The structural and sorption characteristics of a composite material consisting of a silica aerogel loaded with flufenamic acid were investigated using a variety of nuclear magnetic resonance techniques. The composite structure was analyzed using magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy, which revealed significant interactions between the aerogel matrix and the FFA molecules. Solid-state 29Si NMR provided insights into the aerogel's stability, while 1H and 13C NMR confirmed the presence of FFA in the matrix, with signals from FFA molecules observed alongside tetraethoxysilane (TEOS) groups. Ethanol-induced desorption of FFA led to narrowed spectral lines, suggesting the breaking of intermolecular hydrogen bonds. 19F MAS NMR spectra indicated changes in FFA local environments upon loading into AG pores. Evaluation of CO2 sorption characteristics using 13C NMR demonstrated a slower sorption rate for AG + FFA than that for pure AG, attributed to decreased pore volume. Furthermore, nuclear Overhauser effect spectroscopy (NOESY) was employed to explore the conformational behavior of FFA within the aerogel matrix. The results indicated a shift in conformer populations, particularly those related to the rotation of one cyclic fragment relative to the other. These findings provide insights into the structural and sorption characteristics of the AG + FFA composite, which are valuable for developing novel drug solid forms. © 2024 The Royal Society of Chemistry.
Original languageEnglish
Pages (from-to)27301-27313
JournalPhysical Chemistry Chemical Physics
Volume26
Early online date17 Oct 2024
DOIs
StatePublished - 2024

    Research areas

  • Atomic emission spectroscopy, Fourier transform infrared spectroscopy, Hydrogen bonds, Nuclear magnetic resonance spectroscopy, Silicones, Composites material, Flufenamic acid, High pressure, Magic angle spinning nuclear magnetic resonance, Material loaded, matrix, Nuclear overhauser effect spectroscopy, Silica aerogels, Sorption characteristics, Structural characteristics, Magic angle spinning

ID: 126740126