Abstract:Various techniques are used to measure the mean particle size (PS) and the particle size distribution (PSD) and relevant uncertainties of the measured mean PS and PSD can be obtained by using statistical treatments. Among those techniques, microscopic analysis methods provide the possibility to observe individual particles, allowing detailed information about the PS. However, there is no existing method to estimate the uncertainty of the PSD from a finite number of data obtained by microscopic measurement. We … Show more
“…Considering that the properties of nanoparticles of varying sizes differ (in fact, the smaller the size, the more significant the difference), it is important to take into account not only the average size of nanoparticles but also the distribution of particles according to size. For example, two sols with the same average size but different degrees of dispersion will exhibit different toxicity in biological structures due to the presence of small particles in polydisperse sol that are able to penetrate cell membranes quite easily [7]. Therefore, in general, degree of dispersity should be taken into account interpreting the processes involving polydisperse system participation.…”
The paper proposes a mathematical model describing electrooxidation of a polydisperse system of metal nanoparticles from the surface of an indifferent macroelectrode. It is shown that the degree of dispersion of a nanoparticle ensemble affects the shape of oxidation voltammograms. When the degree of dispersion rises and the average size of nanoparticles becomes smaller, the range of oxidation potentials increases. The results of the experimental study of electrooxidation of gold nanoparticles with different degrees of dispersion are given. The particles were localized on the surface of graphite screen-printed electrodes. A good agreement between the parameters of the experimental and calculated voltammograms confirms the correctness of the proposed model.
“…Considering that the properties of nanoparticles of varying sizes differ (in fact, the smaller the size, the more significant the difference), it is important to take into account not only the average size of nanoparticles but also the distribution of particles according to size. For example, two sols with the same average size but different degrees of dispersion will exhibit different toxicity in biological structures due to the presence of small particles in polydisperse sol that are able to penetrate cell membranes quite easily [7]. Therefore, in general, degree of dispersity should be taken into account interpreting the processes involving polydisperse system participation.…”
The paper proposes a mathematical model describing electrooxidation of a polydisperse system of metal nanoparticles from the surface of an indifferent macroelectrode. It is shown that the degree of dispersion of a nanoparticle ensemble affects the shape of oxidation voltammograms. When the degree of dispersion rises and the average size of nanoparticles becomes smaller, the range of oxidation potentials increases. The results of the experimental study of electrooxidation of gold nanoparticles with different degrees of dispersion are given. The particles were localized on the surface of graphite screen-printed electrodes. A good agreement between the parameters of the experimental and calculated voltammograms confirms the correctness of the proposed model.
“…Indeed, the edge of the nanoparticles merges often with the noise. The threshold must be carefully fixed because it straight 06007-p. 4 impacts the calculation of the NP lateral diameter in the case of SEM measurements.…”
“…Finally the final size distribution histogram is shown to the user, with the mean value and the standard deviation. The user has the choice to fit the histogram with a normal or a lognormal distribution [4].…”
Abstract. Using combined AFM (Atomic Force Microscope) and a SEM (Scanning Electron Microscope) makes it possible to accurately measure a nano-object in 3 dimensions. This paper deals with the traceable measurements of the size and the size distribution of a SiO2 sphericalshaped nanoparticle population performed by both microscopy techniques. The complementary nature of AFM and SEM is investigated. The construction of size distribution histogram was carried out by means of a homemade program described here. This semi-automatic program is capable of counting only isolated nanoparticles and eliminating measurement artefacts and aggregates. Finally, a comparison between both measurement types is proposed.
“…Grâce à cette technique, il est aisé d'atteindre les 100 nanoparticules nécessaires afin que la distribution en taille déterminée soit représentative de l'ensemble de la population [25] de la solution colloïdale de départ. Ce traitement sera par la suite adapté aux images SEM afin de mieux étudier la complémentarité AFM/SEM.…”
Section: Comptage Des Nanoparticules Et Détermination Des Hauteursunclassified
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