Physicochemical Characterization and Drug Release Properties of Methyl-Substituted Silica Xerogels Made Using Sol–Gel Process

Adél Len, Giuseppe Paladini, Loránd Románszki, Ana Maria Putz, László Almásy, Krisztina László, Szabolcs Bálint, Andraž Krajnc, Manfred Kriechbaum, Andrei Kuncser, József Kalmár, Zoltán Dudás*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


In this work, a multi-analytical approach involving nitrogen porosimetry, small angle neutron and X-ray scattering, Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopies, X-ray diffraction, thermal analysis and electron microscopy was applied to organically modified silica-based xerogels obtained through the sol–gel process. Starting from a tetraethoxysilane (TEOS) precursor, methyltriethoxysilane (MTES) was added to the reaction mix-ture at two different pH values (2.0 and 4.5) producing hybrid xerogels with different TEOS/MTES molar ratios. Significant differences in the structure were revealed in terms of the chemical composition of the silica network, hydrophilic/hydrophobic profile, particle dimension, pore shape/size and surface characteristics. The combined use of structural characterization methods allowed us to reveal a relation between the cavity dimensions, the synthesis pH value and the grade of methyl substitution. The effect of the structural properties on the controlled Captopril release efficiency has also been tested. This knowledge facilitates tailoring the pore network for specific usage in biologi-cal/medical applications. Knowledge on structural aspects, as reported in this work, represents a key starting point for the production of high-performance silica-based hybrid materials showing enhanced efficacy compared to bare silica prepared using only TEOS.

Original languageEnglish
Article number9197
JournalInternational Journal of Molecular Sciences
Issue number17
Publication statusPublished - 1 Sept 2021


  • Captopril
  • Controlled release
  • Hybrid silica materials
  • Nanostructure
  • Sol–gel technique
  • Structural characterization

ASJC Scopus subject areas

  • Catalysis
  • Spectroscopy
  • Computer Science Applications
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry

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