Crystallization and crystal morphology of silicalite-1 prepared from silica gel using different amines as a base

Ban, Takayuki; Mitaku, Hideki; Suzuki, Chiharu; Matsuba, Jun; Ohya, Yutaka; Takahashi, Yasutaka

doi:10.1016/j.jcrysgro.2004.10.010

Cited by 30 publications

(14 citation statements)

References 28 publications

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“…Small spherical particles, some of which resemble lathshaped ZSM-5 crystals were observed to form on the twinned crystals (disc intergrowths). It is well-known that MFI-type zeolite crystals may have different forms, such as spheres, rods, hexagonal disks, etc., depending on the synthesis conditions [18]. The small particles may indicate the formation of new nuclei.…”

Section: Resultsmentioning

confidence: 99%

“…Synthesis experiments were carried out in a clear solution with the composition of 250TPAOH: 400Na 2 O:Al 2 O 3 :1200SiO 2 :114200H 2 O, which was quite similar to some compositions reported in the literature [18]. Fumed silica (Aerosil, Degussa), granular sodium aluminate (Riedel-de Haen), anhydrous NaOH pellets (Carlo Erba), TPAOH solution (Fluka, 20%) and deionized water were used.…”

Section: Methodsmentioning

confidence: 99%

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Substrate heating method for coating metal surfaces with high-silica zeolites: ZSM-5 coatings on stainless steel plates

Tatlıer¹,

Demir²,

Tokay³

et al. 2007

Microporous and Mesoporous Materials

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Syntheses of ZSM-5 coatings on stainless steel plates were carried out via the substrate heating method. The reaction mixture was kept at temperatures below 100°C, while the metal plates were heated to temperatures above 100°C. It was demonstrated that continuous ZSM-5 coatings of different textures with different crystal morphologies and void fractions could be formed. ZSM-5 coatings were characterized by X-ray diffraction and scanning electron microscopy. The thickness of the ZSM-5 coatings could be varied depending on the synthesis conditions. Besides providing the opportunity of manipulating coating properties, the method is also beneficial in respect to the synthesis duration as compared to the conventional procedures.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Substrate heating method for coating metal surfaces with high-silica zeolites: ZSM-5 coatings on stainless steel plates

Tatlıer¹,

Demir²,

Tokay³

et al. 2007

Microporous and Mesoporous Materials

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“…Regarding the relevant developments of the crystallization technique, silica gels were reportedly used in crystal growth in the form of silicate gels 15,16 . However, its application to evaporation techniques has been very limited, probably owing to difficulties in controlling the process required to avoid overdehydration of solution and a dried drop.…”

Section: Discussionmentioning

confidence: 99%

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Vongsvivut¹,

Watanabe

Noda

et al. 2008

ScienceAsia

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ABSTRACT:We have introduced an in-situ Raman monitoring technique to investigate the crystallization process inside protein drops. In addition to a conventional vapour-diffusion process, a novel procedure which actively stimulates the evaporation from a protein drop during crystallization was also evaluated, with lysozyme as a model protein. In contrast to the conventional vapour-diffusion condition, the evaporation-stimulated growth of crystals was initiated in a simple dehydration scheme and completed within a significantly shorter time. To gain an understanding of crystallization behaviours under the conditions with and without such evaporation stimulation, confocal Raman spectroscopy combined with linear regression analysis was used to monitor both lysozyme and HEPES buffer concentrations in real time. The confocal measurements having a high spatial resolution and good linear response revealed areas of local inhomogeneity in protein concentration when the crystallization started. The acquired concentration profiles indicated that (1) the evaporationstimulated crystallization proceeded with protein concentrations lower than those under conventional vapour diffusion, and (2) crystals under the evaporation-stimulated condition were noticeable within an early stage of crystallization before the protein concentration approached its maximum value. The HEPES concentration profiles, on the other hand, increased steadily towards the end of the process regardless of the conditions used for crystallization. In particular, the observed local inhomogeneities specific to protein distribution suggested an accumulation mechanism of protein molecules that initiates the nucleation of crystals.

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“…It has been known that MFI-type zeolites with various crystal shapes can be prepared, such as spherical, hexagonal twined disk, rodlike, and so on [53][54][55][56][57][58][59][60][61][62][63][64][65][66][67][68]. In the synthesis of Al-MFI, the various factors influencing the dimensions along each axis of the crystal have been investigated systematically [69]. The dependence of metal cations, structure-directing agents, chemical source, and compositions has been summarized by Singh and Dutta [70].…”

Section: Morphology Control Of Mfi Zeolite Particles (Of Size Less Thmentioning

confidence: 99%

Morphological Synthesis of Zeolites

Park¹,

Jiang²

2010

Zeolites and Catalysis

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IntroductionZeolites are crystalline inorganic materials with unique, characteristic micropores. These micropores in molecular scale, which have one to three dimensions, are due to interconnected cavities or channels. The types of assembly of cavities or channels control the size of micropores, orientation of microporous channels, and the morphology of zeolite particles. Undoubtedly, the morphology is originally related to the framework type and also closely related to the micropore size, crystal size, and shape, and directly affects the physicochemical properties of zeolites.Zeolites are extensively used in the fields of heterogeneous catalysis, separations, ion exchange, chemical separation, adsorption, host/guest chemistry, microelectronic devices, optics, and membranes [1][2][3][4]. Such applications of zeolites are strongly affected by the pore size, type of channels, and morphologies [5-9]. Morphological synthesis of zeolites is particularly important in catalytic applications where the particle shape can have a dramatic effect on the product distribution due to differences in rates of transport/diffusion and reaction. Recent research interests have also been directed toward the crystallography of single zeolite crystals by applying nanotechnology. Thus, there has been a great interest in developing synthetic approaches to control crystal size and morphology of zeolites [9][10][11].Fine-tuning of zeolite crystal size and shape is usually accomplished by systematic variation of the composition of the precursor mixture (including the use of additives such as salts) [12]. But through the development of new technology and equipment, synthetic parameters such as temperature, pressure, and stirring rate or even gravity can be controlled.This chapter provides a brief introduction to the morphological synthesis of zeolites and related fabrication methods such as as microwave. Examples in the preparation of well-shaped single crystals, fine control of common particles, and microwave driven fabrication are discussed.

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Crystallization and crystal morphology of silicalite-1 prepared from silica gel using different amines as a base

Cited by 30 publications

References 28 publications

Substrate heating method for coating metal surfaces with high-silica zeolites: ZSM-5 coatings on stainless steel plates

Substrate heating method for coating metal surfaces with high-silica zeolites: ZSM-5 coatings on stainless steel plates

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Morphological Synthesis of Zeolites

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