ASTM D5357-03
(Test Method)Standard Test Method for Determination of Relative Crystallinity of Zeolite Sodium A by X-Ray Diffraction
Standard Test Method for Determination of Relative Crystallinity of Zeolite Sodium A by X-Ray Diffraction
SIGNIFICANCE AND USE
Zeolite NaA has been used as an active component in molecular sieves employed as desiccants for natural gas, process gas streams, sealed insulated windows, and as a builder (water softener) in household laundry detergents.
This X-ray procedure is designed to allow a reporting of the relative degree of crystallization of NaA in the manufacture of NaA. The relative crystallinity number has proven useful in technology, research, and specifications.
Drastic changes in intensity of individual peaks in the XRD pattern of NaA can result from changes in distribution of electron density within the unit cell of the NaA zeolite. The electron density distribution is dependent upon the extent of filling of pores in the zeolite with guest molecules, and on the nature of the guest molecules. In this XRD method, the guest molecule H2O completely fills the pores. Intensity changes may also result if some or all of the sodium cations in NaA are exchanged by other cations.
Drastic changes in overall intensity can result from changes in X-ray absorption attributed to non-crystalline phases, if present, in a NaA sample. If non-zeolite crystalline phases are present, their diffraction peaks may overlap with some of the NaA diffraction peaks selected for this test method. If there is reason to suspect the presence of such components, then NaA peaks free of interference should be chosen for analysis.
SCOPE
1.1 This test method covers a procedure for determining the relative crystallinity of zeolite sodium A (zeolite NaA) using selected peaks from the X-ray diffraction pattern of the zeolite.
1.2 The term "intensity of an X-ray powder diffraction (XRD) peak" refers to the "integral intensity," either the area of counts under the peak or the product of the peak height and the peak width at half height.
1.3 This test method provides a number that is the ratio of intensity of portions of the XRD pattern of the sample to intensity of the corresponding portion of the pattern of a reference zeolite NaA. The intensity ratio, expressed as a percentage, is then labeled "% XRD intensity/NaA."
1.4 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation:D5357–03
Standard Test Method for
Determination of Relative Crystallinity of Zeolite Sodium A
1
by X-ray Diffraction
This standard is issued under the fixed designation D 5357; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope intensities of six strong peaks in the 11–32° 2u range is made,
giving relative crystallinity of NaA.This type of comparison is
1.1 This test method covers a procedure for determining the
commonlyusedinzeolitetechnologyandisoftenreferredtoas
relative crystallinity of zeolite sodium A (zeolite NaA) using
“% crystallinity.”
selected peaks from the X-ray diffraction pattern of the zeolite.
1.2 The term “intensity of an X-ray powder diffraction
4. Significance and Use
(XRD)peak”referstothe“integralintensity,”eithertheareaor
4.1 Zeolite NaA has been used as an active component in
counts under the peak or the product of the peak height and the
molecular sieves employed as desiccants for natural gas,
peak width at half height.
processgasstreams,sealedinsulatedwindows,andasabuilder
1.3 This test method provides a number that is the ratio of
(water softener) in household laundry detergents.
intensity of portions of the XRD pattern of the sample to
4.2 This X-ray procedure is designed to allow a reporting of
intensity of the corresponding portion of the pattern of a
the relative degree of crystallization of NaAin the manufacture
reference zeolite NaA. The intensity ratio, expressed as a
of NaA. The relative crystallinity number has proven useful in
percentage, is then labeled relative crystallinity of NaA.
technology, research, and specifications.
1.4 This standard does not purport to address all of the
4.3 Drastic changes in intensity of individual peaks in the
safety concerns, if any, associated with its use. It is the
XRD pattern of NaAcan result from changes in distribution of
responsibility of the user of this standard to establish appro-
electron density within the unit cell of the NaA zeolite. The
priate safety and health practices and determine the applica-
electron density distribution is dependent upon the extent of
bility of regulatory limitations prior to use.
filling of pores in the zeolite with guest molecules, and on the
2. Referenced Documents nature of the guest molecules. In this XRD method, the guest
molecule H O completely fills the pores. Intensity changes
2
2.1 ASTM Standards:
may also result if some or all of the sodium cations in NaAare
D 3906 Test Method for Determination of Relative X-ray
exchanged by other cations.
Diffraction Intensities of Faujasite-Type Zeolite-
2 4.4 Drastic changes in overall intensity can result from
Containing Materials
changes in X-ray absorption attributed to non-crystalline
E 177 Practice for Use of the Terms Precision and Bias in
3 phases, if present, in a NaA sample. If non-zeolite crystalline
ASTM Test Methods
3
phases are present, their diffraction peaks may overlap with
E 456 Terminology Relating to Quality and Statistics
someoftheNaAdiffractionpeaksselectedforthistestmethod.
E 691 Practice for Conducting an Interlaboratory Study to
3
If there is reason to suspect the presence of such components,
Determine the Precision of a Test Method
then NaA peaks free of interference should be chosen for
3. Summary of Test Method
analysis.
3.1 The XRD patterns of the zeolite NaA or zeolite NaA-
5. Apparatus
containing sample and the reference sample (NaA) are ob-
5.1 X–ray Diffractometer, equipped with computerized data
tained under the same conditions.Acomparison of the sums of
acquisition and reduction capability or with a strip chart
recorder, and using copper K-alpha radiation.
1
This test method is under the jurisdiction of ASTM Committee D32 on 5.2 Drying Oven, set at 100°C.
Catalysts and is the direct responsibility of Subcommittee D32.05 on Zeolites.
5.3 Hydrator (Laboratory Desiccator), maintained at about
Current edition approved March 10, 2003. Published April 2003. Originally
58 % relative humidity by a saturated solution of sodium
approved in 1993. Last previous edition approved in 1998 as D 5357-98.
2
bromide, NaBr.
Annual Book of ASTM Standards, Vol 05.05.
3
Annual Book of ASTM Standards, Vol 14.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D5357–03
FIG. 1 X-Ray Diffraction Pattern of Zeolite NaA—ASTM Sample Z-02
5.4 Planimeter or Appropriate Peak Profile Analysis or
hkl index d (Angstrom) °2u (Cu K-a radiation)
222 7.104 12.46
Digital Integration Software, if diffractometer is
...
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