1、Designation: D 4464 00 (Reapproved 2005)Standard Test Method forParticle Size Distribution of Catalytic Material by Laser LightScattering1This standard is issued under the fixed designation D 4464; the number immediately following the designation indicates the year oforiginal adoption or, in the cas
2、e of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the particlesize distribution of catalyst and
3、 catalyst carrier particles and isone of several found valuable for the measurement of particlesize. The range of particle sizes investigated was 30 to 300 mequivalent spherical diameter. The technique is capable ofmeasuring particles above and below this range. The angle andintensity of laser light
4、 scattered by the particles are selectivelymeasured to permit calculation of a volume distribution usinglight-scattering techniques.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establ
5、ish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 3766 Terminology Relating to Catalysts and CatalysisE 105 Practice for Probability Sampling of MaterialsE 177 Practice for Use of the Term
6、s Precision and Bias inASTM Test MethodsE 456 Terminology Relating to Quality and StatisticsE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE 1617 Practice for Reporting Particle Size Characteriza-tion Data3. Terminology3.1 Definitions and recommended
7、 nomenclature pertainingto catalysts and to materials used in their manufacture can befound in Terminology D 3766.3.2 Definitions of Terms Specific to This Standard:3.2.1 backgroundextraneous scattering of light by mate-rial present in the dispersion fluid other than the particles to bemeasured. It
8、includes scattering by contamination in themeasurement path.3.2.2 Fraunhofer Diffractionthe optical theory that de-scribes the low-angle scattering of light by particles that arelarge compared to the wavelength of the incident light.3.2.3 Mie Scatteringthe complex electromagnetic theorythat describe
9、s the scattering of light by spherical particles. It isusually applied to particles with diameters that are close to thewavelength of the incident light. The real and imaginaryindices of light refraction of the particles are needed.3.2.4 multiple scatteringthe re-scattering of light by aparticle in
10、the path of light scattered by another particle. Thisusually occurs in heavy concentrations of a particle dispersion.4. Summary of Test Method4.1 Aprepared sample of particulate material is dispersed inwater or a compatible organic liquid and is circulated throughthe path of a laser light beam or so
11、me other suitable source oflight. The particles pass through the light beam and scatter it.Photodetector arrays collect the scattered light which is con-verted to electrical signals to be analyzed using FraunhoferDiffraction, or Mie Scattering, or both. Scattering information,typically, is analyzed
12、assuming a spherical geometry for theparticles. Calculated particle sizes are, therefore, presented asequivalent spherical diameters.5. Significance and Use5.1 It is important to recognize that the results obtained bythis test method or any other method for particle size determi-nation utilizing dif
13、ferent physical principles may disagree. Theresults are strongly influenced by physical principles employedby each method of particle size analysis. The results of anyparticle sizing method should be used only in a relative senseand should not be regarded as absolute when comparing resultsobtained b
14、y other methods.1This test method is under the jurisdiction of ASTM Committee D32 onCatalysts and is the direct responsibility of Subcommittee D32.02 on Physical-Mechanical Properties.Current edition approved Oct. 1, 2005. Published October 2005. Originallyapproved in 1985. Last previous edition app
15、roved in 2000 as D 446400.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100
16、Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.2 Light scattering theories (Fraunhofer Diffraction3andMie Scattering4) that are used for determination of particle sizehas been available for many years. Several manufacturers oftesting equipment now have units based
17、on these principles.Although each type of testing equipment utilizes the samebasic principles for light scattering as a function of particlesize, different assumptions pertinent to application of thetheory and different models for converting light measurementsto particle size, may lead to different
18、results for each instru-ment. Furthermore, any particles which are outside the sizemeasurement range of the instrument will be ignored, causingan increase in the reported percentages within the detectablerange. A particle size distribution which ends abruptly at thedetection limit of the instrument
19、may indicate that particlesoutside the range are present. Therefore, use of this test methodcannot guarantee directly comparable results from differenttypes of instruments.5.3 This test method can be used to determine particle sizedistributions of catalysts and supports for materials specifica-tions
20、, manufacturing control, and research and developmentwork.6. Interferences6.1 Air bubbles entrained in the circulating fluid will scatterlight and then be reported as particles. Circulating fluids,typically, do not require degassing, but should be bubble-freeon visual inspections.6.2 Contaminants, s
21、uch as non-aqueous solvents, oil orother organic coatings on the sample may emulsify in anaqueous carrier, scatter light, and be reported as part of theparticle size distribution. Samples containing such contami-nants may be analyzed in a non-aqueous carrier solvent todissolve the contaminants or wa
22、shed free of the contaminantwith a compatible aqueous solvent.6.3 Reagglomeration or settling of particles during analysiswill cause erroneous results. Dispersions shall be prepared so astable dispersion is maintained throughout the analysis.6.4 Insufficient sample loading may cause electrical noise
23、interference and poor data reproducibility. High sample load-ing may cause excessive light attenuation and multiple scatter-ing, resulting in erroneous particle size distributions.7. Apparatus7.1 Particle Size Analyzer, based on Fraunhofer Diffractionor Mie Scattering, or both, light scattering anal
24、ysis techniques.Ensure that the analyzer system or subsystem is optimum forthe range of the powder being tested.7.2 Micro Sample Splitter, used in accordance withMNL 325to obtain the test portion of sample.7.3 Ultrasonic Probe or Bath, if needed, to ensure disper-sion of agglomerates prior to analys
25、is.8. Reagents and Materials8.1 The selected liquid carrier shall:8.1.1 Be compatible with the construction materials of thesample delivery system.8.1.2 Not cause dissolution or clumping of the particles.8.1.3 Be sufficiently clean to achieve acceptable backgroundlevels.8.2 The use of surfactant(s)
26、is often recommended byequipment manufacturers. However, agents such as surfactants,antifoams, and viscosity modifiers should be used with caution.An interlaboratory study of this test method showed that theuse of different types and concentrations of surfactant cansignificantly affect the results.
27、In calculating the precision ofthis test method, results obtained using surfactants wereexcluded because they contributed disproportionately to thescatter in results. Comparisons between laboratories should beperformed with liquid carriers which are identical in allrespects.9. Sampling and Sample Si
28、ze9.1 A representative test sample shall be obtained accordingto Practice E 105. The test portion shall be extracted from thetest sample using a micro sample splitter according toMNL 32.5Quartering shall not be used.9.2 Refer to the equipment manufacturers recommendationto ensure that the amount of
29、the test portion is acceptable toachieve optimum light scattering conditions. A wide range ofsample portions is acceptable depending upon median particlesize, particle density, and the sample delivery system.9.3 For liquid dispersed materials, redisperse as necessaryto ensure representative samples.
30、10. Preparation of Apparatus10.1 Allow the instrument to warm up according to themanufacturers recommendations.10.2 Install and fill the desired sample delivery system andselect applicable instrument range as indicated by the instru-ment manufacturers instructions.10.3 Establish correct optical alig
31、nment and calibration at afrequency in accordance with the manufacturers requirements.11. Calibration and Standardization11.1 Performance of the instrument is defined by the geom-etry of the optical components. (Refer to the manufacturersinstruction manual.)11.2 Spherical particle standards are avai
32、lable. Diagnosticpowders are available from some equipment manufacturers toensure consistent instrument function. (Some instruments maypermit the use of reticles for calibration.)NOTE 1A partial list of standards, powders, and reticles can be foundin RR:D32-1013.612. Procedure12.1 Measure the backgr
33、ound in the mode in which theanalysis will be carried out. Be sure that the carrier is flowing3Born, M., and Wolf, E., Principles of Optics, Chapter 8, Pergamon Press,Oxford, 1957.4van Hulst, H.C., Light Scattering by Small Particles, Chapter 9, John Wiley Fraunhofer Diffraction; light scattering; M
34、ieScatteringASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such
35、 rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additi
36、onal standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the
37、ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the a
38、boveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).TABLE 1 PrecisionFraction SmallerThan (FST)Consensus MedianDiameter, mRepeatability ReproducibilityD329500110 volume % 37.11 0.61 (1.65 %) 4.66 (12.5 %)50 volume % 68.04
39、 1.18 (1.74 %) 2.85 (4.19 %)90 volume % 120.6 3.59 (2.98 %) 9.66 (8.01 %)D329100310 volume % 39.71 1.91 (4.81 %) 8.59 (21.6 %)50 volume % 83.28 3.13 (3.76 %) 7.49 (8.99 %)90 volume % 153.2 6.82 (4.45 %) 16.31 (10.7 %)D329500310 volume % 57.78 5.53 (9.57 %) 12.30 (21.3 %)50 volume % 140.4 9.70 (6.91 %) 16.38 (11.7 %)90 volume % 254.6 17.53 (6.88 %) 53.82 (21.1 %)D 4464 00 (2005)3
