Opinion:  Sometimes called the thermodynamic effect, long tails (chains) with active ligands/points on the ends will form cycles/loops rather than linear chains.  I have encountered this before when trying to craft polymers.  Design the monomer to discourage/prevent bending.

thank you sir, I will consider your opinion. However, long chain surfactants are able to form ordered mesoporous materials which are amorphous/polycrystalline. However no crystallinity is observed. But,i should agree with you since designing the polymer with organo silane attached to active head will succeed in forming hierarchical zeolites.

Spontaneous mesostructuration is easily destroyed when slightly unsuitable conditions are used, such as inadequate concentration or too high temperature in the autoclave. You might try higher concentrations of ammoniums as well as milder temperatures. Also too long reaction times may be in favour of more stable phases, i.e. of less porous ones. Time therefore should be another parameter to look at. Good luck.

Alain

Thank you sir, high ammonium concentrations (multiquaternary ammonium ions) will accomplish the task. Its established and extensive research is going on these hierarchical zeolites. but to meet industrial demands, ain't sure these structures meet the challenges since this synthesis end up in to 2D hexagonal porous materials which have diffusion limits and also less orderedness. I want to induce true mesoporosity/ hierarchy (eg: Silicogermanate ITQ-43)  by using SDAs (zeolite templating) instead of supramolecular templating.

Thank you Karl G. Strohmaier, J Cejka, Avelino Corma, and Stacey Zones

Solvation of SDA plays an important role in crystallization of zeolite.

Hydrophobicity increases as the size of the SDA(long alkyl chains) increases, which limits its solubility in aqueous medium and thus unable to form solvated cations. For a successful crystalline framework, the interaction of solvated cations and condensing silicate species in solution has a profound effect.

and also as the above professors suggested C/N+ ratio in organic moieties also plays a vital role in the formation of SDA hydration sphere. Hence, by using long chain SDAs, i am increasing the hydrophobic nature of my SDA which restricted its solubility and hence no nucleation of crystal, whereas in multiquaternary SDAs has low C/N+ ratio were able to overcome this limitation. Hence solubility of SDA is one of the factor.