PROPRIETATILE A DOI ZEOLITI NATURALI MODIFICATI CU ULEI ESENTIAL DE OREGANO/THE PROPERTIES OF TWO NATURAL ZEOLITES MODIFIED WITH OREGANO ESSENTIAL OIL

• Published in: Revista Romana de Materiale Vol. 43; no. 1; p. 48
• Main Authors: Kaya, Durmus Alpaslan, Vuluga, Zina, Nicolae, Cristian Andi, Radovici, Constantin, Albua, Madalina Georgiana
• Format: Journal Article
• Language: English
• Published: Bucharest Foundation for Materials Science and Engineering - "Serban Solacolu" 01.01.2013
• Subjects: Food; Medical research; Minerals; Morphology; Oils & fats; Pharmaceuticals; Physical properties; Studies; Zeolites
• ISSN: 1583-3186; 2457-502X

The aim of this study was to prepare zeolites modified with oregano essential oil and to establish their morphological and thermal properties as well as the release ability of essential oil from zeolites. The chemical composition of oregano oil was determined by GS-MS. The crystalline structure and chemical composition of two natural zeolites were performed by X-ray diffraction (XRD) and X-ray fluorescence (EDXRF). Both natural zeolites presented similar structure with clinoptilolite type. The thermal characteristics of oregano oil, zeolites and their combination were carried out by thermogravimetric analyses (TGA). The oregano oil was loaded in zeolite in order to improve its stability. It gradually evaporated so that the percentage of oil removed after 2h from zeolites was two times lower than itself evaporation. This property allows to the natural combination between zeolite and essential oil to be used as basic material in medical, pharmaceutical, cosmetic and food industry. In the range of the used temperature (20°C÷800°C), the zeolite samples exhibit four endothermic effects (Table 2). The first step of decomposition is in the temperature range of 20°C÷100°C and represents the loss of water from the surface of zeolite. The decomposition took place with maximum speed at 37°C for Z-1 and at 47°C for Z-2. The other steps of decomposition, from 100°C to 800°C represent the desorption of water from the clinoptilolite component of the sample. Gregory et al. [27] proved that there are three types of water associated with clinoptilolite: "external" water, "loosely bound zeolite" water, and "tightly bound zeolite" water. Corresponding to Breger et al. and Alietti et al. [28-30], the middle portion of TGA curve, between 50°C÷200°C represents desorption of "loosely bound zeolite" water and the high temperature portion, from 200°C÷700°C, represents the loss of "tightly bound zeolite" water.