The behavior of desorption of organic adsorbate with different functional group, such as straight-chain alkane, straight-chain alkyl amine, straight-chain alkyl alcohols, on the channel of siliceous FER, MFI, FAU with perfect framework, were invested by thermal analytical method. The loading of adsorbate and affinity index, A_T values, were also calculated. The effects of different channel size on affinity index were measured. The results that can be obtained from the research included that the A_T values decrease with the decrease of the channel size of zeolites when the adsorbates have strong affinity with the Si-O framework structure of zeolites. On the other hand, the values of A_T will increase with the decrease of the channel size of zeolites when the adsorbates have strong 'phobic' with the Si-O framework of zeolites.

Key words: SILICON, ZEOLITE, INTERACTIONS, THERMAL ANALYSIS, ALKANE, TPD