Dry gel method

Supported zeolite membranes have been prepared using numerous procedures [4] such as alignment of crystals in electrical fields, electroplating, self-assembly, growth on organic molecular layers, covalent linkages, hydrothermal synthesis (in situ and ex situ), hydrothermal method microwave heating assisted, dry gel method (vapor-phase transport method and steam-assisted crystallization), synthesis at the interface between two fluid phases, etc. 

The so-called dry gel method [20-22] is another alternative for membrane synthesis where vapors containing templates (i.e., amines) and water are employed to crystallize silica or silica-alumina layers previously deposited onto the support (vapor-phase transport method) or where steam is used to crystallize silica and template or sUica-alumina and template dry layers previously deposited onto the support (steam-assisted crystallization). Using this approach, the reactant consumption is clearly diminished, an important issue for scale-up purposes on the other hand, synthesis time is delayed due to transport-controlled phenomena. 

The so-called dry gel method [36-38] is another alternative for membrane synthesis where vapors containing templates (i.e., amines) and water are employed to crystallize... 

Similar to the upgrading of pyrolysis vapors, the effect of metal incorporation was extensively studied. Hicks et al. tested ZSM-5, hierarchical ZSM-5 (meso-ZSM-5, synthesized using a dry-gel method followed by steam-assisted crystallization), and their Ce-incorporated analogues in the catalytic pyrolysis of glucose at 600°C [291]. ZSM-5 and Ce/ZSM-5 yielded mainly aromatics, while meso-ZSM-5 and especially Ce/meso-ZSM-5 exhibited product distributions greatly shifted from aromatics to oxygenated chemicals like aldehydes, furans. 

TS-l/MCM-41 catalysts synttiesized by the dry gel conversion method are shown to have hexagonal mesopores. The catalytic activity of synthesized TS-l/MCM-41 catalysts was tested with qroxidation reaction of olefins to reved that both the conversion of olefins and selectivity to epoxide are higher than those of H-MCM-41,... 

In this work, highly active epoxidation catalysts, which have hydrophobic surface of TS-1, were synthesized by the dry gel conversion (DGC) method. Ti-MCM-41 was synthesized first by a modifed method and the TS-l/MCM-41 catalysts were subsequently synthesized by the DGC method. The catalysts were characterized by the XRD, BET, FT-IR, and UV-VIS spectroscopy. TS-l/MCM-41 catalysts were applied to the epoxidation of 1-hexene and cyclohexene with aqueous H202to evaluate their activities for the epoxidation reaction. ... 

Titanium containing hexagonal mesoporous materials were synthesized by the modified hydrothermal synthesis method. The synthesized Ti-MCM-41 has hi y ordered hexa rud structure. Ti-MCM-41 was transformed into TS-l/MCM-41 by using the dry gel conversion process. For the synthesis of Ti-MCM-41 with TS-1(TS-1/MCM-41) structure TPAOH was used as the template. The synthesized TS-l/MCM-41 has hexagonal mesopores when the DGC process was carried out for less than 3 6 h. The catalytic activity of synthesized TS-l/MCM-41 catalysts was measured by the epoxidation of 1-hexene and cyclohexene. For the comparison of the catalytic activity, TS-1 and Ti-MCM-41 samples were also applied to the epoxidation reaction under the same reaction conditions. Both the conversion of olefins and selectivity to epoxide over TS-l/MCM-41 are found hi er flian those of other catalysts. 

Assays. Protein concentrations were measured by the method of Bradford (18) and the various contractile protein ATPase activities by tRe method of Martin and Doty (19). Gel electrophoresis was carried out by the method of Ames (20) on 1.5 ran polyacrylamide slabs using the discontinuous SDS buffer system of Laemnli (21). Dried gels were scanned at 550 nm for densiometry measurements. 

Alkaline earth oxides (AEO = MgO, CaO, and SrO) doped with 5 mol% Nd203 were synthesised by both evaporation and sol-gel methods. According to the first method, water solution of nitrates was evaporated under continuous stirring, dried, and nitrate mixture was decomposed at corresponding temperatures (Table 1) for one hour (samples designated Ev). All samples were calcined at 650°C for 3h after the decomposition. In the sol-gel method the samples (designated SG) were obtained... 

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