Silicas, mesoporous

Figure 1). Finally, high ordered pure silica mesoporous material, containing lipase enzyme by entrapping procedure, has been obtained by sol-gel method (XRD results not showed).

Polyoxyethylene alkyl ether and in particular decaoxyethylene oleyl ether CigHj5 (CH2CH20)io can be used as templating agent for silica mesoporous materials formation. The synthesis can be performed under both acidic or basic conditions with tetramethoxysilane (TMOS) as silica source while no mesoporous compound was obtained with sodium silicate. 

Change of reorientational-vibrational relaxation upon capillary condensation in silica mesopores... 

Silica (mesoporous) impregnated with copper(ll) Laboratory solutions Ambient 5-6 As(V)... 

It is a mass transfer between a mobile, solid, or liquid phase, and the adsorption bed packed in a reactor. To carry out adsorption, a reactor, where a dynamic adsorption process will occur, is packed with an adsorbent [2], The adsorbents normally used for these applications are active carbons, zeolites and related materials, silica, mesoporous molecular sieves, alumina, titanium dioxide, magnesium oxide, clays, and pillared clays. 

The obtained experimental results indicate that the hydrogen uptake at 77 K and 0.1 MPa in the silica mesoporous molecular sieve, MCM-41, is very low [147], Nevertheless, MMS have been used as templates for the creation of ordered porous carbon with tailored pore sizes, which can be applied in hydrogen storage [158],... 

Adsorbed horseradish peroxidase (HRP) on silica mesoporous materials The immobilized HRP on FSM-16 and MCM-41 with pore diameter of 50 A showed the highest enzymatic activity in toluene and thermostability in aqueous solution at a temperature of 70°C [4]... 

Fig. 6 Schematic representation of the synthetic route to obtain constitutional silica mesoporous membranes is (a) filled with mesostructured silica-CTAB, (b) then calcinated, (c) reacted with hydrophobic ODS and finally filled with the hydrophobic carriers. Generation of directional ion-conduction pathways which can be morphologically tuned by alkali salts templating within dynamic hybrid materials by the hydrophobic confinement of ureido-macrocyclic receptors within silica mesopores [130]...

According to the data from calorimetric investigations of the adsorption of ammonia, unlike silica gel, the pure-silica mesoporous sieve MCM-41 possesses specific although weak acidity. The introduction of titanium or zirconium, and parhcularly aluminum, ions into the structure of this sieve substantially increases the acid strength of the sorbent [120, 121]. 

Those results indicate two st lges of zeolite crystallization in silica pellets formation of small zeolite ZSM-5 crystals (0.025 pm) in the silica mesopores and large zeolite crystals (1-4 pm) in the silica macropores and on the outer surface of silica pellets followed by faster crystallization in the interior of the carriers pellets. At this second stage the mesopores and small zeolite crystals inside them do not grow but the pellets structure fails forming large slabs of amorphous silica with incapsulated zeolite crystals not accessible for adsorption and catalysis. 

Other Metal-substituted Silica Mesoporous Materials... 

K. Miyasaka, L. Han, S.N. Che, and O. Terasaki, A Lesson from the Unusual Morphology of Silica Mesoporous Crystals Growth and Close Packing of Spherical Micelles with Multiple Twinning. Angew. Chem. Int. Ed., 2006, 45, 6516-6519. 

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