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Toward advancing nano-object count metrology: a best practice framework.

Brown SC, Boyko V, Meyers G, Voetz M, Wohlleben W - Environ. Health Perspect. (2013)

Bottom Line: Although particle size remains the sole discriminating factor for classifying a material as "nano," inconsistencies in size metrology will continue to confound policy and decision making.To enable future risk-based refinements of these emerging definitions, we recommend that this framework also be considered in environmental and human health research involving the implications of nanomaterials.Strong cooperation between industry, academia, and research institutions will be required to fully develop and implement detailed frameworks for nanomaterial identification with respect to emerging count-based metrics.

View Article: PubMed Central - PubMed

Affiliation: Corporate Center for Analytical Sciences, DuPont Central Research and Development, Wilmington, Delaware, USA.

ABSTRACT

Background: A movement among international agencies and policy makers to classify industrial materials by their number content of sub-100-nm particles could have broad implications for the development of sustainable nanotechnologies.

Objectives: Here we highlight current particle size metrology challenges faced by the chemical industry due to these emerging number percent content thresholds, provide a suggested best-practice framework for nano-object identification, and identify research needs as a path forward.

Discussion: Harmonized methods for identifying nanomaterials by size and count for many real-world samples do not currently exist. Although particle size remains the sole discriminating factor for classifying a material as "nano," inconsistencies in size metrology will continue to confound policy and decision making. Moreover, there are concerns that the casting of a wide net with still-unproven metrology methods may stifle the development and judicious implementation of sustainable nanotechnologies. Based on the current state of the art, we propose a tiered approach for evaluating materials. To enable future risk-based refinements of these emerging definitions, we recommend that this framework also be considered in environmental and human health research involving the implications of nanomaterials.

Conclusion: Substantial scientific scrutiny is needed in the area of nanomaterial metrology to establish best practices and to develop suitable methods before implementing definitions based solely on number percent nano-object content for regulatory purposes. Strong cooperation between industry, academia, and research institutions will be required to fully develop and implement detailed frameworks for nanomaterial identification with respect to emerging count-based metrics.

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Sources of error in particle size analysis. Reprinted with kind permission from CSC Publishing [Powder and Bulk Engineering. Nanotechnology’s challenges = equipment manufacturers’ opportunities, 20:99–104 (2006). Moudgil BM, Brown SC, Krishna VB] and from Springer+Business Media: Particle Size Measurements: Fundamentals, Practice, Quality. Dispersion of powders in air and in liquids. Springer Particle Technology Series Vol 17. 1st ed. 2009, p. 119, Merkus HG, Figure 5.2. Copyright 2009 Springer Science+Business Media B.V.
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f6: Sources of error in particle size analysis. Reprinted with kind permission from CSC Publishing [Powder and Bulk Engineering. Nanotechnology’s challenges = equipment manufacturers’ opportunities, 20:99–104 (2006). Moudgil BM, Brown SC, Krishna VB] and from Springer+Business Media: Particle Size Measurements: Fundamentals, Practice, Quality. Dispersion of powders in air and in liquids. Springer Particle Technology Series Vol 17. 1st ed. 2009, p. 119, Merkus HG, Figure 5.2. Copyright 2009 Springer Science+Business Media B.V.

Mentions: Advancements in dispersion science and methodology. As particle size decreases, error in size analysis from inadequate dispersion increases (Figure 6) (Moudgil 2006). Although modern understanding of interfacial phenomena and energy transfer involved in dispersion has advanced significantly, it is still not possible to predict the conditions under which a material will be fully dispersed. Further advancements in this area are needed along with improved reporting requirements and procedures to enable adequate reproduction of dispersion between facilities and with differing equipment.


Toward advancing nano-object count metrology: a best practice framework.

Brown SC, Boyko V, Meyers G, Voetz M, Wohlleben W - Environ. Health Perspect. (2013)

Sources of error in particle size analysis. Reprinted with kind permission from CSC Publishing [Powder and Bulk Engineering. Nanotechnology’s challenges = equipment manufacturers’ opportunities, 20:99–104 (2006). Moudgil BM, Brown SC, Krishna VB] and from Springer+Business Media: Particle Size Measurements: Fundamentals, Practice, Quality. Dispersion of powders in air and in liquids. Springer Particle Technology Series Vol 17. 1st ed. 2009, p. 119, Merkus HG, Figure 5.2. Copyright 2009 Springer Science+Business Media B.V.
© Copyright Policy - public-domain
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3852792&req=5

f6: Sources of error in particle size analysis. Reprinted with kind permission from CSC Publishing [Powder and Bulk Engineering. Nanotechnology’s challenges = equipment manufacturers’ opportunities, 20:99–104 (2006). Moudgil BM, Brown SC, Krishna VB] and from Springer+Business Media: Particle Size Measurements: Fundamentals, Practice, Quality. Dispersion of powders in air and in liquids. Springer Particle Technology Series Vol 17. 1st ed. 2009, p. 119, Merkus HG, Figure 5.2. Copyright 2009 Springer Science+Business Media B.V.
Mentions: Advancements in dispersion science and methodology. As particle size decreases, error in size analysis from inadequate dispersion increases (Figure 6) (Moudgil 2006). Although modern understanding of interfacial phenomena and energy transfer involved in dispersion has advanced significantly, it is still not possible to predict the conditions under which a material will be fully dispersed. Further advancements in this area are needed along with improved reporting requirements and procedures to enable adequate reproduction of dispersion between facilities and with differing equipment.

Bottom Line: Although particle size remains the sole discriminating factor for classifying a material as "nano," inconsistencies in size metrology will continue to confound policy and decision making.To enable future risk-based refinements of these emerging definitions, we recommend that this framework also be considered in environmental and human health research involving the implications of nanomaterials.Strong cooperation between industry, academia, and research institutions will be required to fully develop and implement detailed frameworks for nanomaterial identification with respect to emerging count-based metrics.

View Article: PubMed Central - PubMed

Affiliation: Corporate Center for Analytical Sciences, DuPont Central Research and Development, Wilmington, Delaware, USA.

ABSTRACT

Background: A movement among international agencies and policy makers to classify industrial materials by their number content of sub-100-nm particles could have broad implications for the development of sustainable nanotechnologies.

Objectives: Here we highlight current particle size metrology challenges faced by the chemical industry due to these emerging number percent content thresholds, provide a suggested best-practice framework for nano-object identification, and identify research needs as a path forward.

Discussion: Harmonized methods for identifying nanomaterials by size and count for many real-world samples do not currently exist. Although particle size remains the sole discriminating factor for classifying a material as "nano," inconsistencies in size metrology will continue to confound policy and decision making. Moreover, there are concerns that the casting of a wide net with still-unproven metrology methods may stifle the development and judicious implementation of sustainable nanotechnologies. Based on the current state of the art, we propose a tiered approach for evaluating materials. To enable future risk-based refinements of these emerging definitions, we recommend that this framework also be considered in environmental and human health research involving the implications of nanomaterials.

Conclusion: Substantial scientific scrutiny is needed in the area of nanomaterial metrology to establish best practices and to develop suitable methods before implementing definitions based solely on number percent nano-object content for regulatory purposes. Strong cooperation between industry, academia, and research institutions will be required to fully develop and implement detailed frameworks for nanomaterial identification with respect to emerging count-based metrics.

Show MeSH