Homogeneous versus Heterogeneous Zeolite Nucleation

Dokter, WH Wim; Garderen, van Hf; Beelen, Tpm Theo; Santen, van Ra Rutger; Bras, Wim

doi:10.1002/anie.199500731

Cited by 153 publications

(146 citation statements)

References 18 publications

Supporting

Mentioning

138

Contrasting

Unclassified

Order By: Relevance

“…In an earlier study 11 we interpreted this feature as being due to scattering from amorphous colloidal aggregates with a size of around 7 nm. Later 13 we found the formation of this colloidal aggregate to be dependent on the alkalinity of the synthesis mixture: for Si/OH values higher than 2.65 colloidal aggregates are formed, while they are not observed for lower values.…”

Section: Saxs/waxs and Usaxs Resultsmentioning

confidence: 94%

“…We demonstrated earlier that in situ time resolved combined small-and wideangle X-ray scattering can give valuable information on both the long range order and the formation of amorphous colloidal structures. 11 For the synthesis of Si-TPA-MFI from a clear solution we found the formation of amorphous colloidal aggregates (size ∼ 7 nm) prior to the onset of crystallization. As soon as the first signs of MFI-Bragg reflections appeared in the WAXS pattern, changes in the SAXS pattern showed the formation of particles larger than 50 nm.…”

Section: Introductionmentioning

confidence: 89%

See 1 more Smart Citation

In Situ Investigation of Si-TPA-MFI Crystallization Using (Ultra-) Small- and Wide-Angle X-ray Scattering

et al. 1997

Self Cite

View full text Add to dashboard Cite

The formation of precursors and the growth and aggregation of silicalite-1 crystals using tetrapropylammonium as a template (Si-TPA-MFI) has been studied in situ using X-ray scattering techniques. Simultaneous smallangle and wide-angle X-ray scattering (respectively SAXS and WAXS) experiments using synchrotron light showed that the formation of amorphous colloidal aggregates in water clear synthesis mixtures was dependent on the alkalinity of the solutions. In situ time-resolved ultra-small-angle X-ray scattering (USAXS) showed the form factor oscillations of the growing crystals. Fitting of the USAXS patterns to the scattering pattern of spherical particles having a normal particle size distribution showed a linear growth of the average crystal diameter, which was approximately the same for both alkalinities studied. The final size of the crystals was highest for the synthesis mixture having the highest alkalinity, which can be explained in terms of number of viable nuclei formed. At the end of the linear growth the crystals form aggregates corresponding with a diffusion limited aggregation process (mass fractal dimension of 1.8).

show abstract

Section: Saxs/waxs and Usaxs Resultsmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 89%

In Situ Investigation of Si-TPA-MFI Crystallization Using (Ultra-) Small- and Wide-Angle X-ray Scattering

et al. 1997

Self Cite

View full text Add to dashboard Cite

show abstract

“…Nanoparticle and crystal growth then occurs via addition of either elementary particles or primary units. This mechanism is effectively that described in the work of De Moor et al 25,26 and Doktor et al 29 The second scheme describes an 'aggregative growth' mechanism proposed by the group of Tsapatsis (e.g. Davis et al 37 ) as a result of an in-depth room temperature formation study of silicalite-1 (allowing TEM and AFM to be performed 'in situ').…”

Section: Complementary Silicalite-1 Studies and The Nature Of Nanoparmentioning

confidence: 92%

The role of synchrotron radiation in examining the self-assembly of crystalline nanoporous framework materials: from zeolites and aluminophosphates to metal organic hybrids

2010

View full text Add to dashboard Cite

This tutorial review describes the role of synchrotron-based techniques in the study of the formation of Crystalline Nanoporous Framework Materials (CNFMs), such as zeolites, aluminophosphates (AlPOs) and metal organic frameworks (MOFs). Initially, a general formation process for CNFMs is described and the 'tool kit' (including synchrotron and non-synchrotron-based techniques) used to examine this complex process is presented. The need for realistic in situ conditions and the balance between this, data quality and time resolution, are also discussed with reference to commonly utilized in situ synchrotron-based experimental cells. The experimental studies into the formation of several CNFM systems are then examined and the role of the synchrotron-based experiments, in context with those obtained from other techniques, is discussed. From this the importance of the synchrotron-based technique is demonstrated, however it is also shown that, to obtain a more complete understanding of the formation process, complementary independent measurements are still often required. During these discussions some of the most common experimental techniques and analytical methods are also discussed in detail and critically assessed.

show abstract

“…Under variation of these parameters, the initial precursor mixtures can appear as dry solid, dense (viscous) gel, liquid gel, milky suspension, or water clear suspension prior hydrothermal treatment [8][9][10][11]. Almost immediate polymerization and depolymerization processes are occurred, and a possible precipitation can follow.…”

Section: Parameters Governing Zeolite Synthesismentioning

confidence: 99%

Progress in zeolite synthesis promotes advanced applications

Zaarour

Dong

Naydenova³

et al. 2014

Microporous and Mesoporous Materials

156

View full text Add to dashboard Cite

a b s t r a c tThis article outlines the importance of zeolite synthesis and their unique physicochemical characteristics promoting advanced applications. The main strategies for preparation of zeolites including organic-template assisted, organic-template free and alternative procedures are considered for synthesis of crystallites offering control and fine-tuning of their properties. Besides, rational design of zeolites with pre-determined structure, porosity, size, morphology, and composition are more viable by studying carefully the chemical and physical parameters controlling the zeolite synthesis and understanding the crystallization mechanism. Finally, a particular attention to the preparation of zeolites with nanosized dimensions and their utilization in innovative applications including photovoltaic, medicine and holographic sensors are presented.

show abstract

Homogeneous versus Heterogeneous Zeolite Nucleation

Cited by 153 publications

References 18 publications

In Situ Investigation of Si-TPA-MFI Crystallization Using (Ultra-) Small- and Wide-Angle X-ray Scattering

In Situ Investigation of Si-TPA-MFI Crystallization Using (Ultra-) Small- and Wide-Angle X-ray Scattering

The role of synchrotron radiation in examining the self-assembly of crystalline nanoporous framework materials: from zeolites and aluminophosphates to metal organic hybrids

Progress in zeolite synthesis promotes advanced applications

Contact Info

Product

Resources

About