Measurement of the size and density of colloidal particles by combining sedimentation field-flow fractionation and quasi-elastic light scattering

Caldwell, Karin D.; Jones, Harlan K.; Giddings, J. Calvin

doi:10.1016/0166-6622(86)80199-8

Cited by 22 publications

(11 citation statements)

References 8 publications

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“…CeFFF is one of the FFF subtechniques that has been extensively used for separation of nano and micron-sized particles with high resolution. − The separation principle and mechanism of CeFFF are described in detail elsewhere , and will be mentioned only briefly here. In the Brownian (or normal) mode, the particle effective mass ( m ′) is a measurable quantity and can be calculated from retention time t r using eqs and : , where R is the retention ratio, λ is the retention parameter, t 0 is the void time, k is the Boltzmann constant, T is the temperature in Kelvin, G is the centrifugal acceleration, and w is the channel thickness. t 0 is the void time and for constant flow rate runs is given by where V 0 is the channel void volume and V̇ is the volumetric channel flow rate.…”

Section: Theorymentioning

confidence: 99%

“…11−14 The separation principle and mechanism of CeFFF are described in detail elsewhere 13,15 and will be mentioned only briefly here. In the Brownian (or normal) mode, the particle effective mass (m′) is a measurable quantity and can be calculated from retention time t r using eqs 1 and 2: 10,16…”

Section: ■ Theorymentioning

confidence: 99%

“…7−9 The manuscript describes a procedure to measure density of nanoparticles based on the effective mass measured from CeFFF and the volume obtained from transmission electron microscopy (TEM). The procedure is similar to the methodology reported by Caldwell et al, 10 where CeFFF was combined with quasi-elastic light scattering (QELS) to measure the density of polyvinyl chloride (PVC) latex particles with a broad size distribution. In our trials, the size obtained by dynamic light scattering (DLS) was always overestimated by up to 10% compared to TEM results, resulting in an underestimation of nanoparticle density.…”

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confidence: 99%

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Measurement of the Density of Engineered Silver Nanoparticles Using Centrifugal FFF-TEM and Single Particle ICP-MS

et al. 2017

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A methodology has been developed to measure nanoparticle mass and density, by combining centrifugal field-flow fractionation (CeFFF; more commonly called sedimentation FFF or SdFFF) and transmission electron microscopy (TEM). Particle effective mass obtained from CeFFF retention data and particle size obtained from the TEM images were used to calculate the nanoparticle density. The method was initially applied to measure the density of monodispersed polystyrene latex nanoparticles. Measured densities for latex nanoparticles of 160-300 nm in diameter were in the range of 1041-1063 kg m with standard deviations of 0.6-1.1%. Densities of engineered silver nanoparticles with nominal diameters of 30, 60, 75, and 100 nm were measured using this methodology. For all four silver nanoparticle samples, the measured densities were 18-24% lower than the nominal density of metallic silver, with an overall mean value of 7900 ± 675 kg m. Density values calculated using nanoparticle mass values obtained from single particle inductively coupled plasma-mass spectrometry (spICP-MS) measurements, corroborated the CeFFF-TEM results. The difference in the density of the silver nanoparticles compared to that of bulk silver suggests that the synthesis process could impart 20-37% porosity in silver nanoparticles. The data has important implications in the fields of nanomaterial, nanomedicine and nanotoxicology, where assumption of the bulk density for nanoparticles can result in erroneous estimation of parameters such as mass, size, porosity, and dosage. The presented methodology provides a straightforward and reproducible means for measurement of the density and porosity of engineered nanoparticles with a wide range of density and size.

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Section: Theorymentioning

confidence: 99%

Section: ■ Theorymentioning

confidence: 99%

mentioning

confidence: 99%

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Measurement of the Density of Engineered Silver Nanoparticles Using Centrifugal FFF-TEM and Single Particle ICP-MS

et al. 2017

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“…In the physical sciences, applications of particle sizing have included quantifying the aggregation of protein drug products 1 and measuring the volume fraction and size dispersity of colloidal suspensions. 2 In biology, cell size is fundamentally linked to the cell state, and particle sizing tools have been employed both to investigate basic questions about how individual cells regulate their size and growth 3 and for practical applications such as evaluating ex vivo the susceptibility of primary patient tissue to cancer therapeutics. 4 There are several single-particle approaches that are routinely used for sizing particle suspensions in the 5-20 μm size range.…”

Section: Introductionmentioning

confidence: 99%

Rapid and high-precision sizing of single particles using parallel suspended microchannel resonator arrays and deconvolution

Stockslager

Ölçüm

Knudsen

et al. 2019

Review of Scientific Instruments

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Measuring the size of micron-scale particles plays a central role in the biological sciences and in a wide range of industrial processes. A variety of size parameters, such as particle diameter, volume, and mass, can be measured using electrical and optical techniques. Suspended microchannel resonators (SMRs) are microfluidic devices that directly measure particle mass by detecting a shift in resonance frequency as particles flow through a resonating microcantilever beam. While these devices offer high precision for sizing particles by mass, throughput is fundamentally limited by the small dimensions of the resonator and the limited bandwidth with which changes in resonance frequency can be tracked. Here, we introduce two complementary technical advancements that vastly increase the throughput of SMRs. First, we describe a deconvolution-based approach for extracting mass measurements from resonance frequency data, which allows an SMR to accurately measure a particle's mass approximately 16-fold faster than previously possible, increasing throughput from 120 particles/min to 2000 particles/min for our devices. Second, we describe the design and operation of new devices containing up to 16 SMRs connected fluidically in parallel and operated simultaneously on the same chip, increasing throughput to approximately 6800 particles/min without significantly degrading precision. Finally, we estimate that future systems designed to combine both of these techniques could increase throughput by nearly 200-fold compared to previously described SMR devices, with throughput potentially as high as 24 000 particles/min. We envision that increasing the throughput of SMRs will broaden the range of applications for which mass-based particle sizing can be employed.

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“…[12][13][14][15][16][17][18][19][20][21][22][23] Silica nanospheres were synthesized by the Stober method using the new apparatus aiming to improve the reproducibility in terms of the size distribution as well as the mean diameter. Flow FFF, another member of FFF family, has been tested for its applicability to size characterization of silica nanoparticles.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Size Characterization of Silica Nanospheres Using Sedimentation Field-Flow Fractionation (SdFFF)

Kim

Ahn²,

Kim³

et al. 2012

J. Nanosci. Nanotech.

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Silica nanoparticles were synthesized by a conventional emulsion polymerization by mixing ethanol, ammonium hydroxide, water and tetra ethyl orthosilicate (TEOS). A new reaction apparatus was assembled for a large scale synthesis of silica nanospheres in the laboratory, which was designed for uniform mixing of the reactants. The apparatus was equipped with a disc type agitator with six rectangular propellers. The new apparatus allowed high reproducibility in terms of the mean size and the size distribution of the silica nanoparticles with the relative standard deviation of less than about 6%. Sedimentation field-flow fractionation (SdFFF) was employed for determination of the size distribution of the silica nanoparticles. SdFFF provided size-based separation of the silica nanoparticles, with the retention time increasing with the size. When SdFFF analysis was repeated three times for the same sample, the standard deviation was less than 4%, showing reliability of SdFFF in size measurement. SdFFF seems to provide more accurate size distribution than DLS, particularly for those having broad and multimodal size distributions. Change in the agitation speed resulted in significant change in the mean diameter of the silica nanoparticles. Agitation speed of 400 rpm in 3 L reaction vessel yielded silica particles of about 100 nm in diameter, while at 200 rpm in 1 L vessel yielded those of about 500 nm.

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Measurement of the size and density of colloidal particles by combining sedimentation field-flow fractionation and quasi-elastic light scattering

Cited by 22 publications

References 8 publications

Measurement of the Density of Engineered Silver Nanoparticles Using Centrifugal FFF-TEM and Single Particle ICP-MS

Measurement of the Density of Engineered Silver Nanoparticles Using Centrifugal FFF-TEM and Single Particle ICP-MS

Rapid and high-precision sizing of single particles using parallel suspended microchannel resonator arrays and deconvolution

Synthesis and Size Characterization of Silica Nanospheres Using Sedimentation Field-Flow Fractionation (SdFFF)

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