Thermal analysis was emplyed to investigate the interaction between the framework of siliceous FER type zeolite sample and the adsorbed organic compounds with various functional groups, such as alkyl - amines, alkyl - alcoholes, n - alkanes. The zeolite sample is in a form of single crystals and possesses perfect framework without Si (1Al) and Si－OH defect confirmed with XRD, FT-IR and ^29 Si MAS NMR. The affinity index (AT value) was determined and used to compare the interaction between the adsorbed organic compounds and the framework. The organic molecules containing framework - philic functional group such as amino - group and n - alkanes show very high AT values. The organics containing framework - phobic functional groups such as hydroxyl group show lower AT values. On the other had the chain length of alkyl group also affects on the values of AT as well.

Key words: ZEOLITE, THERMAL ANALYSIS, THERMOGRAVIMETRY, ORGANIC COMPOUNDS, ADSORPTION, HOST, INTERACTIONS