CONICET | Buscador de Institutos y Recursos Humanos

The increasing resistances of bacteria against common synthetic antibiotics causes serious problems in medical treatment especially in open wounds, skin burns or surgery . In general a trend towards natural bactericidal drugs search is predominant in recent years. Anyway, these compounds are usually present in living species only at small concentrations. For their recovery, organic solvents are increasingly replaced by harmless methods like supercritical extraction. Supercritical carbon dioxide (CO2) is not only known as a possible solvent for valuable compounds but also for its high diffusion ability in organic matter. The latter property may be used for impregnating solid matrices with an adsorbate. During diffusion, CO2 carries dissolved substances into the matrix for being retained after pressure release. The mentioned properties of CO2 suggest to develop a combined process for extracting natural compounds with posterior application on a solid matrix. The envisaged compounds may either by absorbed within the solid or adsorbed on its surface as an adhering coating. In any case, kinetics and optimum processing conditions may differ between the extraction and the application step. In this work a process design comprising a closed solvent (supercritical CO2) cycle is presented which includes an extractor and an adsorber column that can be operated independently from each other. A view chamber allows for optical inline detection of precipitation and swelling effects.Optimum operating conditions regarding pressure, temperature and processing time (Preliminary parameters) are determined by optical and gravimetrical measurements under pressure as well as extraction kinetics of the natural compounds. As base biomaterials, organic-inorganic composites are used while a bactericidal compound are retrieved from patagonian living species.