Evaluation of the Stability of Biocidal Molecules Adsorbed on Mesoporous MCM-41 for Use in Air Purification Systems

This study focuses on the characterization of a potential passive air purification system based on the controlled release of natural biocides - specifically essential oils - adsorbed onto MCM-41 mesoporous silica particles. Iso-eugenol, linalool, and 4-terpineol were used as representative active compounds due to their bioactivity and favorable physicochemical properties. These compounds, derived from essential oils such as clove, cinnamon, lavender, and tea tree, were incorporated into MCM-41 using physisorption process. To evaluate the loading efficiency and release behavior of the active compounds, a combined analytical approach using Near-Infrared (NIR) spectroscopy and Headspace Gas Chromatography with Flame Ionization Detection (HS-GC-FID) was adopted. NIR spectroscopy, as a rapid and non-destructive technique, was used to estimate the amount of essential oil physically adsorbed onto the silica matrix. Chemometric techniques, including multivariate calibration and principal component analysis, were applied to interpret the complex NIR spectra and enhance quantification accuracy. Meanwhile, HS-GC-FID allowed precise monitoring of compound desorption under various temperature and humidity conditions. This integrated strategy offers a reliable and efficient method for developing eco-friendly air purification systems based on natural bioactive compounds.