Liquid crystals high-pressure autoclave

Zeolite syntheses start from alkaline aqueous mixtures of aluminum and silicon compounds. The reactions are sometimes carried out at atmospheric pressure but more often in a high-pressure autoclave. The controlled crystallization of a particular zeolite requires careful control of the concentration and stoichiometry of the reaction partners, the temperature, and the shearing energy of the stirrer. After mixing of the liquid phase and formation of a gel, a transition of the gel phase in to the liquid aqueous phase occurs, whereby crystalline zeolites are formed from the amorphous particles. 

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