Periodic mesoporous organosilicas (PMOs) with unusually large pores and high BET surface areas have been synthesized using triblock PEO-PPO-PEO copolymer P123 as the structure-directing agent and 1,2-bis(trimethoxysilyl)ethane (BTME) as the organically bridged silica source.

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from the present FAU-on-EMT overgrowth material by selectively dissolving the siliceous EMT core, which occurs when the crystallization time is prolonged.Experimental EMT (SiO 2 ) crystals (obtained from Ludox HS-40 (Du Pont)), Gibbsite (Al 2 O 3 , Fluka), NaOH pellets (Merck), 1,4,7,10,13, Acros), and distilled water were mixed according to the following molar ratios [18]: 10 : 1 : 4.8 : 0.97 : 135 respectively. The resulting gel was aged for 3 days at room temperature before crystallization was conducted in a PTFE-lined stainless steel autoclave. After 11 days at 373 K, a wet cake of EMT crystals was recovered by vacuum filtration. 6.0 g of this cake was mixed with 29.1 g of a second gel, prepared in the same way but with a molar NaOH proportion of 7.5. The sample in Figure 3, however, was obtained by adding 13.3 g of the wet EMT cake to 22.4 g of the gel. Crystallization was performed at 373 K without aging. After 3 days, the solid product was recovered by vacuum filtration, washed with deionized water, dried at 333 K, and finally calcined at 823 K in a muffle furnace. The remaining part of the EMT cake was washed with deionized water until the pH of the water was below 10, and then dried at 333 K. Calcination was done in a muffle furnace at 823 K for 20 h.XRD patterns were collected on an automated Siemens D-5000matic diffractometer using Cu Ka radiation. The XRD profiles were recorded in the range of 2y values between 4 and 55 with steps of 0.02 and counting times of 1.2 s. SEM pictures were taken on a Jeol superprobe 733 and on a Philips XL30 FEG apparatus. A gold film was sputtered onto the samples supported on alumina disks prior to observation.HREM investigations were carried out with a 200 kV Philips CM200 Ultra Twin apparatus with a point-to-point resolution of 0.19 nm. The zeolite powder was deposited onto a holey carbon film; the zeolite crystals remained stable under the electron beam irradiation for at least several minutes. By choosing intermediate magnifications, the beam damage could also be minimized.Nitrogen adsorption isotherms at 77 K were recorded using an Omnisorp-100 analyzer from Coulter, operating in the continuous flow mode. Calcined samples were outgassed at 673 K under high vacuum (10 ±6 kPa) for at least 12 h. Micropore volumes were derived from the adsorption isotherm using the t-plot method of Lippens and de Boer. [19] 29 Si MASNMR measurements were performed on a Bruker 400 MSL spectrometer with a magnetic field of 9.4 T. The experiments were run at 79.5 MHz, with a pulse length of 4 ms, a pulse interval of 5 s, a spinning rate of 4 kHz, for 11 000 scans.The use of self-assembled molecular arrays of surfactant molecules as supramolecular templates allows the generation of nanostructured materials. These compounds, exemplified by the Mobil Corporations M41S silica-based phases, [1] tend to show periodicity on the 2±10 nm scale. The formation of this kind of material represents an important step in the quest to control structural order on length scales between atomic and macrosc...

We present results on new periodic mesoporous organosilicas synthesized with 1,4-bis(triethoxysilyl)benzene (BTEB), 1,2-bis(trimethoxysilyl)ethane (BTME) and bis[3-(trimethoxysilyl)propyl]amine (BTMPA). The materials show high inner surfaces up to 830 m2/g and pore diameters in the range of 2.7 to 3.7 nm depending on the structure directing agent used. In case of BTEB as precursor and triblock copolymer Pluronic P123 as structure directing agent exceptional thick pore walls were obtained (7.2 nm). Characterization was carried out by P-XRD, nitrogen physisorption analysis, thermoanalytical methods and IR spectroscopy.

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