Title 1.
Research of new reception methods of hydrogen hydrates by freezing hydrogen
emulsion with use as surface-active substances an organical silica
(by emulsion of hydrogen in the water environment and the subsequent freezing a gas
emulsion at temperature 5-30оС)
1.
I.F. Mironyuk; V.V. Lobanov; V.M. Ogenko. Electrostatic Potential and Adsorption
Characteristics of the Trimethyl-Silylated Surface of Silica // Theoretical and Experimental
Chemistry, v.36, #5, 2000, pp. 264-267.
The distribution of electrostatic potential in the vicinity of the hydroxylated and trimethylsilylated
surface of silica was calculated in the semiempirical PM3 approximation. A new mechanism is
proposed for the bonding of electron-donating molecules with the surface of hydrophobized silicas.
http://www.springerlink.com/content/pq71453q387r7736/
2.
I.F. Mironyuk; V.V. Lobanov; V.M. Ogenko. Hydrophobic and Hydrophilic Properties of
Partially Trimethylsilylated Silica Surface // Physics and Chemistry of Solid State, v.1, #2,
2000, pp. 177-184.
Hydrophobic and hydrophilic properties of partially trimethylsilylated silica have been analyzed in
terms of near-surface distribution of molecular electrostatic potential. The initial stages of silylating
have been shown to cause some growth in surface hydrophility. The following occupation of the
surface by trimethylsilylic groups results in more and more increase of its hydrophobicy. In the
subsurface layer of the totally trimethylsilylated silica there are only small compact regions of
negative potential values that provide its slight proton acceptor capability.
http://www.pu.if.ua/inst/phys_che/start/pcss/vol1/0102-03.pdf
3.
I.F. Mironyuk; V.V. Lobanov; V.M. Ogenko. Energetics of Consistent Sililation Reactions
of Silica Surface // Ukrainian Chemistry Journal, v.66, #12, 2000, p. 91-94.
4.
Gun'ko V.M., Mironyuk I.F., Zarko V.I., Turov V.V., Voronin E.F., Pakhlov E.M.,
Goncharuk E.V., Leboda R., Scubiszewska-Zieba J., Janusz W., Chibowski S., Levchuk
Yu.N. and Klyueva A.V. Fumed Silicas Possessing Different Morphology and
Hydrophilicity // Journal of Colloid and Interface Science, Volume 242, Issue 1, 1 October
2001, Pages 90-103.
Fumed silicas synthesized under varied conditions (stoichiometric or nonstoichiometric amounts of
reactants SiCl4, O2 (mixed with N2), and H2, different burner diameter, flow velocity and turbulence,
flame temperature, etc.) were studied using adsorption of nitrogen, argon, and water, infrared (IR)
and photon correlation spectroscopy, 1H NMR, and electrokinetic methods. Prepared silicas posses
different specific surface area (SAr=85–512 m2/g), structures of primary particles and their swarms,
concentrations of silanols (COH=1.9–5.2 μmol/m2), and weakly (Cw,105=0.4–2.4 wt%) and strongly
(Cw,900=0.4–2.2 wt%) bound waters. There is correlation between the specific surface area (S) of
fumed silica and the flow velocity vf(S ln vf at vf<25–30 m/s). A decrease in the amounts of
hydrogen/oxygen in the flame and elevating synthesis temperature or flame turbulence (due to an
increase in the burner diameter or changes in the reactant amounts) enhances the size of primary
particles, which become slightly micropous on addition of hydrogen (though an annular nozzle)
reacting at the flame periphery. Dividing of the flow in the burner to several smaller flows reducing
the turbulence without changes in other synthesis conditions significantly enhances the specific
surface area. The concentration of silanols increases with growing primary particle size, and the
hydrophilicity (Cw,105+Cw,900) decreases at oxygen deficiency on the synthesis.
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WHR-45B63PX3X&_user=10&_coverDate=10%2F01%2F2001&_alid=1048560818&_rdoc=2&_fmt=high&_orig
=search&_cdi=6857&_sort=r&_docanchor=&view=c&_ct=4&_acct=C000050221&_version=1&
_urlVersion=0&_userid=10&md5=a17b7240dbebd895139076ea4ee652e0
5.
Mironyuk I.F., Gun’ko V.M., Turov V.V., Zarko V.I., Leboda R. аnd Skudiszewska-Zieba J.
Characterization of Fumed Silicas and their Interaction with Water and Dissolued Proteins //
Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 180, Issues 12, 15 May 2001, Pages 87-101.
Fumed silicas synthesised with varied amounts of reactants (SiCl4, O2, H2) at the flame
temperature of 1100–1400°C were studied using adsorption, infrared (IR), 1H NMR,
dielectric relaxation (DRS) and photon correlation spectroscopy methods. These samples
possess different specific surface area (100–410 m2 g−1), concentration of silanols (2.4–4.8
μmol m−2), weakly (0.6–3.0.wt.%) and strongly (0.5–3.8 wt.%) bound water (in air).
Elevating synthesis temperature and decrease in the amounts of hydrogen/oxygen in the
flame reduce the size of primary particles and the hydration level of fumed silica surfaces.
Changes in synthetic conditions impact the characteristics not only of silica powders
(reflected in their IR, DRS and NMR spectra in air) but also of their aqueous suspensions
and adsorption of dissolved polymers such as albumin and gelatin. Increase in the
concentration of surface silanols with growing size of primary particles enhances protein
adsorption in mg m−2 of the oxide surface.
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFR-424M29RB&_user=10&_coverDate=05%2F15%2F2001&_alid=1048574834&_rdoc=3&_fmt=high&_orig=s
earch&_cdi=5233&_sort=r&_docanchor=&view=c&_ct=4&_acct=C000050221&_version=1&_url
Version=0&_userid=10&md5=8a3fc98afa3ec0b87df8d4637c254e52
6.
I.F. Myronyuk, V.V. Lobanov V. M. Ogenko, A.A. Chuiko. Composition, Properties and
Structure of Silica Hydrophobic Surface // Surface Chemistry of Silica.: into 2 parts / Edit.
academician of NAS of Ukraine A.A. Chuiko. K., 2001, p.1, pp. 113-147.
The monograph deals with generalized results of the major works from scientific legacy of A.A.
Chuiko in the field of surface chemistry of dispersed silica and a great amount of literature data in
these problems. The authors consideret in detail the structure and properties of crystalline and
amorphous modifications of SiO2, the basic methods of synthesis of its most wide-spread disperse
forms, structure of their surface as well as of hydroxyl and hydrate cover, nature of the adsorption
sites, mechanism of adsorption and chemisorption of polar molecules; they described a great
number of the reactions of chemical modifying silica surfaces. Basing on the approach to the
consideration of element transformations in the surface layers of oxides developed by the authors, a
great amount of experimental data had been analyzed from the single positions; a consistent account
of proceeding regularities was proposed and reaction mechanisms on SiO2 surface had been
interpreted.
Intended for students, post-graduated, professors and researchers specialized in chemistry, physics,
and technology of solids, adsorption, heterogenous catalysis, chromatography, as well as for
engineers and technologists of production of materials for adsorption and catalysis.
7.
Gun'ko V.M., Scubiszewska-Zieba J., Leboda R., Khomenko K.N., Kazakova O.A.,
Povazhnyak M.O., and Mironyuk I.F. Influence of Morphology and Composition of Fumed
Oxides on Changes in Their Structural and Adsorptive Characteristics on Hydrothermal
Treatment at Different Temperatures, // Journal of Colloid and Interface Science, Volume
269, Issue 2, 15 January 2004, Pages 403-424.
A series of fumed oxides such as silica, titania, alumina, silica/alumina (SA), silica/titania (ST), and
alumina/silica/titania (AST), initial and hydrothermally treated (HTT) in the steam phase at
THTT=150, 250, and 350 °C was studied by adsorption, AFM, XRD, FTIR, and theoretical methods.
Diminution of the size of primary particles (corresponding to increasing SBET) of initial silica and
mixed oxides results in enhancement of their structural changes on HTT with elevating THTT and
increasing density of packing of primary particles in the secondary structures. Relative changes in
the texture of treated fumed silicas are smaller than those of mesoporous silica gels occurring under
similar HTT conditions. On HTT, aggregates of primary particles and their agglomerates become
denser but their surface layers become looser because of transfer of silica fragments from one
particle to another, and the smaller the initial primary particles, the greater the relative diminution
of the specific surface area SBET for the same type of primary particle packing in aggregates.
Relative changes in the pore volume Vp (or VBJHd) on HTT are more complex than that of SBET, as for
many samples the Vp value increases especially at THTT=150 °C. Alumina and titania partially inhibit
structural changes on HTT, which decrease in the series silica > SA > AST ≈ ST.
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WHR-49HDPY68&_user=10&_coverDate=01%2F15%2F2004&_alid=1048560818&_rdoc=3&_fmt=high&_orig
=search&_cdi=6857&_sort=r&_docanchor=&view=c&_ct=4&_acct=C000050221&_version=1&
_urlVersion=0&_userid=10&md5=cd7c4f1f634e53c08ad944619226b1bd
8.
Gun'ko V.M., Zarko V.I., Mironyuk I.F., Goncharuk E.V., Guzenko N.V., Borysenko M.V.,
Janusz W., Leboda R., Scubiszewska-Zieba J., Gregorczyk W., Charmas B., Matysek M.
and Chibowski S. Surface electric and titration behavior of fumed oxides // Colloids and
Surfaces A: Physicochemical and Engineering Aspects, Volume 240, Issues 1-3, 15 June
2004, Pages 9-25.
Adsorption of Pb(II), Sr(II), and Cs(I) on fumed silica, alumina, titania, silica/titania (ST),
silica/alumina (SA), and alumina/silica/titania (AST) reveals that mixed oxides containing titania
have a greater adsorptive capability in respect to metal cations than individual and SA oxides.
Pyrocarbon deposits on fumed oxides enhance the adsorption of metal ions. Calculations of
electrophoretic potential (ζ) with consideration for the porosity of aggregates of primary particles of
AST show a significant influence of surface alumina (at pH<8) and titania and silica (at pH>8) on
the ζ values. The effective diameter of particles (Def) of fumed oxides in aqueous media depends on
pH for AST stronger than for ST (between isoelectric points (IEPs) of titania and alumina). A
significant difference in the pH values of IEP and point of zero charge is observed for AST samples.
A pyrocarbon influence on the ζ potential depends on the type of oxide matrix, since ζ increases for
certain samples but for others it decreases. These changes depend nonlinearly on pH as well as the
secondary particle size distributions (SPSDs) and Def.
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFR-4CBW5YC2&_user=10&_coverDate=06%2F15%2F2004&_alid=1048574834&_rdoc=1&_fmt=high&_orig
=search&_cdi=5233&_sort=r&_docanchor=&view=c&_ct=4&_acct=C000050221&_version=1&
_urlVersion=0&_userid=10&md5=27383221afe49dd157fb99c6cbf5278d
9.
V.M. Gun’ko, I.F. Mironyuk, V.I. Zarko, E.F. Voronin, V.V. Turow, E.M. Pakhlow,
E.V. Goncharuk,
Y.M. Niciporuk,
N.N. Vlasova, P.P. Gorbik,
O.A. Mishchuk,
A.A. Chuiko, T.V. Kulik, B.B. Palyanytsya, S.V. Pakhovchishin, J. Skubiszewska-Zięba,
W. Janusz, A.V. Turov, R. Leboda. Morphology and surface properties of fumed silicas //
Journal of Colloid and Interface Science, Volume 289, Issue 2, 15 September 2005, Pages
427-445.
Several series of fumed silicas and mixed fumed oxides produced and treated under different
conditions were studied in gaseous and liquid media using nitrogen and water adsorption–
desorption, mass spectrometry, FTIR, NMR, thermally stimulated depolarization current (TSDC),
photon correlation spectroscopy (PCS), zeta potential, potentiometric titration, and Auger electron
spectroscopy methods. Aggregation of primary particles and adsorption capacity (Vp) decrease and
hysteresis loops of nitrogen adsorption–desorption isotherms becomes shorter with decreasing
specific surface area (SBET). However, the shape of nitrogen adsorption–desorption isotherms can be
assigned to the same type independent of SBET value. The main maximum of pore size distribution
(gaps between primary nonporous particles in aggregates and agglomerates) shifts toward larger
pore size and its intensity decreases with decreasing SBET value. The water adsorption increases with
increasing SBET value; however, the opposite effect is observed for the content of surface hydroxyls
(in mmol/m2). Associative desorption of water (2( Si OH) → Si O Si + H2O) depends
on both the morphology and synthesis conditions of fumed silica. The silica dissolution rate
increases with increasing SBET and pH values. However, surface charge density and the modulus of
zeta-potential increase with decreasing SBET value. The PCS, 1H NMR, and TSDC spectra
demonstrate rearrangement of the fumed silica dispersion depending on the SBET value and the silica
concentration (CSiO2) in the aqueous suspensions. A specific state of the dispersion is observed at the
CSiO2 values corresponding to the bulk density of the initial silica powder.
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WHR-4GMS99Y4&_user=10&_coverDate=09%2F15%2F2005&_alid=1048560818&_rdoc=1&_fmt=high&_orig
=search&_cdi=6857&_sort=r&_docanchor=&view=c&_ct=4&_acct=C000050221&_version=1&
_urlVersion=0&_userid=10&md5=a2eaf0cc49659163bb35b0aa8a33b76c
10.
Dimensions Effects in Fumed Silica Nanoparticles by I.F. Myronyuk; V.I. Mandzyuk;
T.V. Gergel // PHYSICS AND CHEMISTRY OF SOLID STATE, v.6, #1, 2005, pp. 3438).
The investigation of fumed silica by means the infrared Fourier spectroscopy method allowed find
out that the length of siloxane bond increase in Si–O–Si chains with the decreasing of nanoparticles
average diameter, thus bonds feel the most lengthening in surface globule interlayer. The globule
“swelling” related to considerable Laplace pressure within small particles. There is the band in
SiO2 – spectra with the maximum absorption at 978-964 sm-1, which belong to dissymmetric atom
oscillations of siloxane bond of surface globule interlayer. The decreasing of concentration of
hydroxyl groups and absorbed water concentration in small particles reduction of concentration is
conditioned by reduction of number of surface silicon atoms in re-calculation per unit of area.
http://www.pu.if.ua/inst/phys_che/start/pcss/vol6/0601-03.pdf