Nano-Impacts: New Insights into Nanoparticles

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First the analytical need for nanoparticle detection will be introduced and electrochemical studies on suspensions of nanoparticles shown to allow the detection and characterisation of diverse nanoparticles at the single entity level. For electroactive nanoparticles such as those of silver, Ag, or iron oxide, Fe3O4, quantification of the charge associated with single collisional impacts, allows the sizing of the particles in the range from ca 100nm down to less than 5nm. The frequency of impact events permits particle concentrations to be estimated and the potential dependence indicates the chemical nature of the impact particles.

 

In many cases the electrochemistry reveals agglomeration or aggregation of the particles and since the monomers and agglomerated diffuse at different speeds the kinetics of de-agglomeration can be inferred in cases such as that of uncapped Bi2O3 particles where the electrochemical signals are dominated by the monomer signal whilst independent evidence shows significant agglomeration in bulk solution. Models for the extent of agglomeration have been developed.

 

Second the extension to the study, at the single entity, will be described in terms of the detection of bacteria, red blood cells, the doping of particles of solids and polymers and in nano-droplets will be reported.

 

Finally the possible nano-toxicity of silver will be discussed.

Salle E012 – 24 rue Lhomond - 75005 PARIS

Mardi 13 Juin 2017 10:30
Prof. COMPTON Richard
Oxford University
Séminaire du département
Unité de rattachement: 
UMR 8640
Equipe de rattachement 8640: 
Électrochimie