ASTM E2490-09(2021)

Standard Guide for Measurement of Particle Size Distribution of Nanomaterials in Suspension by Photon Correlation Spectroscopy (PCS)

SIGNIFICANCE AND USE
5.1 PCS is one of the very few techniques that are able to deal with the measurement of particle size distribution in the nano-size region. This guide highlights this light scattering technique, generally applicable in the particle size range from the sub-nm region until the onset of sedimentation in the sample. The PCS technique is usually applied to slurries or suspensions of solid material in a liquid carrier. It is a first principles method (that is, calibration in the standard understanding of this word, is not involved). The measurement is hydrodynamically based and therefore provides size information in the suspending medium (typically water). Thus the hydrodynamic diameter will almost certainly differ from other size diameters isolated by other techniques and users of the PCS technique need to be aware of the distinction of the various descriptors of particle diameter before making comparisons between techniques. Notwithstanding the preceding sentence, the technique is widely applied in industry and academia as both a research and development tool and as a QC method for the characterization of submicron systems.
SCOPE
1.1 This guide deals with the measurement of particle size distribution of suspended particles, which are solely or predominantly sub-100 nm, using the photon correlation (PCS) technique. It does not provide a complete measurement methodology for any specific nanomaterial, but provides a general overview and guide as to the methodology that should be followed for good practice, along with potential pitfalls.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Jan-2021
• ICS: 71.100.01 - Products of the chemical industry in general
• Technical Committee: E56 - Nanotechnology
• Drafting Committee: E56.02 - Physical and Chemical Characterization

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E2490 − 09 (Reapproved 2021)
Standard Guide for
Measurement of Particle Size Distribution of Nanomaterials
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in Suspension by Photon Correlation Spectroscopy (PCS)
This standard is issued under the fixed designation E2490; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
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1. Scope 2.2 ISO Standards:
ISO 13320-1Particle size analysis — Laser diffraction
1.1 This guide deals with the measurement of particle size
methods — Part 1: general principles
distribution of suspended particles, which are solely or pre-
ISO 14488Particulate material — Sampling and sample
dominantly sub-100 nm, using the photon correlation (PCS)
splitting for the determination of particulate properties
technique. It does not provide a complete measurement meth-
ISO 13321Particle size analysis — Photon correlation
odology for any specific nanomaterial, but provides a general
spectroscopy
overview and guide as to the methodology that should be
followed for good practice, along with potential pitfalls.
3. Terminology
1.2 The values stated in SI units are to be regarded as
3.1 Definitions of Terms Specific to This Standard:
standard. No other units of measurement are included in this
3.1.1 Some of the definitions in 3.1 will differ slightly from
standard.
those used within other (non-particle sizing) standards (for
1.3 This standard does not purport to address all of the
example, repeatability, reproducibility). For the purposes of
safety concerns, if any, associated with its use. It is the
this guide only, we utilize the stated definitions, as they enable
responsibility of the user of this standard to establish appro-
the isolation of possible errors or differences in the measure-
priate safety, health, and environmental practices and deter-
ment to be assigned to instrumental, dispersion or sampling
mine the applicability of regulatory limitations prior to use.
variation.
1.4 This international standard was developed in accor-
3.1.2 correlation coeffıcient, n—measure of the correlation
dance with internationally recognized principles on standard-
(or similarity/comparison) between 2 signals or a signal and
ization established in the Decision on Principles for the
itself at another point in time.
Development of International Standards, Guides and Recom-
3.1.2.1 Discussion—If there is perfect correlation (the sig-
mendations issued by the World Trade Organization Technical
nals are identical), then this takes the value 1.00; with no
Barriers to Trade (TBT) Committee.
correlation then the value is zero.
3.1.3 correlogram or correlation function, n—graphicalrep-
2. Referenced Documents
resentation of the correlation coefficient over time.
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2.1 ASTM Standards:
3.1.3.1 Discussion—This is typically an exponential decay.
E177Practice for Use of the Terms Precision and Bias in
3.1.4 cumulants analysis, n—mathematical fitting of the
ASTM Test Methods
correlation function as a polynomial expansion that produces
E691Practice for Conducting an Interlaboratory Study to
some estimate of the width of the particle size distribution.
Determine the Precision of a Test Method
3.1.5 diffusion coeffıcient (self or collective), n—a measure
E1617Practice for Reporting Particle Size Characterization
of the Brownian motion movement of a particle(s) in a
Data
medium.
F1877Practice for Characterization of Particles
3.1.5.1 Discussion—After measurement, the value is be
inputted into in the Stokes-Einstein equation (Eq 1, see
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This guide is under the jurisdiction of ASTM Committee E56 on Nanotech-
7.2.1.2(4)). Diffusion coefficient units in photon correlation
nology and is the direct responsibility of Subcommittee E56.02 on Physical and 2
spectroscopy (PCS) measurements are typically µm /s.
Chemical Characterization.
Current edition approved Feb. 1, 2021. Published February 2021. Originally
3.1.6 Mie region, n—in this region (typically where the size
approved in 2008. Last previous edition in 2015 as E2490–09 (2015). DOI:
of the particle is greater than half the wavelength of incident
10.1520/E2490-09R21.
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
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the ASTM website. 4th Floor, New York, NY 10036, http://www.ansi.org.
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