Silica inorganic

Phenolic resin with an organic (nylon), inorganic (silica), or refractory (carbon) reinforcement Precharred epoxy impregnated with a noncharring resin... 

The type of membrane cleaning required depends on both the type and degree of fouling experienced, but typically it is either organic (bacterial slimes, natural organics, or process foulants and nutrients) or inorganic (silica, carbonate, sulfate, or phosphate deposits). 

Another advantage of using inorganic silica particles over polymer particles is that they don t shrink or swell when exposed to aqueous or nonaqueous environments. In the case of... 

Figure 3.8. An early example of a hybrid support applied in the rhodium catalysed hydroformylation operated in a continuous flow reactor. Polystyrene containing phosphite ligands were grafted on inorganic silica, such that the catalyst will behave as a homogeneous catalyst when using a compatible solvent...

In general, the solid surface in molecularly doped organic-inorganic silica gels participates actively in the reaction mechanism, by ... 

The hybrids generated by the sol-gel process combine the flexibility and mechanical strength of the organic constituent with the hardness, stiffness and transparency of the inorganic silica network. Hardness is often further conferred by the employment of other inorganic oxide particles (such as alumina or titania). This first started in the 1980s when... 

The second major wastewater discharge (about 1.2m /min or 318 gpm) is from the bottom of the scrubbers used after a dry dust collector cyclone to reduce the dust concentration in the effluent air stream from the phosphate dryer. The underflow of the scrubber contains a high concentration of dust and mud, laden with tiny phosphate organic and inorganic silica and clay particles, and is disposed of in a nearby stream. The main pollutant in the flow to the stream is P2O5 at a concentration of nearly 1200 mg/L and it remains mostly as suspended particles. 

Almost at the same time (1996), Tanaka and co-workers [33] and Fields [34] expanded the research field of continuous polymer support by the introduction of (derivatized) inorganic silica rods, which were prepared by sol-gel process of silane precursors [tetramethoxysilane (TMOS) or dimethyloctadecylchlorosilane (ODS)] in the presence of poly(ethylene oxide) (PEO) as porogen. 

The preferentially employed approach for the fabrication of inorganic (silica) monolithic materials is acid-catalyzed sol-gel process, which comprises hydrolysis of alkoxysilanes as well as silanol condensation under release of alcohol or water [84-86], whereas the most commonly used alkoxy-silane precursors are TMOS and tetraethoxysilane (TEOS). Beside these classical silanes, mixtures of polyethoxysiloxane, methyltriethoxysilane, aminopropyltriehtoxysilane, A-octyltriethoxysilane with TMOS and TEOS have been employed for monolith fabrication in various ratios [87]. Comparable to free radical polymerization of vinyl compounds (see Section 1.2.1.5), polycondensation reactions of silanes are exothermic, and the growing polymer species becomes insoluble and precipitates... 

Schlautman, M. A., and J. J. Morgan, Sorption of perylene on a nonporous inorganic silica surface - Effects of aqueous chemistry on sorption rates , Environ. Sci. Technol., 28, 2184-2190 (1994). 

The most intriguing synthetic approach is the conversion of inorganic silica to spirosilicate by the reaction with a 1,2-diol and alkali hydroxide (equation 13)36. 

A bridged bis-spirosilicate with an ethylenedioxy bridge (85) (i.e. based on the SiOs ligand framework) was prepared directly from inorganic silica and ethylene glycol in the presence of potassium hydroxide (equation 13)36. 

Inorganic Silica gels 1-30 Volasphere, Florisil Solvent PCBs, pesticides High -400°C High... 

We found that inorganic helical structures such as helical silica serve as chiral triggers for asymmetric autocatalysis (Scheme 23). In the presence of helical silica, the enantioselective addition of z-P Zn to 2-alkynylpyrimidine-5-carbaldehyde 11 was examined. In the presence of right-handed helical silica, (S)-5-pyrimidyl alkanol 12 was formed [123]. In contrast, in the presence of left-handed helical silica, (S)-5-pyrimidyl alkanol 12 with high ee was obtained. These results clearly show that asymmetric auto catalysis can discriminate the helical structure in artificially tuned inorganic silica. 

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