Kirik, S. D.

Kozlova, S. A.

Zaitseva, Yu. N.

BSU Digital Library

 21 
Stability of sulphide-fucntionalized SBA-15 in aqueous medium  
S. A. Kozlova, Yu. N. Zaitseva, S. D. Kirik 
1Institute of Chemistry and Chemical Technology SB RAS, Krasnoyarsk, Russia, 
 e-mail: SAKozlova@gmail.com 
2Siberian Federal University, Krasnoyarsk, Russia 
  The stability of mesoporous mesostructured MCM-41 and SBA-15 materials has been previ-
ously investigated [1]. In [2] the sulfide-functionalized sorbents (Fig.) based on these materials 
have been obtained and their potential availability for selective sequestration of heavy and noble 
metals from aqueous solutions was proved. The questions arise: How stable these sorbents are? 
How long can they function as a sorbent in solutions processing. The preliminary results on sta-
bility  of  sulfide-functionalized  SBA-15  sorbents in aggressive media have been obtained. The 
R-S-R’ type materials have been treated with water, hydrochloric, nitric and sulfuric acids, am-
monia. The pickling has been carried out by processing the materials for one hour in 1 М acids 
and 0.1 М ammonia solutions. The solid / liquid ratio was equal to 1: 100. Similar experiments 
have been performed on silica gel to compare. 
 
 
 
Fig. The sulfide-functionalized SBA-15 sorbent [2]. 
 
 The control of pored silicate structure, organic part content and sorption ability has been real-
ized during the pickling process. For that process the mass loss of samples has been observed. 
The mass loss for the functionalized silica-gel samples was greater than that for functionalized 
SBA-15 samples, especially in case of acidic media. We also observed an increase in the specific 
surface areas and pore volume during the pickling process. However, the materials have a high 
degree of structural order before and after the pickling process that was confirmed by accurate 
X-ray diffraction. The silicate framework does not degrade according to IR-spectroscopy data as 
well.  We can observe three bands in the region 400-1200 cm-1 that respond to Si-O-Si vibrations 
in tetrahedron SiO4. These bands stay invariable after treatment in all aggressive media.  
 Nevertheless the part of organic component insignificantly decreases. This is due to the de-
composition process of the surface graft layer. The graft layer decomposition leads to decreasing 
sulfur content and as a consequence to decreasing the sorption ability of materials. However, in 
these experiments we have used a very harsh environments than it is needed for practical sorp-
tion processes. Thus, these materials can be employed in different technological solutions for a 
long time. 
 
Aknowledgement. This work was supported by RFBR (project №14-03-31630). 
 
References 
1.   S.A. Kozlova, S.D. Kirik. Microp. Mesop. Mater. (2010) 133: 124. 
2.   S.A. Kozlova, Yu.N. Zaitseva, S.D. Kirik. Glass Phys. Chem. (2014) 40: 60. 
 
OH + CH3      O
 O      CH3                                         OH
O      CH3
Si      (CH2)3      O       CH2       CH       CH2      S
 O      CH3                                         OH
O      CH3
Si      (CH2)3      O       CH2       CH       CH2      S
  SiO2
 C6H5CH3
CH3OH
  SiO2 O Si
O  + CH3      O
O      CH3              OH
O      CH3
Si      (CH2)3 O    CH2   CH    CH2      S
O      CH3              OH
O      CH3
Si      (CH2)3 O    CH2   CH    CH2      S
  SiO2
 C6H5CH3
CH3OH
  SiO2 O i


Stability of sulphide-fucntionalized SBA-15 in aqueous medium

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Stability of sulphide-fucntionalized SBA-15 in aqueous medium

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