Chemical Analysis of Aluminosilicates, Aluminophosphates and Related Molecular Sieves

Kosslick, H.; Fricke, R.

doi:10.1007/3829_001

Cited by 5 publications

(4 citation statements)

References 67 publications

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“…A shift in the position of the Si-O band maximum as well as a broadening of the peak can be observed. The related literature [45,67] reports a shift in this band to smaller wave numbers depending on the silicon content in the aluminosilicate structure. The dependence of the wave number (Table 8) on the silicon content (Table 7) is elaborated in Figure 8a.…”

Section: Changes Of Mk Ammentioning

confidence: 77%

Reactivity of Metakaolin in Alkaline Environment: Correlation of Results from Dissolution Experiments with XRD Quantifications

et al. 2020

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Systematic investigation of filtrates and filter residues resulting from a 24 h treatment of metakaolin in different alkaline solutions were performed. On filtered metakaolin particles, inductively coupled plasma-optical emission spectrometry (ICP-OES) measurements reveal an enrichment of iron and titanium, which suggests an inhomogeneous distribution of these cations. Since the SiO2/Al2O3 ratio remains constant in all filter residues examined, the dissolution of the Si and Al monomers is congruent. Structural differences, identified by attenuated total reflection–Fourier transform infrared spectroscopy (ATR-FTIR) as a consequence of alkali uptake, influence the X-ray scattering contribution of metakaolin, and thus quantifications with the partial or no known crystal structure (PONKCS) method. This leads to deviations between the degree of reaction calculated from Si and Al solubility from filtrate and that quantified by quantitative powder X-ray diffraction (QPXRD) using the filter residue. Nevertheless, the described changes do not cause a shift in the X-ray amorphous hump in case of congruent dissolution, and thus allow the quantification of the metakaolin before and after dissolution with the same hkl-phase model.

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Section: Changes Of Mk Ammentioning

confidence: 77%

Reactivity of Metakaolin in Alkaline Environment: Correlation of Results from Dissolution Experiments with XRD Quantifications

et al. 2020

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“…Uncertainties in the Si/Al ratio as high as ±6 have been reported for zeolites with comparable Al content . Other reports tend to use only qualitative comparisons when analyzing XPS data of zeolites with low elemental percentages of Al . To this end, the quantitative degree of zoning in core (ZSM-5) particles cannot be conclusively determined from the XPS data.…”

Section: Resultsmentioning

confidence: 99%

Epitaxial Growth of ZSM-5@Silicalite-1: A Core–Shell Zeolite Designed with Passivated Surface Acidity

et al. 2015

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The design of materials with spatially controlled chemical composition has potential advantages for wide-reaching applications that span energy to medicine. Here, we present a method for preparing a core-shell aluminosilicate zeolite with continuous translational symmetry of nanopores and an epitaxial shell of tunable thickness that passivates Brønsted acid sites associated with framework Al on exterior surfaces. For this study, we selected the commercially relevant MFI framework type and prepared core-shell particles consisting of an aluminosilicate core (ZSM-5) and a siliceous shell (silicalite-1). Transmission electron microscopy and gas adsorption studies confirmed that silicalite-1 forms an epitaxial layer on ZSM-5 crystals without blocking pore openings. Scanning electron microscopy and dynamic light scattering were used in combination to confirm that the shell thickness can be tailored with nanometer resolution (e.g., 5-20 nm). X-ray photoelectron spectroscopy and temperature-programmed desorption measurements revealed the presence of a siliceous shell, while probe reactions using molecules that were either too large or adequately sized to access MFI pores confirmed the uniform shell coverage. The synthesis of ZSM-5@silicalite-1 offers a pathway for tailoring the physicochemical properties of MFI-type materials, notably in the area of catalysis, where surface passivation can enhance product selectivity without sacrificing catalyst activity. The method described herein may prove to be a general platform for zeolite core-shell design with potentially broader applicability to other porous materials.

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“…Zirconia beads were also found to increase total DNA detections and species richness (Ushio, 2019). The molecular sieve was included as additive material, even though it is generally used for chromatography to entrap gases (Kosslick & Fricke, 2007) because its rough shape could be expected to be a substrate for DNA attachment that is different from the smooth and circular surface of beads. Bessey et al (2020) investigated how water sample volume affects the detections of species in a fish community by using various water sample volumes from 25 to 2000 ml, and more species were detected as more water was filtered; thus, to examine the factor of sample volume, we compared 2‐L and 10‐L water samples.…”

Section: Introductionmentioning

confidence: 99%

Positive effect of filtration additives for increasing environmental DNA detections in summer and winter oceanic waters

et al. 2022

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Chemical Analysis of Aluminosilicates, Aluminophosphates and Related Molecular Sieves

Cited by 5 publications

References 67 publications

Reactivity of Metakaolin in Alkaline Environment: Correlation of Results from Dissolution Experiments with XRD Quantifications

Reactivity of Metakaolin in Alkaline Environment: Correlation of Results from Dissolution Experiments with XRD Quantifications

Epitaxial Growth of ZSM-5@Silicalite-1: A Core–Shell Zeolite Designed with Passivated Surface Acidity

Positive effect of filtration additives for increasing environmental DNA detections in summer and winter oceanic waters

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