Study On The Porous Nano-Materials Of Al-and Ti-Pillared Montmorillonites

The pillared montmorillonites could be used as catalysis of molecular sieve and environmental materials for their good properties such as large surface area, adjustable pore structure, strong acid activation and so on. Recently, the pillared montmorillonites were prepared based on Al-pillared montmorillonites (Al-PLMs). Therefore it was important to study it's preparation and the factors deeply. By means of A1C13 hydrolyzing in NaOH solution, the author prepared Al-PLMs which were characterized by XRD, XRF, FT-IR, SEM etc. Some factors in the experiments were studied in detail. The result showed that the concentration of A1C13, NaOH, Al-pillaring solution didn't affect the basal spacing and thermal stability of Al-PLMs greatly. The high OH/Al ratio and large amounts of Al-pillaring solution favored the basal spacing and thermal stability of Al-PLMs. The surface area would declined if OH/Al ratio was too high or the amounts of Al-pillaring solution was too much. The aging of Al-pillaring solution at higher temperature improved the basal spacing and thermal stability, surface area and pore volumes of Al-PLMs. However the properties of Al-PLMs were independent of the adding order between the montmorillonite solution and the Al-pillaring solution. With washing times increasing the crystallization of Al-PLMs got well.Based on the above experiments, the author studied the mixed metallic pillared and modified montmorillonites. The experimental result indicated that the microporous structure of Fe-Al-PLMs was affected by the changing of interlayer Fe-Al polymer with different Fe/Al ratio. But the presence of Al iron was helpful to incorporate Fe iron into interlayer of montmorillonites.. Introducing Zr helped Al-PLMs getting better larger spacing, thermal stability, surface area and pore volumes. It's successful to apply Zr-Al-PLMs to treat wastewater containing Cr(VI) iron. The experiment of modifying Al-PLMs by PVA showed that the order of adding starting materials (Al-pillaring solution, PVA, montmorillonite solution) was related to the property of Al-PLMs. The PVA as precursor was beneficial for Al to go into interlayer of the clay and to form larger basal spacing porous clay. The surface area and pore volumes of Al-PLMs increased mainly because of increasing the external surface area and mesoporous volumes after acid-activating. This conclusion confirmed that the microporous structure of pillaring clay depends upon the interlayer pillar.For comparison and further research of porous materials, the author prepared Ti-PLMs and mixed(Ti) metallic-PLMs in the way former and using TiCl4 C2H5OH and glycerol as the raw materials. The basal spacing of the product was 19.78A with sharp d00, peak. Its surface area was 189mVg and pore volume was 0.162cm3/g. All these results showed that this preparing method is better than that of TiCl4 hydrolyzing in HC1. Zr-Al-PLMs had more micropore than Ti-PLMs.