Size and shape distributions of primary crystallites in titania aggregates

Eric A. Grulke, Kazuhiro Yamamoto, Kazuhiro Kumagai, Ines Häusler, Werner Österle, Erik Ortel, Vasile Dan Hodoroaba, Scott C. Brown, Christopher Chan, Jiwen Zheng, Kenji Yamamoto, Kouji Yashiki, Nam Woong Song, Young Heon Kim, Aleksandr B. Stefaniak, D. Schwegler-Berry, Victoria A. Coleman, Åsa K. Jämting, Jan Herrmann, Toru ArakawaWoodrow W. Burchett, Joshua W. Lambert, Arnold J. Stromberg

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


The primary crystallite size of titania powder relates to its properties in a number of applications. Transmission electron microscopy was used in this interlaboratory comparison (ILC) to measure primary crystallite size and shape distributions for a commercial aggregated titania powder. Data of four size descriptors and two shape descriptors were evaluated across nine laboratories. Data repeatability and reproducibility was evaluated by analysis of variance. One-third of the laboratory pairs had similar size descriptor data, but 83% of the pairs had similar aspect ratio data. Scale descriptor distributions were generally unimodal and were well-described by lognormal reference models. Shape descriptor distributions were multi-modal but data visualization plots demonstrated that the Weibull distribution was preferred to the normal distribution. For the equivalent circular diameter size descriptor, measurement uncertainties of the lognormal distribution scale and width parameters were 9.5% and 22%, respectively. For the aspect ratio shape descriptor, the measurement uncertainties of the Weibull distribution scale and width parameters were 7.0% and 26%, respectively. Both measurement uncertainty estimates and data visualizations should be used to analyze size and shape distributions of particles on the nanoscale.

Original languageEnglish
Pages (from-to)1647-1659
Number of pages13
JournalAdvanced Powder Technology
Issue number7
StatePublished - Jul 2017

Bibliographical note

Publisher Copyright:
© 2017


  • Measurement uncertainty
  • Shape distribution
  • Size distribution
  • TEM
  • Titania

ASJC Scopus subject areas

  • General Chemical Engineering
  • Mechanics of Materials


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