Baalousha, M

Cole, PA

Fernandes, TF

Hriljac, JA

Jepson, MA

Jones, IP

Ju-Nam, Y

Lead, JR

Stone, V

Tyler, CR

Part 1 of the present study discussed the application of a multi-method approach in characterizing the size of cerium oxide nanoparticles (NPs) (see companion paper by Baalousha et al). However, other properties less routinely investigated such as shape and morphology, structure, chemical composition, and surface properties are likely to play an important role in determining the behavior, reactivity, and potential toxicity of these NPs. In the present study, the authors describe the measurement of the aforementioned physicochemical properties of NPs (applied also to nanomaterials [NMs]) compared to micron particles (MPs). They use a wide range of techniques, including high resolution-transmission electron microscopy, scanning electron microscopy, atomic force microscopy, X-ray diffraction, X-ray energy dispersive spectroscopy, electron energy loss spectroscopy, X-ray photoelectron spectroscopy, and electrophoresis. The authors compare these techniques, their advantages, and limitations along with recommendations about how best to approach NM characterization, using an application to commercial cerium oxide NPs and MPs. Results show that both cerium oxide NPs and MPs are formed of single polyhedron or truncated polyhedron crystals. Cerium oxide NPs contain a mixture of Ce(3+) and Ce(4+) cations, whereas the MPs contain mainly Ce(4+) potentially important in understanding toxicity of cerium oxide NPs. The isoelectric point of cerium oxide NPs was approximately pH 8, which explains their propensity to aggregate in aqueous media (see compantion paper by Baalousha et al.). Environ. Toxicol. Chem. © 2012 SETAC

Baalousha, Mohamed

Ju-Nam, Yon

Cole, Paula

Hriljac, Joseph

Jones, Ian

Lead, Jamie

University of Birmingham Research Portal

Characterization of cerium oxide nanoparticles—Part 2 : nonsize measurements

Mohammed Baalousha

Yon Ju-Nam

Paula A. Cole

Joseph A. Hriljac

Ian P. Jones

Charles R. Tyler

Vicki Stone

Teresa F. Fernandes

Mark A. Jepson

Jamie R. Lead

Crossref

Environmental Toxicology and Chemistry

Characterization of cerium oxide nanoparticles-Part 2: Nonsize measurements

Cronfa at Swansea University

Characterization of cerium oxide nanoparticles-Part 1: Size measurements

The present study gives an overview of some of the major aspects for consideration in the characterization of nanomaterials (NMs). Part 1 focuses on the measurement of particle size and size-related parameters using several analytical techniques such as transmission electron microscopy, atomic force microscopy, dynamic light scattering, X-ray diffraction, and Brunauer, Emmett, and Teller surface area measurements as applied to commercially available cerium oxide nanoparticles (NPs) and microparticles (MPs). Part 2 (see companion paper) considers nonsize-related characterization and analysis. The results are discussed in relation to the nature of the sample and preparation, and the analytical principles, limitations, and advantages of each technique. Accurate information on the particle size of the different fractions of a sample can be obtained by using a combination of different types of microscopy, spectroscopy, separation, and other techniques; this should inform ecotoxicological and environmental studies. The good agreement between the measured primary particle size of the NPs (similar to 15 nm) by atomic force microscopy, transmission electron microscopy, X-ray diffraction, and Brunauer, Emmett, and Teller suggests that the primary particles are formed of semispherical single crystals. For MPs, all measurements agree that they are large particles in the range above the NPs (100 nm), with some difference between the measured sizes, possibly as a result of polydispersity effects. Additionally, our findings suggest that atomic force microscopy and transmission electron microscopy prepared by centrifugation methods provide consistent data at low concentrations when dynamic light scattering fails. Environ. Toxicol. Chem. 2012; 31: 983993. (c) 2012 SETA

Gaiser, B

The present study gives an overview of some of the major aspects for consideration in the characterization of NMs in perspective of their properties. Part 1 focuses on the measurement of particle size and size-related parameters using several analytical techniques such as transmission electron microscopy (TEM), atomic force microscopy (AFM), dynamic light scattering (DLS), Xray diffraction (XRD), and Brunauer, Emmett and Teller (BET) surface area measurements as applied to a commercially available cerium oxide nanoparticles (NPs) and microparticles (MPs). Part 2 (see companion paper by Baalousha et al) considers non-size related characterization and analysis. The results are discussed in relation to the sample nature and preparation and the analytical principles, limitations, and advantages of each technique. Accurate information on the particle size of the different fractions of a sample can be obtained using a combination of different microscopy, spectroscopy, separation, and other techniques; this should inform ecotoxicological and environmental studies. The good agreement between the measured primary particle size of the NPs (~15 nm) by AFM, TEM, XRD, and BET suggests that the primary particles are formed of semi-spherical single crystals. For MPs, all measurements agree that they are large particles in the range above the NPs (&gt;100), with some difference between the measured sizes, possibly due to polydispersity effects. Additionally, our findings suggest that AFM and TEM prepared by centrifugation method provide consistent data at low concentrations where DLS fails.The present study gives an overview of some of the major aspects for consideration in the characterization of NMs in perspective of their properties. Part 1 focuses on the measurement of particle size and size-related parameters using several analytical techniques such as transmission electron microscopy (TEM), atomic force microscopy (AFM), dynamic light scattering (DLS), Xray diffraction (XRD), and Brunauer, Emmett and Teller (BET) surface area measurements as applied to a commercially available cerium oxide nanoparticles (NPs) and microparticles (MPs). Part 2 (see companion paper by Baalousha et al) considers non-size related characterization and analysis. The results are discussed in relation to the sample nature and preparation and the analytical principles, limitations, and advantages of each technique. Accurate information on the particle size of the different fractions of a sample can be obtained using a combination of different microscopy, spectroscopy, separation, and other techniques; this should inform ecotoxicological and environmental studies. The good agreement between the measured primary particle size of the NPs (~15 nm) by AFM, TEM, XRD, and BET suggests that the primary particles are formed of semi-spherical single crystals. For MPs, all measurements agree that they are large particles in the range above the NPs (&gt;100), with some difference between the measured sizes, possibly due to polydispersity effects. Additionally, our findings suggest that AFM and TEM prepared by centrifugation method provide consistent data at low concentrations where DLS fails

Explore Bristol Research

Characterization of cerium oxide nanoparticles. Part 1: Size measurements

Birgit Gaiser

Part 1 (see companion paper) of the present study discussed the application of a multimethod approach in characterizing the size of cerium oxide nanoparticles (NPs). However, other properties less routinely investigated, such as shape and morphology, structure, chemical composition, and surface properties, are likely to play an important role in determining the behavior, reactivity, and potential toxicity of these NPs. The present study describes the measurement of the aforementioned physicochemical properties of NPs (applied also to nanomaterials [NMs]) compared with micrometer particles (MPs). The authors use a wide range of techniques, including high resolution-transmission electron microscopy, scanning electron microscopy, atomic force microscopy, X-ray diffraction, X-ray energy dispersive spectroscopy, electron energy loss spectroscopy, X-ray photoelectron spectroscopy, and electrophoresis, and compare these techniques, their advantages, and their limitations, along with recommendations about how best to approach NM characterization, using an application to commercial cerium oxide NPs and MPs. Results show that both cerium oxide NPs and MPs are formed of single polyhedron or truncated polyhedron crystals. Cerium oxide NPs contain a mixture of Ce3+ and Ce4+ cations, whereas the MPs contain mainly Ce4+, which is potentially important in understanding the toxicity of cerium oxide NPs. The isoelectric point of cerium oxide NPs was approximately pH 8, which explains their propensity to aggregate in aqueous media (see companion paper). Environ. Toxicol. Chem. 2012; 31: 9941003. (c) 2012 SETAC</p

Baalousha, Mohammed

Cole, Paula A.

Hriljac, Joseph A.

Jones, Ian P.

Tyler, Charles R.

Stone, Vicki

Fernandes, Teresa F.

Jepson, Mark A.

Lead, Jamie R.

Heriot Watt Pure

Characterization of cerium oxide nanoparticles - part 2: nonsize measurements

Part 1 of the present study discussed the application of a multi-method approach in characterizing the size of cerium oxide nanoparticles (NPs) (see companion paper by Baalousha et al). However, other properties less routinely investigated such as shape and morphology, structure, chemical composition, and surface properties are likely to play an important role in determining the behavior, reactivity, and potential toxicity of these NPs. In the present study, the authors describe the measurement of the aforementioned physicochemical properties of NPs (applied also to nanomaterials [NMs]) compared to micron particles (MPs). They use a wide range of techniques, including high resolution-transmission electron microscopy, scanning electron microscopy, atomic force microscopy, X-ray diffraction, X-ray energy dispersive spectroscopy, electron energy loss spectroscopy, X-ray photoelectron spectroscopy, and electrophoresis. The authors compare these techniques, their advantages, and limitations along with recommendations about how best to approach NM characterization, using an application to commercial cerium oxide NPs and MPs. Results show that both cerium oxide NPs and MPs are formed of single polyhedron or truncated polyhedron crystals. Cerium oxide NPs contain a mixture of Ce3+ and Ce4+ cations, whereas the MPs contain mainly Ce4+ potentially important in understanding toxicity of cerium oxide NPs. The isoelectric point of cerium oxide NPs was approximately pH 8, which explains their propensity to aggregate in aqueous media (see compantion paper by Baalousha et al.).Part 1 of the present study discussed the application of a multi-method approach in characterizing the size of cerium oxide nanoparticles (NPs) (see companion paper by Baalousha et al). However, other properties less routinely investigated such as shape and morphology, structure, chemical composition, and surface properties are likely to play an important role in determining the behavior, reactivity, and potential toxicity of these NPs. In the present study, the authors describe the measurement of the aforementioned physicochemical properties of NPs (applied also to nanomaterials [NMs]) compared to micron particles (MPs). They use a wide range of techniques, including high resolution-transmission electron microscopy, scanning electron microscopy, atomic force microscopy, X-ray diffraction, X-ray energy dispersive spectroscopy, electron energy loss spectroscopy, X-ray photoelectron spectroscopy, and electrophoresis. The authors compare these techniques, their advantages, and limitations along with recommendations about how best to approach NM characterization, using an application to commercial cerium oxide NPs and MPs. Results show that both cerium oxide NPs and MPs are formed of single polyhedron or truncated polyhedron crystals. Cerium oxide NPs contain a mixture of Ce3+ and Ce4+ cations, whereas the MPs contain mainly Ce4+ potentially important in understanding toxicity of cerium oxide NPs. The isoelectric point of cerium oxide NPs was approximately pH 8, which explains their propensity to aggregate in aqueous media (see compantion paper by Baalousha et al.)

Characterization of cerium oxide nanoparticles. Part 2: Nonsize measurements