Гібридні композити синтезовані при карбонізації ацетилацетону та ацетилацетонатів металів на поверхні силікагелю
Hybrid adsorbents with carbon/silica, carbon/metal oxide/silica, and carbon/metal/silica could be of interest from a practical point of view since they can effectively adsorb both polar and nonpolar compounds. Therefore, mesoporous silica gel Si–60 modified by carbonization acetylacetone or Ti, Zn,...
Збережено в:
| Дата: | 2022 |
|---|---|
| Автори: | , , |
| Формат: | Стаття |
| Мова: | Англійська |
| Опубліковано: |
Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine
2022
|
| Теми: | |
| Онлайн доступ: | https://surfacezbir.com.ua/index.php/surface/article/view/753 |
| Теги: |
Додати тег
Немає тегів, Будьте першим, хто поставить тег для цього запису!
|
| Назва журналу: | Surface |
| Завантажити файл: |  |
Репозитарії
Surface| _version_ | 1869291924411645952 |
|---|---|
| author | Гунько, В. М. Скубішевська-Земба, Я. Хармас, Б. |
| author_facet | Гунько, В. М. Скубішевська-Земба, Я. Хармас, Б. |
| author_institution_txt_mv | [
{
"author": "В. М. Гунько",
"institution": "Інститут хімії поверхні ім. О.О.Чуйка Національної академії наук України"
},
{
"author": "Я. Скубішевська-Земба",
"institution": "Університет ім. Марії Кюрі-Склодовської"
},
{
"author": "Б. Хармас",
"institution": "Університет ім. Марії Кюрі-Склодовської"
}
] |
| author_sort | Гунько, В. М. |
| baseUrl_str | |
| collection | OJS |
| datestamp_date | 2023-04-20T10:24:32Z |
| description | Hybrid adsorbents with carbon/silica, carbon/metal oxide/silica, and carbon/metal/silica could be of interest from a practical point of view since they can effectively adsorb both polar and nonpolar compounds. Therefore, mesoporous silica gel Si–60 modified by carbonization acetylacetone or Ti, Zn, Ni, Co, Cr, Zr acetylacetonates has been studied using nitrogen and water adsorption–desorption, thermogravimetry, transmission electron microscopy, X–ray diffraction, and X–ray fluorescence methods. Grafted C/X phases consist of metal compounds (X denotes metal oxide or silicate or/and metal) and char, whose characteristics can be varied changing metal in the precursors and their amounts. The morphological, structural, and textural characteristics of C/X/SiO2, such as composition and particle size distributions of deposits, a number and kind of polar and non polar surface sites, specific surface area, pore volume, and pore size distributions depend on the type, content, and distribution of the C/X deposits. The changes in the grafted matters occur with increasing precursor and C/X concentrations and a possible catalytic effect of the X phases on the carbonization reactions. Appropriate selection of precursor structure and amounts allows one to vary and control the characteristics of whole hybrid adsorbents that is of importance from a practical point of view. |
| doi_str_mv | 10.15407/Surface.2022.14.159 |
| first_indexed | 2025-07-22T19:35:30Z |
| format | Article |
| fulltext |
Поверхня. 2022. Вип. 14(29). С. 159–175 159
PACS:61.43.Gt; 68.03.–g; 68.43.–h; 81.40.Ef doi: 10.15407/Surface.2022.14.159
HYBRID COMPOSITES PREPARED BY CARBONIZATION OF
ACETYLACETONE AND METAL ACETYLACETONATES ON
A SURFACE OF SILICA GEL
V.M. Gun'ko,1J.Skubiszewska-Zięba,2B. Charmas2
1Chuiko Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kyiv, Ukraine
e–mail: vlad_gunko@ukr.net
2Faculty of Chemistry, Maria Curie-Skłodowska University, 3 Maria Curie-Skłodowska Sq.,
20-031 Lublin, Poland
Hybrid adsorbents with carbon/silica, carbon/metal oxide/silica, and carbon/metal/silica
could be of interest from a practical point of view since they can effectively adsorb both polar and
nonpolar compounds. Therefore, mesoporous silica gel Si–60 modified by carbonization
acetylacetone or Ti, Zn, Ni, Co, Cr, Zr acetylacetonates has been studied using nitrogen and water
adsorption–desorption, thermogravimetry, transmission electron microscopy, X–ray diffraction,
and X–ray fluorescence methods. Grafted C/X phases consist of metal compounds (X denotes metal
oxide or silicate or/and metal) and char, whose characteristics can be varied changing metal in
the precursors and their amounts. The morphological, structural, and textural characteristics of
C/X/SiO2, such as composition and particle size distributions of deposits, a number and kind of
polar and non polar surface sites, specific surface area, pore volume, and pore size distributions
depend on the type, content, and distribution of the C/X deposits. The changes in the grafted matters
occur with increasing precursor and C/X concentrations and a possible catalytic effect of the X
phases on the carbonization reactions. Appropriate selection of precursor structure and amounts
allows one to vary and control the characteristics of whole hybrid adsorbents that is of importance
from a practical point of view.
Keywords: mesoporous silica gel, metal acetylacetonate carbonization, carbon deposits,
carbon/metal compound deposits, deposit morphology, textural characteristics, water desorption
Introduction
The adsorption characteristics of various hybrid adsorbents composed of polar and
nonpolar, hydrophilic and hydrophobic phases or surface patches at substrates could be more
appropriate for certain practical applications in comparison to simple adsorbents such as silicas [1–
12]. To prepare different hybrid adsorbents and to change their morphological, structural, textural,
and adsorption characteristics, various modification techniques can be applied to different
substrates such as silicas, porous (silica gels, precipitated silicas) or highly disperse (fumed or fuse
silicas), etc.[13–57]. One of these techniques is the carbonization of organics or more complex
precursors on the substrates that results in the formation of carbon or more complex deposits with
well controlled characteristics[4,14,36–57]. Typically, pure pyrocarbons (chars) in hybrid
adsorbents possess a relatively small number of active sites (e.g., oxidized functionalities), which
could play an important role in bonding of polar molecules in different media. This is caused by
the morphology of the carbon layers mainly of nonpolar pregraphite, turbostratic structures with
amorphized small basal planes of sizes from one to several nanometers similar to those in individual
carbon blacks, chars, and activated carbons [1–14]. To increase the amounts of active sites on
hybrid adsorbent surfaces, additional oxidizing of chars with formation of COH, C=O, COOH and
other functionalities, mixed X/SiO2 as substrates (possessing a larger number of active sites than
parent silica has [4,14]), or organometallics as C/X precursors [38,46] can be utilized. The deposit
160
structures generated upon the carbonization of organometallics could be more complex than that
of chars formed upon the carbonization of pure organics due to the formation of additional X phases
with metal oxide, silicate, or/and metal [38]. It is known that the carbonization of organometallics
on various substrates results in the formation of C/X of different structures affected not only by the
specific surface area and porosity but also by surface chemistry of the substrates[38,46]. Clearly,
the presence of carbon/metal compounds can change not only the topology and morphology but
also other characteristics of C/X/SiO2 adsorbents, such as surface site distribution, catalytic and
adsorption abilities, pore size distribution, porosity, etc. It should be noted that C/X/SiO2
adsorbents prepared using pyrolysis of organometallic precursors have not been adequately
explored in comparison to C/SiO2 materials synthesized utilizing pure organics as char precursors
[1–57]. Therefore, the aim of this work was to synthesize C/X/SiO2 materials utilizing silica gel as
a substrate modified upon the carbonization of various organometallics and to investigate the whole
adsorbents using adsorption–desorption of nitrogen and water, thermogravimetry, spectroscopic
and microscopic methods to elucidate the impact of the nature of metals in M(AcAc)n on the
morphological, structural, textural, and adsorption characteristics of whole C/X/SiO2 adsorbents.
Experimental
Materials
Mesoporous silica gel Si–60 (Merck) was used as a substrate to prepare carbon/X/silica
materials (carbosils, CSX, where X denotes a metal in the phases formed during pyrolysis of the
precursors). Silica gel Si–60 (SG) was washed away from surface mineral impurities with 18%
HCl solution in a Soxhlet apparatus and then with distilled water. Then silica gel was dried at 200
oC for 24 h and cooled in a dessicator before pyrolysis of acetylacetonates (AcAc) of zirconium
[Zr(AcAc)4], titanium [titanyl TiO(AcAc)2], nickel [Ni(AcAc)2], zinc [Zn(AcAc)2], chromium
[Cr(AcAc)3], and cobalt [Co(AcAc)2] (Aldrich) immobilized on silica gel using the impregnation
method. A given acetylacetonate (0.01 M) was deposited on 5 g of the silica gel from methanol
(250 mL) sonicated for uniform distribution of organometallics; and then methanol was removed
on degassing in vacuum.
Pyrolysis of acetylacetonates deposited on silica gel was carried out in an autoclave (0.3 dm3)
with stainless steel at 500 oC for 6 h. After the carbonization, samples were washed in the Soxhlet
apparatus with N,N–dimethylformamide and acetone to remove uncarbonized compounds, and
then dried at 200 oC in the deoxygenated nitrogen flow. The hybrid adsorbents were labeled as
CSTi, CSCr1, CSCo, CSNi, CSZn, and CSZr1 (Table 1).
Table 1. Concentrations of grafted metal compounds and char
Sample Metal
compounds
Content of metal compounds,
wt.% Structure (crystallite size)
Carbon
content,
wt.%
C = CC +
CX, wt.%
CSTi TiO2 11.37 Anatase (~11 nm) 9.2 20.57
CSCr1 Cr2O3 () 11.26 Amorphous 12.0 23.26
CSCr2 Cr2O3 (amorph.) 8.28 Amorphous 4.8 13.08
CSCo Co 8.42 Metallic Co (20–25 nm) 6.1 14.52
CSNi Ni, NiO 9.42 Ni (25 nm), NiO (~13 nm) 5.9 15.32
CSZn Zn2SiO4 10.98 Zn silicate 6.5 16.48
CSZr1 ZrO2 17.14 XRD amorphous 13.8 30.94
CSZr2 ZrO2 10.19 Partially crystalline (~4 nm) 7.4 17.59
CS1 – – – 4.0 4.0
CS2 – – – 9.1 9.1
CS3 – – – 14.5 14.5
The utilization of the same amounts (0.01 M) of metal acetylacetonates results in deposition of
equal amounts of metal moles but different amounts of moles of acetylacetonate groups, since the
n values in M(AcAc)n compounds are different (n = 2–4). Therefore, the metal valence in
161
M(AcAc)n was taken into consideration and 2/30.01 M of chromium acetylacetonate (CSCr2) and
2/40.01 M of zirconium acetylacetonate (CSZr2) were additionally utilized. Three C/silica samples
labeled as CS1, CS2, and CS3 were prepared using acetylacetone (L. Light Co.) as a precursor in
the amounts of 0.02, 0.03, and 0.04 M, respectively, per 5 g of pristine silica gel (Table 1).
Nitrogen adsorption–desorption isotherms and textural characteristics
Low–temperature (77.35 K) nitrogen adsorption–desorption isotherms were recorded using
a Sorptomat 1900 (Carlo–Erba, Milan) adsorption analyzer. The specific surface area (SBET) was
calculated using the standard BET equation [58] at p/p0 between 0.06 and 0.2 (where p and p0
denote the equilibrium and saturation pressures of nitrogen, respectively). The pore volume (Vp)
was estimated under the relative pressure p/p00.98 [59].
Fig. 1. Nitrogen adsorption-
desorption isotherms for Si-
60 and composites
The nitrogen desorption data were used to compute the pore size distributions (PSD,
differential fV(R) ~ dVp/dR and fS(R) ~ dS/dR) using a self–consistent regularization (SCR)
procedure under non–negativity condition (fV(R) 0 at any pore radius R) at a fixed regularization
parameter = 0.01. A complex pore model was applied with slit–shaped (S) pores in carbon and
cylindrical (C) pores in silica and voids (V) between spherical carbon or metallic nanoparticles
packed in random aggregates (pore models used SCV, VCV, or CV with SCR method) with the
density functional theory (DFT) method [60–62]. The differential PSD with respect to the pore
volume fV(R) ~ dV/dR, fV(R)dR ~ Vp were recalculated to incremental PSD (IPSD) at V(Ri) =
(fV(Ri+1) +fV(Ri))(Ri+1 Ri)/2 at V(Ri) = Vp. The fV(R) and fS(R) functions were also used to
calculate contributions of nanopores (Vnano and Snano at radius in the range of 0.35 nm <R 1 nm),
mesopores (Vmeso and Smeso at 1 nm <R 25 nm), and macropores (Vmacro and Smacro at 25 nm <R
100 nm) [60]. Additionally, non–local DFT method (NLDFT, Quantachrome software, with a
model of cylindrical pores in silica or slit/cylindrical pores in carbon) [63] was used to calculate
the differential PSD with respect to the pore volume and specific surface area. The average values
of the pore radii <Rx>were determined with respect to the pore volume (x = V) and specific surface
area (x = S), respectively, as the ratio of the first and zero moments of the related distribution
functions
max max
min min
( ) / ( )
R R
x x x
R R
R Rf R dR f R dR . (1)
162
XRD and XRF
XRD measurements were performed using a Siemens D 5000 powder diffractometer with Cu
K radiation in step scan mode (2step size of 0.04o, counting time of 2 s per step, 2 range of 2 –
80o). To identify the structure of synthesized deposits, the XRD patterns were compared to those
of known compounds from the JPCDS–ISDD files. Additionally, metal concentration in X phase
of C/X/SiO2 was determined using a XRF (Canberra) spectrometer with the radioactive sources of
Fe55 and Cd109. Obtained results are summarized in Table 1.
Thermogravimetric measurements
Thermal decomposition of carbon/mineral adsorbents was investigated over the 293–1273 K
range by means of thermogravimetry (TG) with differential thermal analysis (DTA) in air to
determine the carbon concentration in the composites using a Derivatograph C (Paulik,
Paulik&Erdey, MOM, Budapest) at a heating rate of 10 K/min. Thermodesorption of water was
studied under quasi–isothermal conditions. Water vapor was adsorbed on carbosils (1 g) in a
dessicator containing liquid bidistilled water at room temperature for 72 h. Wetted samples were
heated to 573 K using the TG method.
Transmission Electron Microscopy
TEM images of the samples were recorded using a BS 540 (Tesla) apparatus (accelerating
voltage 80 kV, resolution 0.8 nm, magnification 12000 or 20000). Microscope samples of C/X
were prepared using the platinum–carbon replication method with evaporation of carbon and
platinum onto the adsorbent surface then treated in hydrofluoric acid to dissolve oxides.
Results and discussion
According to XRD data (Table 1, XRD patterns are not shown here), cobalt in CSCorepresents
a metallic phase (crystallite size of 20–25 nm) due to its reduction during carbonization of
Co(AcAc)2. Nickel in CSNi is in both metallic (crystallite size 25 nm) and oxide (13 nm) phases.
CSCr contains amorphous chromium oxide. During pyrolysis of zinc acetylacetonate, zinc silicate
is formed (as well as the carbon deposits) upon the reactions between zinc compounds and silica
gel surface. CSZr2 and CSTi include zirconia (4 nm) and titania (anatase crystallites 11 nm),
respectively. The crystallite sizes were estimated using the Scherrer equation. Note that the sizes
of X crystallites are larger than the average pore size of initial Si–60 (Table 2, <RV> and <RS>);
i.e., a major portion of deposit should be formed on the outer surfaces of silica gel particles or in
broad meso/macropores visible in TEM image of initial silica gel (Figs. 2a and 3).
Table 2. Textural characteristics of unmodified and modified silica gel.
Sample SBET
m2/g
Snano
m2/g
Smeso
m2/g
Smacro
m2/g
SNLDFT
m2/g
Vp
cm3/g
Vnano
cm3/g
Vmeso
cm3/g
Vmacro,
cm3/g
<RV>
nm
<RS>
nm
Si–60 370 130 240 0 362 0.753 0.067 0.686 0 3.52 2.64
CS1 339 151 188 0.1 330 0.718 0.100 0.612 0.006 4.20 2.51
CS2 296 60 222 0 281 0.606 0.016 0.366 0.224 18.22 4.77
CS3 275 51 208 16 260 0.566 0.013 0.281 0.272 22.65 5.33
CSTi 192 48 142 2 202 0.419 0.012 0.301 0.106 24.10 4.56
CSCr1 278 125 152 1 256 0.443 0.048 0.344 0.050 8.35 2.45
CSCr2 293 76 210 7 276 0.622 0.021 0.415 0.190 17.09 4.19
CSCo 187 33 138 16 214 0.524 0.007 0.268 0.248 20.94 6.82
CSNi 263 57 196 10 258 0.566 0.013 0.347 0.206 19.07 4.82
CSZn 212 38 167 7 207 0.536 0.009 0.354 0.172 20.72 5.60
CSZr1 236 82 149 5 213 0.415 0.023 0.288 0.105 13.55 3.64
CSZr2 281 68 210 3 256 0.537 0.015 0.412 0.110 21.23 4.51
TEM images (Fig. 2) of the initial silica gel and certain carbosils confirm the location of
deposits at the outer surface (at least, partially) of silica gel globules. In silica gel globules, there
are broad mesopores and macropores (dark areas, Fig. 2a) of 30–85 nm in diameter (Fig. 3), which
163
could be considered as transport pores appropriate for location of a fraction of the deposits (Fig. 4,
Table 2). Note that the MND method with a model of cylindrical pores in silica (described in detail
elsewhere [13,60]) is sensitive to broad meso/macropores in pristine silica gel (Fig. 3) in contrast
to the DFT methods (Figs. 5a and 6a).
The carbon depositsin CS1 (Fig. 2b) consist of nanoparticles connected with adjacent ones
in aggregates. It is fairly homogenous, as only slight differences in darkening of individual areas
occupied by carbon deposits are observed. The degree of darkening of these areas depends on the
thickness of a carbon layerwith aggregated nanoparticles (the thicker the layer, the darker the area).
Some carbon particles can be also formed in broad pores (Figs. 2 and 3) as well as on the outer
surfaces of silica gel particles, and as a result, the pore volume and specific surface area of CS
decrease in comparison to the silica gel Si–60 (Table 2, V and S).
Fig. 2. TEM micrographs of (a) silica, (b) carbosil CS1, (c) CSCo, (d) CSTi, and (e) CSNi
Changes in whole adsorbent structure upon the M(AcAc)n carbonization(giving CSX) in
comparison to that of CS1 are visible in images of CSCo (Fig. 2c), CSTi (Fig. 2d), and CSNi (Fig.
2e). The features of X distribution reflect in the C/X morphology (Fig. 2), structure (Table 1), and
164
texture (Figs. 3–6, Table 2). For example, more nonuniform and denser carbon deposits are
observed for CSTi and the opposite result is for CSZn (TEM micrograph of CSZn is not shown here)
that can be caused by the difference not only in the catalytic impact of the X phase on the
carbonization reactions but also in the features of the phase distributions on the substrate. For
example, the Zn(AcAc)2 carbonization leads to the formation of a zinc–silicate phase due to the
reactions with a silica surface. The pyrolysis of TiO(AcAc)2 results in the formation of anatase
crystallites. Typically, titania deposited on a silica surface represents a segregated phase with
relatively weak contacts with a support [13]. Anatase particles (11 nm) can from on the outer
surfaces or in transport pores (Fig. 3) of silica gel particles (0.1–0.2 mm in diameter).
The nitrogen adsorption–desorption isotherms, recorded at 77.35 K (Fig. 1),demonstrate
such features as adsorption diminution in a broad range of p/p0 values that are caused by significant
changes in the porosity and specific surface area of modified silica gel samples due to any C/X
deposits. These effects depend on both CC and CX values, morphology and texture of the deposits
and whole adsorbents (Table 2, Figs. 4–6).Thus, the carbonization of acetylacetone or M(AcAc)n
is responsible for various decreases in the adsorbent porosity and accessible surface area in
comparison to the characteristics of initial silica gel (Table 2, V, S). The average pore radii(Table
2, <RV>) increase for CS samples, but changes in the <RS> values are much smaller because a
lion’s share of the specific surface area is linked to narrow pores of a much larger number than a
number of broad pores significantly contributing the pore volume.
Fig. 3. Pore size distribution for Si–60 calculated using TEM image (Fig. 2a) with ImageJ software
(granulometry plugin, ImageJ. Version 1.53u. 2022. (https://imagej.nih.gov/ij/,
https://imagej.nih.gov/ij/plugins/granulometry.html); a part of the PSD based on N2
adsorption is computed using a model cylindrical pores in silica with the MND method
[13,60] (giving 0.025, 0.681, and 0.048 cm3/g for Vnano, Vmeso, and Vmacro, respectively, and
90, 278, and 2 m2/g for Snano, Smeso, and Smacro, respectively)
165
Fig. 4. Decrease in the values of (a) SBET and (b) Vp vs. content of deposits
These morphological and textural effects could be considered as evidence of complicated
structure of particles (both of deposits and modified silica globules) and pores in C/X/SiO2, as tiny
C/X particles can be grafted in meso/macropores of silica gel, but larger C/X ones can be formed
on the outer surfaces of silica particles with partial blocking of pores (Figs. 2–6) (which can be
more effective for narrower pores), and certain changes in the silica pore walls (e.g., due to the Zn
silicate formation). Additionally, deposits have own porosity, at least, due to voids between deposit
nanoparticles Fig. 2) possessing certain surface area. As a whole, the interior porosity of deposit
nanoparticles is low since the total specific surface area of CSX decreases (Table 2, Figs. 5 and 6).
The changes in the morphology and texture of composites increase with increasing deposit content
(Fig. 4, Table 2). Note that in the case of the formation of the deposits only in pores, the V and <R>
values should decrease simultaneously and the PSD peaks should shift toward lower R values.
However, similar simple effects are not observed for any CS sample (Table 2, Figs. 5 and 6).
For CS1, CS2, and CS3, the maximal diminutions are observed for Snano and Vnano (Table
2). This effect is clearly visible for IPSD (Fig. 5a,f). There is a certain shift of the main PSD peak
of mesopores toward larger pore radius for IPSD with respect to the pore volume (Figs. 5a,f and
6a,f) and specific surface area (Figs. 5f–j and 6f–j). This can be caused by partial decomposition
(hydrolysis by water formed upon carbonization of acetylacetone) of the silica pore walls. In the
IPSDV (Fig. 5a), a peak of meso/macropores appears for CS2 and CS3. Similar peaks appear for
all CSX samples (Fig. 5a–e) with one exception for CS1 with a minimal content of carbon deposits
(Table 1). Main mesopores in silica gel globules could be linked to broad mesopores and
macropores (Fig. 3). Therefore, the pore blocking by the deposits could occur not only at the outer
surface of globules but also in the globule interior (around entrances into mesopores located in
broad meso/macropores and this process could be more effective for narrower mesopores).
Therefore, there are several tendencies in changes in the PSD shape and position of the peak of
main mesopores characteristic for the initial silica gel. The maximal shift of the main mesopore
peak toward larger pores is observed for CSZn because of the reactions of Zn(AcAc)2 with the silica
pore walls to form zinc silicate that leads to the mesopore broadening. Note that a decrease in the
SBET and Vp values vs. CX is characterized by a larger slope than that forCC (Fig. 4) because the true
density of the X phases is much greater than that of carbon.
166
Fig. 5. Incremental pore size distributions calculated using a model of cylindrical pores for SG and DFT VCV/SCR
for CS samples with respect to (a–e) the pore volume and (f–j) the specific surface area
167
Fig. 6. Differential pore size distributions calculated using the NLDFT method with a model of cylindrical pore in
silica (SiO2) and slit/cylindrical pores in carbon (C) with respect to (a–e) the pore volume and (f–j) the specific
surface area
168
This effect also suggests that the deposits partially play a role of the ballast (pure ballastas
a separate nonporous phase does not contribute the porosity and specific surface area but with no
blockingof pores). As a whole, the correct textural analysis should be based on the dependence of
the characteristics vs. onlyC = CC + CX(Fig. 4) since only pure char phase is in CS1, CS2, and
CS3 samples; i.e., it is impossible to separate the CC and CX values for CSX samples. Note that the
ballast line is located above the composite lines (Fig. 4) and its course has a smaller slope because
real deposits block the entrances into a certain part of pores and could be formed in broad pores.
Uniform blocking of pores without contribution to the porosity and specific surface area should
result in only decreasing PSD intensity without shifting peaks. However, similar results are absent
for practically all samples, only CSZr2 demonstrates the PSD changes caused mainly by pore
blocking. The PSD for CSCr1 and CSZr1 (Figs. 5 and 6) show that a fraction of the deposits is formed
in pores since there is a shift of the PSD toward smaller pore sizes (partially this could be due to
contribution of own porosity of deposits). As a whole, there is a complex picture of the changes in
the textural characteristics of the composites in a broad range of pore sizes.
Features of the C/X/SiO2 surface structures and whole texture can reflect in the adsorption–
desorption of water (Fig. 7). The increments in CC for SG CS1 CS2 CS3 are close, but
water desorption changes nonlinearly (Fig. 8a) and it is minimal for CS3 (CC> 10 wt.% is a crucial
value for the structure of carbon deposits [13]) when a marked portion of the silica surface is
covered by char and a portion of pores can be blocked by carbon particles more hydrophobic than
pristine silica surface. The main desorption occurs at 100 oC (Fig. 7) because water is weakly bound
in mesopores or unbound in broad mesopores and macropores. Significant changes in the shape of
the TG curves (Fig. 7) are observed only for CSCr1 and CSZr1 having maximal concentrations of
C/X (Table 1). A decrease in the amounts of adsorbed water correlates with a diminution of the
pore volume (Fig. 8d, fitting coefficient = 0.911) with growth of deposit filling pores. Correlation
between the amounts of desorbed water and the specific surface area is worse (Fig. 8c, = 0.652),
as the amount of desorbed water is mainly linked to the accessible pore volume.
Fig. 7. Desorption of water (TG) as a function of temperature in (a) gram of water per gram of
adsorbent and (b) gram of water per m2 of adsorbent
However, the amounts of water and other compounds desorbed upon heating to 300 oC (Fig.
7a) could be slightly smaller or larger than the pore volume (Table 3). There is no correlation
between the values of C and =d/w/Vp that can be caused by several factors:
hydrophobicity/hydrophilicity, PSD, pore length and accessibility, chemical reactions upon heating
169
to 300 oC. Physisorbed water is mainly desorbed at T< 150 oC, and the main weight loss is at 100
oC independent of the adsorbent structure. The desorption upon heating from 150 oC to 300 oC is
not great (Table 3, d300 – d150),and there is no a simple correlation of this value with the deposit
contents. Thus, the pore volume plays an important role on the adsorption/desorption of water, but
other structural and textural characteristics could affect the desorption processes that results in
certain scatter of the amounts of desorbed water vs. any textural characteristic of the adsorbents.
Table 3. Relationship between the pore volume and TG data at 300 oC.
Sample Vp
(cm3/g)
CC,
wt.%
C = CC + CX,
wt.%
Desorption
(d300) at
300oC (g/g)
=d300/w/Vp Desorption
(d150) at 150oC
(g/g)
d300– d150
(g/g)
Si–60 0.753 0 0 0.717 0.952 0.680 0.037
CS1 0.718 4.0 4.0 0.649 0.904 0.630 0.019
CS2 0.606 9.1 9.1 0.667 1.101 0.632 0.035
CS3 0.566 14.5 14.5 0.527 0.931 0.519 0.008
CSTi 0.419 9.2 20.57 0.474 1.131 0.463 0.011
CSCr1 0.443 12.0 23.26 0.439 0.991 0.342 0.097
CSCr2 0.622 4.8 13.08 0.546 0.878 0.513 0.033
CSCo 0.524 6.1 14.52 0.533 1.017 0.491 0.042
CSNi 0.566 5.9 15.32 0.534 0.943 0.522 0.012
CSZn 0.536 6.5 16.48 0.550 1.026 0.505 0.045
CSZr1 0.415 13.8 30.94 0.367 0.884 0.302 0.065
CSZr2 0.537 7.4 17.59 0.522 0.972 0.488 0.034
Note. w is the density of water.
One could assume that the char content has a stronger effect on the water adsorption than
C/X as a whole, as the angle between the line of a linear approximation Cwater(CC) and the X axis
is greater than that for Cwater(C) (Fig. 8a). However, this is rather apparent effect for CSX samples
because the X phase affects the Cwater(CC) dependence. As a whole, the water adsorption (or
desorption observed in the TG measurements, Fig. 7) practically linearly decreases with increasing
the C value causing increasing pore infilling and blocking by deposit particles. Correlation
between the deposit amounts and adsorbed/desorbed water amount per m2 of the surface area of
adsorbents is practically absent (Fig. 8b). This is due to the fact that the volume plays the main role
in the water adsorption but not the specific surface area since water adsorption occurs through the
pore volume infilling mechanism but not by the monolayer adsorption. Notice that obtained results
suggest the complicated relationships between the CC, C, V, and S values and the amounts of
adsorbed water due to nonuniformity of the changes in the C/X/SiO2surface structures and pore
size distributions both important for the water adsorption. The adsorption of water is determined
not only by the pore volume or specific surface area but also by the nature of the active surface
sites and surface fractality (roughness, small–scale nonuniformity). However, the latter is
responsible for minor effects (causing certain scatter in the related dependence, Fig. 8) but the pore
volume is the main factor determining the course of the water adsorption/desorption (Fig. 8d).
170
Fig. 8. Relationships between the amounts of desorbed water (in wt. % and mg/m2) (a, b) CC and
C= CC + CX values, (c) specific surface area, and (d) pore volume.
Conclusion
On the basis of obtained results, one can conclude that C/X depositson silica gel Si–60
affect nonlinear dependencies of the morphological and textural characteristics of whole hybrid
C/X/silica adsorbents on the C values. The simultaneous appearance of the C and X phases is
responsible for more complicated relationships between the adsorbent characteristics and deposit
amounts. It can enhance a small–scale nonuniformity of the whole surface that reflects in changes
in the pore size distribution and adsorption/desorption of water. These effects are caused by
variations in the nature (carbon, metal oxide, silicate, and metal possessing different catalytic
capabilities in pyrolysis) and structure (sizes of crystallites, amorphous oxide or silicate particles
as well as carbon ones and their distribution on silica gel substrate, in pores or on outer surface) of
C and X phases in C/X/silica gel adsorbents. There is a tendency of a reduction in the adsorbent
porosity and specific surface area with growing amounts of the C/X deposits. A correlation between
the content of the grafted phases and pore volume is closer to a linear one than that for the specific
surface area. The appearance of C or C/X deposits typically leads to broadening of the pore size
distributions. However, for some C/X/SiO2 adsorbents, then an oporosity decreases more strongly
with increasing deposit content. The largest pores are observed in the PSD for the composites
171
computed using the nitrogen adsorption with the DFT VCV/SCR method in contrast to those
computed with the NLDFT method. Grafting of C/X leads to the transformations not only of broad
meso/macropores(observed at the outer surface of initial silica globules) but also of mesopores in
the globule in terior. The deposits at the outer surface of Si-60 cause significant changes in the
average values of the pore radii <RV>. The amounts of water adsorbed onto C/X/SiO2 decrease
with increasing deposit content, and the content ofthe carbon phase (mainly hydrophobic)could
play an important role in reduction of the water adsorption than the X phase (mainly hydrophilic)
does. Therefore, there is no simple relationships between efficiency of pore infilling by water and
the total amounts of the deposits. In future, it is of interest to prepare hybrid adsorbents using a
mixture of different organometallics and substrates of different origin.
References
[1] Yang R.T. Adsorbents: Fundamentals and Applications. (New York: Wiley, 2003).
[2] Birdi K.S. (Ed.) Handbook of Surface and Colloid Chemistry. Third edition. (Boca Raton:
CRC Press, 2009).
[3] Ullmann's Encyclopedia of Industrial Chemistry. (Weinheim: Wiley–VCH, 2008).
[4] Somasundaran P. (Ed.) Encyclopedia of Surface and Colloid Science. Third Edition. (Boca
Raton: CRC Press, 2015).
[5] Ahuja S. (Ed.) Separation Science and Technology. Vol. 15. (Amsterdam: Elsevier, 2022).
[6] Hussain C.M. (Ed.) Handbook of Polymer Nanocomposites for Industrial Applications.
(Amsterdam: Elsevier, 2021).
[7] Ahmad A., Kumar R., Jawaid M. (Eds.) Emerging Techniques for Treatment of Toxic
Metals from Wastewater. (Amsterdam: Elsevier, 2022).
[8] S. Singh, P. Kumar, D.P. Mondal (Eds.) Advanced Ceramics for Versatile Interdisciplinary
Applications. (Amsterdam: Elsevier, 2022).
[9] Ngu L.H. Carbon Capture Technologies. (Amsterdam: Elsevier, 2022).
[10] Lu K. Nanoparticulate Materials. Synthesis, Characterization, and Processing. (Hoboken,
New Jersey: John Wiley & Sons, Inc., 2013).
[11] Moreno–Piraján J.C., Giraldo–Gutierrez L., Gómez–Granados F. Porous Materials Theory
and Its Application for Environmental Remediation. (Cham: Springer Nature, 2021).
[12] Rousseau R.W. Handbook of Separation Process Technology. (New York: John Wiley &
Sons, 1987).
[13] Gun’ko V.M., Turov V.V. Nuclear Magnetic Resonance Studies of Interfacial Phenomena.
(Boca Raton: CRC Press, 2013).
[14] Leboda R. Carbon–mineral adsorbents – new type of sorbents. Part I. The methods of
preparation. Mater. Chem. Phys. 1992. 31: 243. Part II. Surface properties and methods of
their modification Mater. Chem. Phys. 1993. 34: 123.
[15] Chan Z., Miao F., Xiao Z., Juan H., Hongbing Z. Effect of doping levels on the pore
structure of carbon nanotube/silica xerogel composites. Mater. Lett.2007. 61: 644.
[16] Lavorgna M., Romeo V., Martone A., Zarrelli M., Giordano M., Buonocore G.G., Qu M.Z.,
Fei G.X., Xia H.S. Silanization and silica enrichment of multiwalled carbon nanotubes:
Synergistic effects on the thermal–mechanical properties of epoxy nanocomposites.
European Polymer J.2013. 49: 428.
[17] Othman R.N., Kinloch I.A., Wilkinson A.N. Synthesis and characterisation of silica–carbon
nanotube hybrid microparticles and their effect on the electrical properties of poly(vinyl
alcohol) composites. Carbon.2013. 60: 461.
[18] Choi S., Kim K., Nam J., Shim S.E. Synthesis of silica–coated graphite by enolization of
poly vinyl pyrrolidone and its thermal and electrical conductivity in polymer composites.
Carbon.2013. 60: 254.
172
[19] Chu Y.–H., Yamagishi M., Wang Z.–M., Kanoh H., Hirotsu T. Adsorption characteristics
of nanoporous carbon–silica composites synthesized from graphite oxide by a
mechanochemical intercalation method. J. Colloid Interface Sci.2007. 312: 186.
[20] Wang Z.–M., Shishibori K., Hoshinoo K., Kanoh H., Hirotsu T. Examination of synthesis
conditions for graphite–derived nanoporous carbon–silica composites. Carbon.2006. 44:
2479.
[21] Kumagai S., Ishizawa H., Aoki Y., Toida Y. Molded micro– and mesoporous carbon/silica
composite from rice husk and beet sugar. Chem. Eng. J. 2010. 156: 270.
[22] Tso C.Y., Chao C.Y.H. Activated carbon, silica–gel and calcium chloride composite
adsorbents for energy efficient solar adsorption cooling and dehumidification systems. Int. J.
Refrigeration. 2012. 35: 1626.
[23] Ye L., Ji Z.–H., Han W.–J., Hu J.–D., Zhao T. Synthesis and characterization of silica/carbon
composite aerogels. J. Am. Ceramic Soc. 2010. 93: 1156.
[24] Furtado A.M.B., Wang Y., LeVan M.D. Carbon silica composites for sulfur dioxide and
ammonia adsorption. Micropor. Mesopor. Mater. 2013. 165: 48.
[25] Glover T.G., LeVan M.D. Carbon–silica composite adsorbent: Sensitivity to synthesis
conditions. Micropor. Mesopor. Mater. 2009. 118: 21.
[26] Valle–Vigón P., Sevilla M., Fuertes A.B. Carboxyl–functionalized mesoporous silica–
carbon composites as highly efficient adsorbents in liquid phase. Micropor. Mesopor.
Mater. 2013. 176: 78.
[27] Santa C.F., Jaber M., Guth J.L., Sierra L. Synthesis of texturally biphasic mesoporous
carbon–silica composites and carbons. Micropor. Mesopor. Mater. 2013. 173: 53.
[28] Lua A.C., Shen Y. Preparation and characterization of polyimide–silica composite
membranes and their derived carbon–silica composite membranes for gas separation. Chem.
Eng. J. 2013. 220: 441.
[29] Sanchez F., Ince C. Microstructure and macroscopic properties of hybrid carbon
nanofiber/silica fume cement composites. Compos. Sci. Technol. 2009. 69: 1310.
[30] Zhou X., Shi T. One–pot hydrothermal synthesis of a mesoporous SiO2–graphene hybrid
with tunable surface area and pore size. Appl. Surf. Sci. 2012. 259: 566.
[31] Nandan D., Sreenivasulu P., Sivakumar Konathala L.N., Kumar M., Viswanadham N. Acid
functionalized carbon–silica composite and its application for solketal production.
Micropor. Mesopor. Mater. 2013. 179: 182.
[32] Xu H., Zhang H., Huang Y., Wang Y. Porous carbon/silica composite monoliths derived
from resorcinol–formaldehyde/TEOS. J. Non–Crystal. Solid. 2010. 356: 971.
[33] Charmas B. Characterization of porosity and thermal properties of Ni–doped carbosils
obtained by starch gelation. Adsorption Science & Technology. 2015. 33: 539.
[34] Meti P., Mahadik D.B., Lee K.–Y., Wang Q., Kanamori K., Gong Y.–D., Park H.–H.
Overview of organic–inorganic hybrid silica aerogels: Progress and perspectives. Materials
& Design. 2022. 222: 111091.
[35] Ounphikul B., Chantarasombat N., Hunt A.J., Ngernyen Y. A new low–cost carbon–silica
composite adsorbent from a by–product of the sugar industry. Materials Today: Proc. 2022.
51: 1884.
[36] Gun’ko V.M., Matkovsky A.K., Charmas B., Skubiszewska–Zięba J., Pasieczna–
Patkowska S., Carbon–silica gel adsorbents: effects of matrix structure and carbon content
on adsorption of polar and nonpolar adsorbates. J. Thermal Analysis and Calorimetry.
2017, 128: 1683.
[37] Leboda R., Turov V.V., Charmas B., Skubiszewska–Zięba J., Gun'ko V.M. Surface
properties of mesoporous carbon–silica gel adsorbents. J. Colloid Interface Sci. 2000. 223:
112.
173
[38] Gun’ko V.M., Leboda R., Skubiszewska–Zięba J., Rynkowski J. Silica gel modified due to
pyrolysis of acetylacetone or metal (Ti, Cr, Co, Ni, Zn, Zr) acetylacetonates. J. Colloid
Interface Sci. 2000. 231: 13.
[39] Gun’ko V.M., Leboda R., Turov V.V., Villiéras F., Skubiszewska–Zięba J., Chodorowski S.,
Marciniak M. Structural and energetic nonuniformities of pyrocarbon–mineral adsorbents. J.
Colloid Interface Sci. 2001. 238: 340.
[40] Gun’ko V.M., Leboda R., Skubiszewska–Zięba J., Turov V.V., Kowalczyk P. Structure of
silica gel Si–60 and pyrocarbon/silica gel adsorbents thermally and hydrothermally treated.
Langmuir. 2001. 17: 3148.
[41] Gun’ko V.M., Leboda R., Pokrovskiy V.A., Charmas B., Turov V.V., Ryczkowski J. A
study of the organic carbon content of silica gel carbonised by pyrolysis of alcohols. J.
AnalyticalAppliedPyrolysis. 2001. 60: 233.
[42] Skubiszewska–Zięba J., Leboda R., Seledets O., Gun’ko V.M. Effect of preparation
conditions of carbon–silica adsorbents based on mesoporous silica gel Si–100 and
carbonised glucose on their pore structure. Colloids Surf. A: Physicochem. Eng. Aspects.
2003. 231: 39.
[43] Gun’ko V.M., Skubiszewska–Zięba J., Leboda R., Turov V.V. Impact of thermal and
hydrothermal treatments on structural characteristics of silica Gel Si–40 and carbon/silica gel
adsorbents. Colloids Surf. A: Physicochem. Eng. Aspects. 2004. 235: 101.
[44] Seledets O., Gun’ko V.M., Skubiszewska–Zięba J., Leboda R., Musiatowicz M.,
Podkoscielny P., Dabrowski A. Structural and energetic heterogeneities of
pyrocarbon/silica gel systems and their adsorption properties. Appl. Surf. Sci. 2005. 240:
222.
[45] Gun’ko V.M., Seledets O., Skubiszewska–Zięba J., Zarko V.I., Leboda R., Janusz W.,
Chibowski S. Phosphorus–containing carbon deposits on silica gel Si–100. Micropor.
Mesopor. Mater. 2005.87: 133.
[46] BlitzJ.P., Gun'koV.M. (Eds.)Surface Chemistry in Biomedical and Environmental
Science.NATO Science Series II: Mathematics, Physics and Chemistry. Vol. 228
(Dordrecht: Springer,2006).
[47] Skubiszewska–Zięba J., Charmas B., Leboda R., Gun’ko V.M. Carbon–mineral adsorbents
with a diatomaceous earth/perlite matrix modified by carbon deposits. Micropor. Mesopor.
Mater. 2012. 156: 209.
[48] Tomaszewski W., Gun’ko V.M.,Skubiszewska–Zięba J., Charmas B., Leboda R. Influence
of carbon deposits and subsequent silylation of silica gel on sorption efficiency of explosive
nitramines. ColloidsSurf. A: Physicochem. Eng. Aspects. 2015. 468: 76.
[49] Tomaszewski W., Gun’ko V.M. Evaluation of adsorption and desorption steps in solid–
phase extraction of explosives using carbon/silica gel nanocomposites. J. Separ. Sci. 2015.
38: 2488.
[50] Leboda R., Marciniak M., Gun’ko V.M., Grzegorczyk W., Malygin A.A.,Malkov A.A.
Structure of carbonized mesoporous silica gel/ CVD–titania.Colloids Surf. A: Physicochem.
Eng. Aspects. 2000.167: 275.
[51] Gun'ko V.M., Leboda R., Marciniak M., Grzegorczyk W., Skubiszewska–Zięba J.,Malygin
A.A.,Malkov A.A. CVD–titania/silica gel carbonized due to pyrolysis of
cyclohexene.Langmuir. 2000.16: 3227.
[52] Gun’ko V.M., Leboda R., Charmas B., Villieras F. Characterization of spatial and energetic
structures of carbon–silica gels.Colloids Surf. A: Physicochem. Eng. Aspects. 2000.173: 159.
[53] Gun’ko V.M., Villiéras F., Leboda R., Marciniak M., Charmas B., Skubiszewska–Zięba J.,
Characterization of CVD–titania/silica gel by means of low pressure nitrogen adsorption.J.
Colloid Interface Sci. 2000.230: 320.
174
[54] Leboda R., Gun’ko V.M., Skubiszewska–Zięba J., Gierak A., Oleszczuk P. Properties of thin
polythylene glycol layers on the surface of silica gel and pyrocarbon/silica gel. Effect of
topography and morphology of carbon deposit.Mater. Chem. Phys. 2001.70: 25.
[55] Gun’ko V.M., Leboda R., Turov V.V., Charmas B., Skubiszewska–Zięba J. Structural and
energetic heterogeneities of hybrid carbon–mineral adsorbents. Appl. Surf. Sci. 2002. 191:
286.
[56] Gun’ko V.M., Turov V.V., Skubiszewska–Zięba J., Charmas B., Leboda R. Structural and
adsorptive characteristics of pyrocabon/silica gel Si–60.Adsorption. 2004.10: 5.
[57] Gun’ko V.M. Confined space effects on various liquids interacting with fumed nanooxides
and porous silicas.Chem. Phys. Technol. Surf. 2022. 13: 47.
[58] Gregg S.J., Sing K.S.W. Adsorption, Surface Area and Porosity. 2nd ed. (London: Academic
Press, 1982).
[59] Adamson A.W., Gast A.P. Physical Chemistry of Surface. 6th edition. (New York: Wiley, 1997).
[60] Gun’ko V.M. Textural characteristics of composite adsorbents analyzed with density
functional theory and self–consistent regularization procedure. Chemistry, Physics and
Technology of Surface. 2020. 11: 163.
[61] Gun’ko V.M. Various methods to describe the morphological and textural characteristics of
various materials. Chemistry, Physics and Technology of Surface. 2018. 9: 317.
[62] Gun’ko V.M. Morphological and textural features of various materials composed of porous
or nonporous nanoparticles differently packed in secondary structures. Appl. Surf. Sci.
2021. 569: 151117.
[63] Ravikovitch P.I., Neimark A.V. Density functional theory model of adsorption on
amorphous and microporous silica materials. Langmuir. 2006. 22: 11171.
175
ГІБРИДНІ КОМПОЗИТИ СИНТЕЗОВАНІ ПРИ
КАРБОНІЗАЦІЇ АЦЕТИЛАЦЕТОНУ ТА
АЦЕТИЛАЦЕТОНАТІВ МЕТАЛІВ НА ПОВЕРХНІ
СИЛІКАГЕЛЮ
В.М. Гунько1, Я. Скубішевська-Земба2, Б. Хармас2
1Інститут хімії поверхні ім. О.О. Чуйка Національної академії наук України
вул. Генерала Наумова, 17, Київ, 03164, Україна, e-mail:vlad_gunko@ukr.net
2Хімічний факультет, Університет ім. Марії Кюрі-Склодовської, пл. Марії Кюрі-
Склодовської, 3, 20-031Люблін, Польща
Гібридні адсорбенти з вуглецем/кремнеземом, вуглецем/оксидом
металу/кремнеземом і вуглецем/металом/кремнеземом можуть бути цікаві з практичної
точки зору, оскільки вони можуть ефективно адсорбувати як полярні, так і неполярні
сполуки. Тому мезопористий силікагель Si–60, модифікований карбонізацією
ацетилацетону або ацетилацетонатів цирконію, титану, нікелю, цинку, хрому та
кобальту досліджували за допомогою адсорбції-десорбції азоту та води,
термогравіметрії, трансмісійної електронної мікроскопії, рентгенівської дифракції та
рентгенівської флуоресценції. Прищеплені фази C/X складаються із сполук металу (X
позначає оксид або силікат металу або метал) і вугілля, характеристики яких можна
змінювати, змінюючи метал у прекурсорах та їхню кількість при карбонізації.
Морфологічні, структурні та текстурні характеристики C/X/SiO2, такі як склад і розподіл
частинок за розміром депозитів, число та сорт полярних та неполярних поверхневих
центрів, питома поверхня, об’єм пор та розподіл пор за розмірами залежать від типу і
вмісту депозитів C/X. Зміни в прищеплених речовинах відбуваються зі збільшенням
концентрації прекурсору та C/X та можливого каталітичного ефекту X-фаз на
карбонізацію. Правильний підбір структури та кількості прекурсорів дозволяє
контролювати характеристики гібридних адсорбентів, що важливо з практичної точки
зору.
Ключові слова:мезопористийсилікагель, карбонізація ацетилацетонатів металів, вуглецеві
депозити, депозити вуглець/сполука металу, морфологія депозитів, текстурні
характеристики, десорбція води
|
| id | oai:ojs.pkp.sfu.ca:article-753 |
| institution | Surface |
| keywords_txt_mv | keywords |
| language | English |
| last_indexed | 2025-09-24T17:45:58Z |
| publishDate | 2022 |
| publisher | Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine |
| record_format | ojs |
| resource_txt_mv | surfacezbircomua/34/c0776691d82ce9060f410df1da0b1434.pdf |
| spelling | oai:ojs.pkp.sfu.ca:article-7532023-04-20T10:24:32Z Hybrid composites prepared by carbonization of acetylacetone and metal acetylacetonates on a surface of silica gel Гібридні композити синтезовані при карбонізації ацетилацетону та ацетилацетонатів металів на поверхні силікагелю Гунько, В. М. Скубішевська-Земба, Я. Хармас, Б. mesoporous silica gel metal acetylacetonate carbonization carbon deposits carbon/metal compound deposits deposit morphology textural characteristics water desorption мезопористий силікагель карбонізація ацетилацетонатів металів вуглецеві депозити депозити вуглець/сполука металу морфологія депозитів текстурні характеристики десорбція води Hybrid adsorbents with carbon/silica, carbon/metal oxide/silica, and carbon/metal/silica could be of interest from a practical point of view since they can effectively adsorb both polar and nonpolar compounds. Therefore, mesoporous silica gel Si–60 modified by carbonization acetylacetone or Ti, Zn, Ni, Co, Cr, Zr acetylacetonates has been studied using nitrogen and water adsorption–desorption, thermogravimetry, transmission electron microscopy, X–ray diffraction, and X–ray fluorescence methods. Grafted C/X phases consist of metal compounds (X denotes metal oxide or silicate or/and metal) and char, whose characteristics can be varied changing metal in the precursors and their amounts. The morphological, structural, and textural characteristics of C/X/SiO2, such as composition and particle size distributions of deposits, a number and kind of polar and non polar surface sites, specific surface area, pore volume, and pore size distributions depend on the type, content, and distribution of the C/X deposits. The changes in the grafted matters occur with increasing precursor and C/X concentrations and a possible catalytic effect of the X phases on the carbonization reactions. Appropriate selection of precursor structure and amounts allows one to vary and control the characteristics of whole hybrid adsorbents that is of importance from a practical point of view. Гібридні адсорбенти з вуглецем/кремнеземом, вуглецем/оксидом металу/кремнеземом і вуглецем/металом/кремнеземом можуть бути цікаві з практичної точки зору, оскільки вони можуть ефективно адсорбувати як полярні, так і неполярні сполуки. Тому мезопористий силікагель Si–60, модифікований карбонізацією ацетилацетону або ацетилацетонатів цирконію, титану, нікелю, цинку, хрому та кобальту досліджували за допомогою адсорбції-десорбції азоту та води, термогравіметрії, трансмісійної електронної мікроскопії, рентгенівської дифракції та рентгенівської флуоресценції. Прищеплені фази C/X складаються із сполук металу (X позначає оксид або силікат металу або метал) і вугілля, характеристики яких можна змінювати, змінюючи метал у прекурсорах та їхню кількість при карбонізації. Морфологічні, структурні та текстурні характеристики C/X/SiO2, такі як склад і розподіл частинок за розміром депозитів, число та сорт полярних та неполярних поверхневих центрів, питома поверхня, об’єм пор та розподіл пор за розмірами залежать від типу і вмісту депозитів C/X. Зміни в прищеплених речовинах відбуваються зі збільшенням концентрації прекурсору та C/X та можливого каталітичного ефекту X-фаз на карбонізацію. Правильний підбір структури та кількості прекурсорів дозволяє контролювати характеристики гібридних адсорбентів, що важливо з практичної точки зору. Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine 2022-11-30 Article Article application/pdf https://surfacezbir.com.ua/index.php/surface/article/view/753 10.15407/Surface.2022.14.159 Surface; No. 14(29) (2022): Surface; 159-175 Поверхность; № 14(29) (2022): Поверхня; 159-175 Поверхня; № 14(29) (2022): Поверхня; 159-175 3154-8091 3154-8083 10.15407/Surface.2022.14 en https://surfacezbir.com.ua/index.php/surface/article/view/753/747 Авторське право (c) 2022 В.М. Гунько, Я. Скубішевська-Земба, Б. Хармас |
| spellingShingle | мезопористий силікагель карбонізація ацетилацетонатів металів вуглецеві депозити депозити вуглець/сполука металу морфологія депозитів текстурні характеристики десорбція води Гунько, В. М. Скубішевська-Земба, Я. Хармас, Б. Гібридні композити синтезовані при карбонізації ацетилацетону та ацетилацетонатів металів на поверхні силікагелю |
| title | Гібридні композити синтезовані при карбонізації ацетилацетону та ацетилацетонатів металів на поверхні силікагелю |
| title_alt | Hybrid composites prepared by carbonization of acetylacetone and metal acetylacetonates on a surface of silica gel |
| title_full | Гібридні композити синтезовані при карбонізації ацетилацетону та ацетилацетонатів металів на поверхні силікагелю |
| title_fullStr | Гібридні композити синтезовані при карбонізації ацетилацетону та ацетилацетонатів металів на поверхні силікагелю |
| title_full_unstemmed | Гібридні композити синтезовані при карбонізації ацетилацетону та ацетилацетонатів металів на поверхні силікагелю |
| title_short | Гібридні композити синтезовані при карбонізації ацетилацетону та ацетилацетонатів металів на поверхні силікагелю |
| title_sort | гібридні композити синтезовані при карбонізації ацетилацетону та ацетилацетонатів металів на поверхні силікагелю |
| topic | мезопористий силікагель карбонізація ацетилацетонатів металів вуглецеві депозити депозити вуглець/сполука металу морфологія депозитів текстурні характеристики десорбція води |
| topic_facet | mesoporous silica gel metal acetylacetonate carbonization carbon deposits carbon/metal compound deposits deposit morphology textural characteristics water desorption мезопористий силікагель карбонізація ацетилацетонатів металів вуглецеві депозити депозити вуглець/сполука металу морфологія депозитів текстурні характеристики десорбція води |
| url | https://surfacezbir.com.ua/index.php/surface/article/view/753 |
| work_keys_str_mv | AT gunʹkovm hybridcompositespreparedbycarbonizationofacetylacetoneandmetalacetylacetonatesonasurfaceofsilicagel AT skubíševsʹkazembaâ hybridcompositespreparedbycarbonizationofacetylacetoneandmetalacetylacetonatesonasurfaceofsilicagel AT harmasb hybridcompositespreparedbycarbonizationofacetylacetoneandmetalacetylacetonatesonasurfaceofsilicagel AT gunʹkovm gíbridníkompozitisintezovaníprikarbonízacííacetilacetonutaacetilacetonatívmetalívnapoverhnísilíkagelû AT skubíševsʹkazembaâ gíbridníkompozitisintezovaníprikarbonízacííacetilacetonutaacetilacetonatívmetalívnapoverhnísilíkagelû AT harmasb gíbridníkompozitisintezovaníprikarbonízacííacetilacetonutaacetilacetonatívmetalívnapoverhnísilíkagelû |