Amphiphilic ODA/HY and ODA/ Hβ zeolites have been prepared via chemically coating octadecylamine (ODA) with alcohol as solvent. IR and titrimetric results indicate that ODA molecules are chemisorbed on the acidic sites in zeolite, showing the higher thermostability and alcohol-resistance. These amphiphilic zeolites contain both the hydrophobic and hydrophilic groups, orient at the liquid-liquid phase-boundary in both cyclohexane/water and water/carbon tetrachloride systems, and exhibit the potential to be used in the phase-boundary catalysis and adsorption. No by-products with strong acidity are formed in this approach, therefore, it can be used to prepare amphiphilic acidic zeolites with low Si/Al ratio. amphiphilic zeolite, octadecylamine, chemically coating, preparation, characterization For the catalytic reaction systems containing immiscible water and oil reactants, the conventional strategy is to add co-solvent to or vigorously stir the systems to drive the reactions [1] . However, these treatments make the workup procedure very tedious and may cause environment pollution. Recently, Nur et al. [2][3][4] have developed a new environmentally benign approach, called phase boundary catalysis (PBC), in order to replace conventional catalytic process. Due to their hydrophilic surface, synthesized zeolites exhibit poor catalytic performance in PBC process. The key factor to achieve high PBC activity is to prepare amphiphilic zeolite particles, which contain both hydrophilic and hydrophobic regions. In current literature, amphiphilic zeolite particles are usually prepared by aggregation of hydrophilic particles with a small amount of water followed by modifying their external surfaces with a hydrophobic alkylsilylation reagent, i.e. n-octadecyltrichlorosilane (OTS) [2][3][4] or trimethylchlorosilane (TMS) [5] . Because hydrochloric acid is formed as a by-product during the modification of these alkylsilylation reagents, the framework of zeolite with low Si/Al ratio, such as Y zeolite, would collapse under such a strong acidic condition. Therefore, it is necessary to develop some new approaches for the preparation of amphiphilic zeolites. In this paper, we attempt to prepare amphiphilic zeolite particles via the strong interaction between basic molecules and acidic sites on zeolite surfaces, using alkylamine as hydrophobic modifying reagent.
ExperimentalA certain amount of octadecylamine was dissolved into alcohol under magnetically stirring, and then HY (or Hβ) zeolite was added into this solution. After stirring overnight, the mixture was heated under magnetically stirring for vaporizing most of the solvent followed by drying at 373 K in an oven. X-ray diffraction (XRD) analysis was performed on a Rigaku D/max-rA diffractometer employing CuKα radiation. The X-ray tube was operated at 40 kV and 40 mA. Acidity of samples was measured by titration [6,7] . FT-IR spectra were recorded on a Bruker