Crystallization of silicalite-1 from clear synthesis solutions: Effect of template concentration on crystallization rate and crystal size

Synthesis of silicalite-1 powders and membranes from initially clear solutions with different tetrapropylammonium hydroxide or bromide concentrations was studied. While tetrapropylammonium bromide acts only as template, tetrapropylammonium hydroxide provides both the template and hydroxyl ions to the synthesis medium. The effects of template and hydroxyl ion concentration on the product yield, crystallization rate and crystal size were investigated. Pure and highly crystalline silicalite-1 was obtained with all compositions. The nucleation time decreases from 100 h to 20 h and the crystal size decreases from 3.5 mu m to 0.35 mu m as the template amount x is increased from 5 to 30 moles at a batch composition of 80SiO(2 center dot)xTPAOH center dot 1500H(2)O at 95 degrees C. Yield of silicalite-1 passes through a maximum at intermediate TPA concentration. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim


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A dipyrrolyl monomer was synthesized via the reaction between 4-pyrrol-1-yl phenol and decanedioyl dichloride. The electrochemical behavior of this monomer was studied. Polymerization of decanedioic acid bis-(4-pyrrol-1-yi-phenyl) ester (DAPE) was achieved by chemical and constant current electrolyses methods. Copolymerization of DAPE with thiophene was performed by constant potential electrolysis in acetonitrile-tetrabutylammonium tetrafluoroborate (TBAFB), dichloromethane-TBAFB, solvent-electrolyte couple...
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CAMURLU, P; Çırpan, Ali; Toppare, Levent Kamil (Elsevier BV, 2005-08-15)
Octanoic acid 2-thiophen-3-yl-ethyl ester was synthesized via the reaction of 3-thiophene ethanol with octanoyl chloride. The resulting monomer was electrochemically homopolymerized in the presence of tetrabutylammonium tetrafluoroborate as the supporting electrolyte, in the acetonitrile/borontrifluoride ethyl ether solvent system. The resulting polymer was characterized using various experimental techniques. Spectroelectrochemistry analysis of the homopolymer reflects electronic transitions at 434, approxi...
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Citation Formats
B. Soydas, P. Z. Çulfaz Emecen, H. Kalıpçılar, and A. Culfaz, “Crystallization of silicalite-1 from clear synthesis solutions: Effect of template concentration on crystallization rate and crystal size,” CRYSTAL RESEARCH AND TECHNOLOGY, pp. 800–806, 2009, Accessed: 00, 2020. [Online]. Available: