scientific) equipped
with a Smart Collector reflectance accessory. Alu-
mina samples were powdered with KBr in 1:10 ratio.
Thermal studies (TG/DTG-DTA) were car-
ried out with a STA-1500 H thermobalance (PL
Thermal Sciences) at a heating rate of 10oC/min
in an air flow of ~50 cm3/min. The carbon content
in the synthesised samples was determined gra-
vimetrically from the weight loss within the tem-
perature interval of 300–700oC.
The surface area (BET) and porosity were
determined by nitrogen adsorption/desorption at
-196oC using a Quantachrome Autosorb-6B
equipment. The samples were preliminary heated
in vacuum at 150oC for 16 h.
X-ray diffraction (XRD) patterns were re-
corded in the range 5–80o (scanning step 0.1o)
with a DRON-3M automated diffractometer using
the Cu-Ka (l= 1.54178Å) radiation and Ni filter.
SEM images were obtained with a LEO 1550
high resolution electron microscope. An electron
beam of 2.5 kV was used to analyse the surface
details of the samples.
RESULTS AND DISCUSSION
4,4’-methylenebis(phenylisocyanate) was se-
lected as carbon precursor because of extraordi-
nary reactivity of �N=C=O groups and high car-
bon content. It is well know that addition of or-
ganic isocyanates to the compounds containing
mobile hydrogen atom (i.e. water, amines, carbox-
ylic acids, alcohols) leads to urethane or urea
group generation [10, 11]. The high reactivity of
isocyanates toward nucleophilic reagents is mainly
connected with electrophilic character of the car-
bon atom in �N=C=O functional group [10, 11].
Thus, the formation of surface complexes of 4,4’-
methylenebis(phenylisocyanate) on the alumina
surface should be expected due interaction of car-
bon atom of isocyanate group and oxygen atom of
hydroxyl group of the alumina support that results
in simultaneous transfer of the proton to the nitro-
gen atom. The reaction between the hydroxyl
group of the alumina surface and isocyanate group
can be illustrated as follows (Fig. 1).
Al O H
NCO R
Al O H
NCO R
Fig. 1. Schematic representation of the reaction of
�N=C=O groups of MDI with OH groups of
Al 2O3 nanoparticles
Upon the contact of Al2O3 nanoparticles with
MDI dissolved in o-xylene, their initial white
colour immediately turned yellow that is accom-
panied by discoloration of the solution. The re-
sulting MDI species appeared to be strongly
bound to the support surface since the modified
Al 2O3 nanoparticles do not loose yellow colour
even after washing with o-xylene. This confirms
that the reaction of �N=C=O groups of MDI with
OH groups at the alumina surface results in the
formation of the surface organic moiety.
Fig. 2 shows the SEM images of the initial
fumed Al2O3 nanoparticles in comparison with Al2O3
nanoparticles whose surface was involved into inter-
action with 4,4’-methylenebis(phenylisocyanate).
In the SEM image of the initial fumed alumina
one can see the individual Al2O3 nanoparticles with
an average particle size of 5–8 nm and also their ag-
glomerates with a size about 50–100 nm (Fig. 2a).
The morphology of Al2O3 nanoparticles after interac-
tion with 4,4’-methylenebis(phenylisocyanate) dif-
fers significantly (Fig. 2b) from that of the initial
fumed alumina. One can clearly see the distinct
boundaries between Al2O3 nanoparticles. This can
indicate that surface MDI species at the alumina sur-
face cover each individual Al2O3 nanoparticle that
results in their separation from one another.
FTIR spectroscopy proves the chemical inter-
action of isocyanate group (�N=C=O) of MDI
with OH groups of Al2O3 nanoparticles.
First, in FTIR spectrum of MDI (Fig. 3a), a dis-
tinct absorption band at 2278 cm-1 typical for isocy-
anate group (�N=C=O) is observed [12]. This band
is not present in the spectrum of the alumina sample
which contacted with MDI (Fig. 3b). Instead, one
can see the intensive broad bands centred at 3520
and 3340 cm-1 which correspond to free and hydro-
gen bonded N�H groups, respectively [13].
L.F. Sharanda, I.V. Babich, Yu.V. Plyuto
_____________________________________________________________________________________________
328 ���� 2010. � . 1. � 3
a
b
Fig. 2. a – SEM images of the initial Al2O3 nanoparti-
cles; b – after their interaction with 4,4’-
methylenebis(phenylisocyanate)
���
400100016002200280034004000
Wavenumber (cm -1)
R
ef
le
ct
an
ce
(
a.
u.
)
a
b
c
3340 2278
1678
1710
1512
1319
1524
1512
1240
1319
1670
3300
3520
2291
Fig. 3. a – FTIR spectra of individual MDI, b – MDI
on the surface of Al2O3 nanoparticles c –
C(7.6)/Al2O3 sample
Second, when MDI interacts with the alumina
surface, the appearance of the new absorption band
at 1670 cm-1 and the shoulder around 1545 cm-1
which can be assigned to so-called Amide I and
Amide II vibrations in amide groups �NH�C(O)� is
observed (Fig. 3b). Besides, the new absorption
bands at 1319 cm-1 which is due to (N�H) + (C�N)
stretching vibrations and at 1240 cm-1 attributed to
the C�N stretching vibrations of amide group ap-
peared [12, 14]. This also confirms the formation of
surface MDI species according to Fig. 1.
Besides, the formation of surface MDI species
can also proceed via interaction of �N=C=O groups
with coordinatively unsaturated Al3+ acid sites on
the alumina surface. It has been found earlier [15]
that �N=C=O groups posses very strong electron-
donor property and may be used to identify even
very weak Lewis acid sites of the alumina surface.
One can also see that the band at 2278 cm-1
associated with �N=C=O groups is not present in
the spectrum of the carbon-coated alumina sam-
ple which contacted with MDI (Fig. 3c). In addi-
tion, the bands at 1678 and 1545 cm-1 which indi-
cate the formation of the amide bonds (NH�CO)
is observed. This allowed us to conclude that the
carbon-coated alumina possesses the surface
functional groups which can be involved into
strong interaction with MDI molecules.
It is necessary to note the difference between
MDI grafting on the initial and carbon-coated Al2O3
nanoparticles. In contrast to MDI grafted on the sur-
face of Al2O3 nanoparticles (Fig. 3b), in FTIR spec-
trum of MDI on the surface of C(7.6)/Al2O3 sample
(Fig. 3c) only a weak broad band centered at
3300 cm-1 connected with hydrogen-bonded N�H
groups is seen. Moreover, the band which can be
assigned to free N�H groups is not present at all.
This reflects substantial changes of the nature of the
adsorption sites due to shielding of the alumina sur-
face with the deposited carbon.
The surface loading of Al2O3 nanoparticles
with MDI species and carbon coating was deter-
mined by thermal analysis using TG/DTG-DTA
technique (Table 1).
Table 1. Quantitative data on MDI grafting on Al2O3
nanoparticles, carbon yield upon pyrolysis of
surface MDI species and carbon loading
Pyrolysis of grafted
MDI
Sample Carbon
loading,
wt. %
Grafted
MDI,
wt. % yield of
elemental
carbon,
%
final
carbon
loading,
wt. %
SBET
(N2 ),
m2/g
Al 2O3 0 19.2 55.0 7.6 155.0
C(7.6)/
Al 2O3
7.6 12.8 75.0 14.5 155.0
C(14.5)/
Al 2O3
14.5 – – – 155.0
Chemical Design of Carbon-Coated Al2O3 Nanoparticles
_____________________________________________________________________________________________
���� 2010. � . 1. � 3 329
One can see that on the surface of Al2O3
nanoparticles the amount of grafted MDI reaches
19.2 wt. %. The carbon loading in this sample after
pyrolysis was 7.6 wt. % that corresponds to 55% of
carbon yield. The amount of MDI grafted on the
C(7.6)/Al2O3 sample appeared to be somewhat lower
as compared to that on the initial alumina support.
Meanwhile, the carbon yield after pyrolysis was suf-
ficiently higher (75.0%). After two-fold repetition of
the grafting-pyrolysis cycle the carbon loading on the
surface of Al2O3 nanoparticles was 14.5 wt. %.
Thermoanalytical characterisation of the syn-
thesised carbon coated Al2O3 nanoparticles exhib-
its the intense weight loss in DTG patterns around
500oC that coincides with the exothermic peak in
DTA curves. Oxidation started at 300oC and pro-
ceeded in one step up to 700oC. This suggests that
oxidation of a single carbon phase occurs.
The nitrogen adsorption-desorption isotherms
confirmed that carbon coating did not change the
textural characteristics of Al2O3 nanoparticles
(see Fig. 4).
0
150
300
450
600
750
900
0,0 0,2 0,4 0,6 0,8 1,0
Relative Pressure (P 0/Ps)
A
ds
or
pt
io
n
(c
m
3 /g
)
c
a
b
Fig. 4. Nitrogen adsorption-desorption isotherms on
Al2O3 nanoparticles – a, C(7.6)/Al2O3 – b
and C(14.5)/Al2O3 – c samples
The nitrogen adsorption-desorption isotherms
of the initial Al2O3 nanoparticles and carbon-coated
samples (Fig. 4) can be identified as the type II iso-
therms according to IUPAC classification and are
typical for non-porous materials [16]. The surface
area values of the initial and carbon-coated Al2O3
nanoparticles are similar as well (see Table 1).
This means that the structure and particles size of
the initial fumed Al2O3 nanoparticles were not
changed upon carbon deposition. The difference is
observed only in the region near saturation pres-
sure of the volume adsorption for both
C(7.6)/Al2O3 and C(14.5)/Al2O3 samples where
adsorption appeared to be increased significantly
in comparison with the initial Al2O3 nanoparticles.
Most likely this is due to the decrease of close
packing of the primary Al2O3 nanoparticles when
their surface is covered with carbon coating.
Raman spectroscopy was used to characterise the
structure of carbon coatings on the alumina surface.
The Raman spectrum of C(7.6)/Al2O3 sample
(Fig. 5a) consists of two bands, namely a broad
asymmetric band centred at 1585 cm-1 which re-
lates to sp2-bonded carbon of mono-crystalline
graphite (known as G-band) and the band at
1365 cm-1 which is associated with disorder in the
graphite lattice (known as D-band) [17–23]. The
presence of such well resolved broad Raman bands
indicates the formation of the carbon coating with
amorphous structure [17–19] on the surface of
fumed Al2O3 after the first grafting-pyrolysis cycle.
�
1 2 001 30014 001 50016 001 700
Ra m a n shift (cm -1)
In
te
ns
ity
(
a
.u
.)
1 592
1365
1 585
1365
a
b
G - ba nd
D- ba nd
Fig. 5. Raman spectra of C(7.6)/Al2O3 – a, and
C(14.5)/Al2O3 – b samples
The bandwidth and the intensity of both D-
and G-bands in Raman spectrum of C(14.5)/Al2O3
sample are decreased substantially (Fig. 5b). This
can indicate the formation of the less defective
disordered graphite structure and the increase of
the number and/or the size of sp2 domains after the
repetition of the grafting-pyrolysis cycle [20].
It is important to mention that the Raman spec-
trum of C(14.5)/Al2O3 sample appeared be very
similar to that of the cathode outer shell carbon
materials [24] or polycrystalline graphite produced
by ball milling of the graphite powder [23]. It
should be also noted that similar transformations
are observed in Raman spectra of amorphous car-
bon films upon thermal treatment [20–24]. Usu-
ally, such transformations in carbon materials
(know as graphitisation) occur at high tempera-
tures (over 1200oC) but can also proceed at lower
temperatures in the presence of catalysing agents
like ceramic oxides [1]. Therefore, we suppose that
L.F. Sharanda, I.V. Babich, Yu.V. Plyuto
_____________________________________________________________________________________________
330 ���� 2010. � . 1. � 3
alumina surface promotes ordering of the amor-
phous carbon coating at lower temperature.
The analysis of FTIR spectra also suggests
the existence of graphite-like carbon structure on
the alumina surface (Fig. 6a,b).
400100016002200280034004000
Wavenumber (cm -1)
In
te
ns
ity
(
a.
u.
)
b
a
3510
1550
1588
1340
1250
1325
845
3300
740
810
590
3300
3050
Fig. 6. FTIR spectra of C(7.6)/Al2O3 – a and
C(14.5)/Al2O3 – b samples
As can be seen, the FTIR spectrum of
C(7.6)/Al2O3 sample (Fig. 6a) exhibits the band at
1588 cm-1 which is attributed to typical aromatic
ring vibrations (sp2-C�C) [17, 23–29]. The band
centered at 1250 cm-1 indicates the existence of de-
fects in graphitic structure [25]. Besides, the bands
centred at 1340 and 3510 cm-1 which can be as-
signed to C�N and N�H groups, respectively, are
observed as well [28–30].
FTIR spectrum of C(14.5)/Al2O3 sample is
shown in Fig. 6b. As one can see, repetition of the
grafting-pyrolysis cycle results in substantial change
of FTIR spectrum in the region of 4000–400 cm-1.
The band at 1588 cm-1 shifted to 1550 cm-1 and be-
came considerably less intensive. This indicated the
increase of the size of the graphitic domains in car-
bon coating on the alumina surface [25, 26]. Be-
sides, the band near 1340 cm-1 which relates to
stretching vibrations of C�N groups shifted to
1325 cm-1 while the band at 1250 cm-1 which corre-
sponds to disordered graphite-like structure disap-
peared. These changes clearly indicate that the in-
crease of the carbon loading on the alumina sur-
face to 14.5 wt. % resulted in the formation of the
carbon coating with less defective graphitic struc-
ture [25]. One can also see the bands at 740 and
845 cm-1 which are due to the presence of C�H
groups in aromatic rings [17, 25] and/or aromatic
impurities in graphite [26]. In Fig. 6b the band at
3510 cm-1 is not observed and the spectrum exhib-
its the presence of very weak bands centred at
3300 and 3050 cm-1 which can be related to C�H
groups in different configuration [17, 25, 28].
a
b
Fig. 7. SEM images of the carbon-coated C(7.6)/Al2O3
– a and C(14.5)/Al2O3 – b samples
The observed changes can indicate that popu-
lation of surface functional surface groups in
C(14.5)/Al2O3 sample is smaller in comparison
with that in C(7.6)/Al2O3 sample. Besides, we can
also come to the conclusion that the surface struc-
ture of carbon coating in C(7.6)/Al2O3 and
C(14.5)/Al2O3 samples differs significantly. The
carbon coating after the first grafting-pyrolysis
cycle possesses the defective structure and the
repetition of the grafting-pyrolysis cycles results
in the formation of more uniformed and less de-
fective carbon coating on the alumina surface.
The surface morphology of the synthesised
carbon-coated Al2O3 nanoparticles was examined
by SEM (Fig. 7).
The morphology of the carbon-coated Al2O3
nanoparticles (Fig. 7a,b) differs significantly from the
initial Al 2O3 nanoparticles (Fig. 2a). The SEM im-
ages of both C(7.6)/Al2O3 and C(14.5)/Al2O3 sam-
ples showed the spherical, non-agglomerated
nanoparticles with the size of 8–10 nm that indicates
the covering of the surface of individual Al2O3
nanoparticles with a carbon coating. Thus, the forma-
tion of continuous carbon coating on the alumina
surface occurs after the first grafting-pyrolysis cycle.
Chemical Design of Carbon-Coated Al2O3 Nanoparticles
_____________________________________________________________________________________________
���� 2010. � . 1. � 3 331
CONCLUSIONS
Novel approach to chemical design of carbon-
coated Al2O3 nanoparticles was developed. The syn-
thesis of carbon coating on fumed Al2O3 nanoparti-
cles is based on grafting of 4,4’-methylenebis
(phenylisocyanate) (MDI) that proceeds via reaction
of isocyanate groups (�N=C=O) with hydroxyl
groups on the alumina surface and subsequent pyro-
lysis of surface MDI species at 700oC in vacuum.
The formation of continuous carbon coating on the
Al2O3 nanoparticles surface occurred after the first
grafting-pyrolysis cycle. The increase of the carbon
loading on the alumina surface to 14.5 wt. % (two
grafting-pyrolysis cycles) resulted in the formation
of the carbon coating with more regular graphitic
structure. The SEM images of the synthesised alu-
mina samples showed the presence of spherical,
non-agglomeration carbon-coated Al2O3 nanoparti-
cles with the size of 8–10 nm.
REFERENCES
1. Menchavez R.L., Fuji M., Takahashi M. Elec-
trically conductive dense and porous alumina
with in-situ-synthesized nanoscale carbon
networks // Adv. Mater. – 2008. – V. 20,
N 12. – P. 2345–2351.
2. Pat. 4018943 United States, Method of forming
a conducting material for a conducting device /
K.J Youtsey et al. – Appl. No.: 05/226035;
Filing: 14.02.1972; Publ.: 19.04.1977. – 8 p.
3. Pat. 5262198 United States, Method of pro-
ducing a carbon coated ceramic membrane
and associated product / P.K.T. Liu et al. –
Appl. No.: 07/682181; Filing: 08.04.1991;
Publ.: 16.11.1993. – 11 p.
4. Katumba G., Lu J., Olumekor L. et al. Low
cost selective solar absorber coatings: charac-
teristics of carbon-in-silica synthesized with
sol-gel technique // J. Sol-Gel Sci. Technol. –
2005. – V. 36, N 1. – P. 33–43.
5. Zhang T., Jacobs P.D., Haynes H.W. Laboratory
evaluation of four coal liquefaction catalysts pre-
pared from modified alumina supports // Catal.
Today. – 1994. – V. 19, N 3. – P. 353–366.
6. Mann M., Shter G.E., Grader G.S. Preparation
of carbon coated ceramic foams by pyrolysis
of polyurethane // J. Mater. Sci. – 2006. –
V. 41, N 18. – P. 6046–6055.
7. Leboda R., Charmas B., Marciniak M., Skubi-
szewska-Zieba J. On the topography and mor-
phology of carbon deposits prepared by pyrolysis
of alcohol on the surface of silica gel // Mater.
Chem. Phys. – 1999. – V. 58, N 2. – P. 146–155.
8. Boorman P.M., Chong K. Preparation of car-
bon-covered alumina using fluorohydrocar-
bons. A new acidic support material // Appl.
Catal. A. – 1993. – V. 95, N 2. – P. 197–210.
9. Kammler H.K., Pratsinis S. Carbon-coated
titania nanostructured particles: continuonus,
one-step flame-synthesis // J. Mater. Res. –
2003. – V. 18, N 11. – P. 2670–2676.
10. Caraculacu A.A., Coseri S. Isocyanates in
polyaddition processes. Structure and reaction
mechanisms // Prog. Polym. Sci. – 2001. –
V. 26, N 5. – P. 799–851.
11. Krol P. Synthesis methods, chemical struc-
tures and phase structures of linear polyure-
thanes. Properties and applications of linear
polyurethanes in polyurethane elastomers, co-
polymers and ionomers // Prog. Mater. Sci. –
2007. – V. 52, N 6. – P. 915–1015.
12. Dechant J. Ultrarotspektroskopische Untersu-
chungen an Polymeren / Ed. R. Danz
W. Kimmer, R. Schmolke. – Akademie-
Verlag-Berlin, 1972. – 347 p.
13. Stankovich S., Piner R.D., Nguyen S.T.,
Ruoff R.S. Synthesis and exfoliation of
isocyanate-treated grapheme oxide nanoplate-
lets // Carbon. – 2006. – V. 44. – P. 3342–3347.
14. Zhao C., Ji L., Liu H. et al. Functionalized
carbon nanotubes containing isocyanate
groups // J. Solid State Chem. – 2004. –
V. 177, N 12. – P. 4394–4398.
15. Davydov A. Molecular Spectroscopy of Oxide
Catalyst Surfaces / Ed. N.T. Sheppard. – John
Wiley & Sons Ltd, England, 2003. – 684 p.
16. Gregg S.J., Sing K.S.W., Adsorption, Surface
Area and Porosity. – London, New York:
Academic Press, 1967. – 303 p.
17. Robertson J. Amorphous carbon // Adv. Phys. –
1986. – V. 35, N 4. – P. 317–374.
18. Ferrari A.C., Robertson J. Interpretation of
Raman spectra of disordered and amorphous
carbon // Phys. Rev. B. – 2000. – V. 61, N 20. –
P. 14095–14107.
19. Ferrari A.C. Raman spectroscopy of grapheme
and graphite: disorder, electron-phonon cou-
pling, doping and nonadiabatic effects // Solid
State Commun. – 2007. – V. 143. – P. 47–57.
20. Theodoropoulou S., Papadimitriou D., Zoum-
poulakis L., Simitzis J. Structural and optical
characterization of pyrolytic carbon derived
L.F. Sharanda, I.V. Babich, Yu.V. Plyuto
_____________________________________________________________________________________________
332 ���� 2010. � . 1. � 3
from novolac resin // Anal. Bioanal. Chem. –
2004. – V. 379, N 5–6. – P. 788–791.
21. Prawer S., Rozenblum I., Orwa J.O., Adler J.
Identification of the point defects in diamond as
measured by Raman spectroscopy: comparison
between experiment and computation // Chem.
Phys. Lett. – 2004. – V. 390, N 4–6. – P. 458–461.
22. Takahiro K., Ookawa R., Kawatsura K. et al.
Improvement in surface roughness of nitro-
gen-implanted glassy carbon by hydrogen
doping // Diamond Relat. Mater. – 2003. –
V. 12, N 8. – P. 1362–1367.
23. Shen T.D., Ge W.Q., Wang K.Y. et al.. Struc-
tural disorder and phase transformation in
graphite produced by ball milling // Nanostruct.
Mater. – 1996. – V. 7, N 4. – P. 393–399.
24. Eklund P.C., Holden J.M., Jishi A. Vibrational
modes of carbon nanotubes: spectroscopy and
theory // Carbon – 1995. – V. 33. – P. 959–972.
25. Ros T.G., Dillen A.J., Geus J.W, Koningsber-
ger D.Ch. Surface structure of untreated par-
allel and fishbone carbon nanofibres: an in-
frared study // Chem. Phys. Chem. – 2002. –
V. 3, N 2. – P. 393–399.
26. Friedel R.A., Carlson G.L. Infrared spectra of
ground graphite // J. Phys. Chem. – 1971. –
V. 75, N 8. – P. 1149–1151.
27. Rodil S.E., Muhl S., Masa S., Ferrari A.C. Opti-
cal gap in carbon nitride films // Thin Solid
Films. – 2003. – V. 433, N 1–2. – P. 119–125.
28. Rusop M., Omer A.M.M., Adhikari S. et al.
Effect of annealing temperature on the opti-
cal, bonding, structural and electrical proper-
ties of nitrogenated amorphous carbon thin
films grown by surface wave microwave
plasma chemical vapor deposition // J. Mater.
Sci. – 2006. – V. 41, N 2. – P. 537–547.
29. Vasilets V.N., Hirose A., Yang Q. et al. Char-
acterization of doped diamond-like carbon
films deposited by hot wire plasma sputtering
of graphite // Appl. Phys. A. – 2004. – V. 79,
N 8. – P. 2079–2084.
30. Yang L., May P.W, Vin L. et al. Ultra fine
carbon nitride nanocrystals synthesized by la-
ser ablation in liquid solution // J. Nanopart.
Res. – 2007. – V. 9, N 6. – P. 1181–1185.
Received 07.07.2010, accepted 17.08.2010
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| id | nasplib_isofts_kiev_ua-123456789-29002 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 2079-1704 |
| language | English |
| last_indexed | 2025-12-07T18:33:57Z |
| publishDate | 2010 |
| publisher | Інститут хімії поверхні ім. О.О. Чуйка НАН України |
| record_format | dspace |
| spelling | Sharanda, L.F. Babich, I.V. Plyuto, Yu.V. 2011-11-27T17:50:02Z 2011-11-27T17:50:02Z 2010 Chemical Design of Carbon-Coated Al2o3 Nanoparticles / L.F. Sharanda, I.V. Babich, Yu.V. Plyuto // Хімія, фізика та технологія поверхні. — 2010. — Т. 1, № 3. — С. 326-332. — Бібліогр.: 30 назв. — англ. 2079-1704 https://nasplib.isofts.kiev.ua/handle/123456789/29002 544.723.214+544.72.023.2+549.521.4+54-31+546.26.-162 The novel approach to chemical design of carbon-coated Al2O3 nanoparticles with an average particle size of 8-10 nm was developed. Carbon coating was synthesised by modification of fumed alumina support with 4,4’-methylenebis-(phenylisocyanate) and its subsequent pyrolysis at 700oC. In order to synthesise the samples with increased carbon content, the grafting-pyrolysis cycle was repeated. The above mentioned synthetic route resulted in the samples with carbon loading of 7.6 and 14.5 wt. %. Characterisation of the synthesised samples with Raman, FTIR, TG/DTG-DTA, N2 adsorption and SEM techniques revealed the formation of continuous carbon coating on the surface of Al2O3 nanoparticles after the first grafting-pyrolysis cycle. The increase of the carbon loading on the alumina surface to 14.5 wt. % (two grafting-pyrolysis cycles) resulted in the formation of the carbon coating with more regular graphitic structure. Розроблений новий метод хімічного дизайну вуглецевого покриття на поверхні наночастинок пірогенного Al2O3 розміром 8–10 нм. Вуглецеве покриття синтезували шляхом модифікування поверхні пірогенного оксиду алюмінію 4,4-метилендифенілдиізоціанатом та подальшим його піролізом при 700oC. З метою одержання зразків з більш високим вмістом вуглецю цикл "модифікування–піроліз" повторювали. Вищеописана процедура дозволила синтезувати зразки з вмістом вуглецю 7,6 та 14,5 % ваг. Дослідження синтезованих зразків методами раманівської та ІЧ-спектроскопії, TГ/ДTГ-ДTA, низькотемпературної адсорбції азоту та СЕM показало, що утворення суцільного вуглецевого покриття на поверхні пірогенного Al2O3 відбувається вже після проведення першого циклу "модифікування–піроліз". Повторення циклу "модифікування–піроліз" МДІ приводить до формування вуглецевого покриття з більш впорядкованою графітовою структурою. Разработан новый метод химического дизайна углеродного покрытия на поверхности наночастиц пирогенного Al2O3 размером 8–10 нм. Углеродное покрытие было синтезировано путем модифицирования поверхности пирогенного оксида алюминия 4,4–метилендифенилдиизоцианатом с последующим его пиролизом при 700oC. Для того чтобы синтезировать образцы с более высоким содержанием углерода, цикл "модифицирование–пиролиз" повторяли. Описанная выше процедура позволила синтезировать образцы с содержанием углерода 7,6 и 14,5% вес. Исследование синтезированных образцов методами рамановской и ИК-спектроскопии, TГ/ДTГ-ДTA, низкотемпературной адсорбции азота и СЭM показало, что образование сплошного углеродного покрытия на поверхности пирогенного Al2O3 происходит уже после проведения первого цикла "модифицирование–пиролиз". Повторение цикла "модифицирование–пиролиз" МДИ приводит к формированию углеродного покрытия с более упорядоченной графитовой структурой. en Інститут хімії поверхні ім. О.О. Чуйка НАН України Хімія, фізика та технологія поверхні Неорганічні та вуглецеві наноматеріали і наносистеми Chemical Design of Carbon-Coated Al2o3 Nanoparticles Хімічний дизайн вуглецевого покриття на поверхні наночастинок Al2O3 Химический дизайн углеродного покрытия на поверхности наночастиц AI2O3 Article published earlier |
| spellingShingle | Chemical Design of Carbon-Coated Al2o3 Nanoparticles Sharanda, L.F. Babich, I.V. Plyuto, Yu.V. Неорганічні та вуглецеві наноматеріали і наносистеми |
| title | Chemical Design of Carbon-Coated Al2o3 Nanoparticles |
| title_alt | Хімічний дизайн вуглецевого покриття на поверхні наночастинок Al2O3 Химический дизайн углеродного покрытия на поверхности наночастиц AI2O3 |
| title_full | Chemical Design of Carbon-Coated Al2o3 Nanoparticles |
| title_fullStr | Chemical Design of Carbon-Coated Al2o3 Nanoparticles |
| title_full_unstemmed | Chemical Design of Carbon-Coated Al2o3 Nanoparticles |
| title_short | Chemical Design of Carbon-Coated Al2o3 Nanoparticles |
| title_sort | chemical design of carbon-coated al2o3 nanoparticles |
| topic | Неорганічні та вуглецеві наноматеріали і наносистеми |
| topic_facet | Неорганічні та вуглецеві наноматеріали і наносистеми |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/29002 |
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