Structure-Direction by Flexible, Hydrophilic OSDAs

A piece of experimental evidence to support the above idea can be drawn from zeolite syntheses in the presence of N,N,N,N, N, N -hexam-ethylpentanediammonium (Me -diquat-d) ion, a slightly shorter OSD A than Et6-diquat-5, the only known OSD A leading to the crystallisation of ZSM-57. This flexible diquaternary cation was reported to give at least four different zeolites i.e. EU-1 (EUO), ZSM-48 ( MRE), ZSM-12 (MTW), MCM-22(P)] depending on the A1 content and type and concentration of alkali cations in the synthesis mixtures. Since neither of 

Studied and industrially important zeolites,together with excellent hydro-thermal stability, we look forward to new chemical technologies based on their own shape selectivity effects. 

The synthesis of TNU-9 in the presence of 1,4-MPB was found to be possible only from synthesis mixtures with a very narrow range of Si02/ AI2O3 and Na0H/Si02 ratios, which is also the case of the 1,5-MPP-mediated synthesis of mainly due to the flexible nature of the 

Run no. Gel composition SiOi/AlzOj NaOH/SiOz Time (days) Product  

The product appearing first is the major phase, and the product obtained in a trace amount is given in parentheses. 

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