Post-treatments hydrolysis

AOS and MES are also produced using sulfonation methodologies similar to that for LAS (falling film sulfonation) although they require some additional post-treatment steps. When sulfonating a-olefins to produce AOS, a final hydrolysis step is required in order to eliminate sulfone by-products formed during the sulfonation. 

Enhanced Enzymatic Hydrolysis of Steam-Exploded Douglas Fir Wood by Alkali-Oxygen Post-treatment... 

Compound 13b was synthesized in four steps via key intermediate 52, in which the configuration of the hydroxyl group at the C-3 position of 50 was inverted. Compound 50 was reacted with trifluoromethanesulfonyl anhydride and pyridine to give triflate 51 (96% yield), which was then reacted with KN02 in the presence of 18-Crown-6, followed by post-treatment of the resulting nitrous ester with water to afford key intermediate 52 (80% yield) [55, 56]. Reduction of the azide moiety of 52 by trimethylphosphine or hydrogenation on Pd on carbon, followed by hydrolysis of the ester moieties gave 13b (48% yield). 

N-doped Ti02 nanomaterials have also been synthesized by hydrolysis of TTIP (Ti(OCH(CH3)2)4) in a water/amine mixture and the post-treatment of the Ti02 sol with amines [408 12] or directly from a Ti-bipyridine complex [400]. 

An alternative post-treatment modification method involves treatment of the zeohte with a sodium hydroxide (alkaline) solution (16-23). Treatment of ZSM-5 with a sodium hydroxide solution extracts sihca from the framework via hydrolysis, with minimal alumina extraction (16-23). Groen et al. (12) have previously reported mesopore development in the 2-50 nm range using this method. The development of mesopores, which is due to the enlargement of micropores (24), leads to significant increases surface area and pore volume. Several studies have shown that an alkaline post-treatment of ZSM-5 results in enhanced intrazeolitic mass transfer rates of adsorbates (21-23,25). 

Since in multilayer interference systems, denser layers can be deposited, improved abrasion resistance is expected compared to porous coatings. Multilayer AR films can readily be deposited from traditional polymeric sols, and low temperature post-treatments allow processing such films on polymer substrates. For instance, multicomponent AR coatings have been applied on PC and acrylate substrates by hydrolysis and condensation of silanes and various metal alkoxides (Ashley, 1986). However, it seems that low temperature... 

Hydrolysis and Polycondensation. As shown in Figure 1, at gel time (step C), events related to the growth of polymeric chains and interaction between coUoids slow down considerably and the stmcture of the material is frozen. Post-gelation treatments, ie, steps D—G (aging, drying, stabilization, and densification), alter the stmcture of the original gel but the resultant stmctures aU depend on the initial stmcture. Relative rates, of hydrolysis, (eq. 2), and condensation, (eq. 3), determine the stmcture of the gel. Many factors influence the kinetics of hydrolysis and... 

As a totally different post-synthesis method that is firmly based on the structural charaderistics of MWW, reversible strudural conversion between 3D MWW silicate and its corresponding 2D lamellar precursor MWW (P) has been developed to construd more active Ti species within the framework [24, 70], Figure 4.7 illustrates the strategy of this post-synthesis method of reversible strudural conversion. First, highly siliceous MWW is prepared from hydrothermally synthesized MWW boro-silicate by the combination of caldnation and acid treatment. Second, the MWW silicalite is treated with an aqueous solution of HM or PI and a Ti source. A reversible structure conversion from MWW into the corresponding lamellar precursor occurs as a result of Si-O-Si bond hydrolysis catalyzed by OH, which is supplied by basic amine molecules. This is accompanied by the intercalation of the amine molecules. 

Introduction of RLi-unreactive silicon substituents has advantages in protection of Ar-C-H and Ar-CH3 sites. Thus taking advantage of the cooperativity of amide and methoxy DMG, metalation-silylation followed by metalation-E+ quench affords, after fluoride-mediated desilylation and amide hydrolysis, a route 1,2,5-substituted benzoic acids, 18 —> 19 (Scheme 5). Lateral metalation, of considerable utility in post-DoM chain extension [19], followed by double silyla-tion and further DoM-E+ quench and the same fluoride and acid treatment steps, furnishes 1,2,3,4-tetrasubstituted aromatic compounds, 20 —> 21 [10, 20],... 

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