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'Nano-impacts': An Electrochemical Technique for Nanoparticle Sizing in Optically Opaque Solutions.

Toh HS, Compton RG - ChemistryOpen (2015)

Bottom Line: Using the 'nano-impacts' method, silver nanoparticles were successfully detected and sized in the model opaque medium.The results obtained compared well with those using transmission electron microscopy (TEM), an ex situ method for nanoparticle size determination.The ability to use the 'nano-impacts' method in media unmeasurable to competitor techniques confers a significant advantage on the electrochemical approach.

View Article: PubMed Central - PubMed

Affiliation: Physical & Theoretical Chemistry Laboratory, Department of Chemistry, Oxford University South Parks Rd, Oxford, OX1 3QZ, UK.

ABSTRACT
Typical laser-dependent methods such as nanoparticle tracking analysis (NTA) and dynamic light scattering (DLS) are not able to detect nanoparticles in an optically opaque medium due to scattering or absorption of light. Here, the electrochemical technique of 'nano-impacts' was used to detect nanoparticles in solution in the presence of high levels of alumina particulates causing a milky white suspension. Using the 'nano-impacts' method, silver nanoparticles were successfully detected and sized in the model opaque medium. The results obtained compared well with those using transmission electron microscopy (TEM), an ex situ method for nanoparticle size determination. The ability to use the 'nano-impacts' method in media unmeasurable to competitor techniques confers a significant advantage on the electrochemical approach.

No MeSH data available.


5 % w/v alumina (0.05 μm) powder solution (left). Solution containing 100 pm of citrate-capped silver nanoparticle, sodium nitrate and alumina powder, used for anodic particle coulometry experiments (right).
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fig02: 5 % w/v alumina (0.05 μm) powder solution (left). Solution containing 100 pm of citrate-capped silver nanoparticle, sodium nitrate and alumina powder, used for anodic particle coulometry experiments (right).

Mentions: After determining the potential at which silver nanoparticles are oxidised in the opaque electrolyte, ‘nano-impact’ experiments were performed in the opaque solution. The opaque solution used for ‘nano-impact’ experiment is depicted in Figure 2 (sample on the right). The yellow silver nanoparticles present in the suspension causes it to appear as a yellow milky suspension. ‘Nano-impact’ experiments were performed by using chronoamperometry. Current-time transients of a fixed duration (50 s) were recorded at an overpotential of +0.6 V versus MSE. The results are summarised in Figure 3. In the absence of silver nanoparticles, no ‘spikes’ were observed; in presence of silver nanoparticles, current ‘spikes’ were observed. This indicates that alumina powder did not give any ‘spikes’, no ‘rogue’ nanoparticles were present, and the ‘spikes’ observed are solely attributed to the silver nanoparticles.


'Nano-impacts': An Electrochemical Technique for Nanoparticle Sizing in Optically Opaque Solutions.

Toh HS, Compton RG - ChemistryOpen (2015)

5 % w/v alumina (0.05 μm) powder solution (left). Solution containing 100 pm of citrate-capped silver nanoparticle, sodium nitrate and alumina powder, used for anodic particle coulometry experiments (right).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4522173&req=5

fig02: 5 % w/v alumina (0.05 μm) powder solution (left). Solution containing 100 pm of citrate-capped silver nanoparticle, sodium nitrate and alumina powder, used for anodic particle coulometry experiments (right).
Mentions: After determining the potential at which silver nanoparticles are oxidised in the opaque electrolyte, ‘nano-impact’ experiments were performed in the opaque solution. The opaque solution used for ‘nano-impact’ experiment is depicted in Figure 2 (sample on the right). The yellow silver nanoparticles present in the suspension causes it to appear as a yellow milky suspension. ‘Nano-impact’ experiments were performed by using chronoamperometry. Current-time transients of a fixed duration (50 s) were recorded at an overpotential of +0.6 V versus MSE. The results are summarised in Figure 3. In the absence of silver nanoparticles, no ‘spikes’ were observed; in presence of silver nanoparticles, current ‘spikes’ were observed. This indicates that alumina powder did not give any ‘spikes’, no ‘rogue’ nanoparticles were present, and the ‘spikes’ observed are solely attributed to the silver nanoparticles.

Bottom Line: Using the 'nano-impacts' method, silver nanoparticles were successfully detected and sized in the model opaque medium.The results obtained compared well with those using transmission electron microscopy (TEM), an ex situ method for nanoparticle size determination.The ability to use the 'nano-impacts' method in media unmeasurable to competitor techniques confers a significant advantage on the electrochemical approach.

View Article: PubMed Central - PubMed

Affiliation: Physical & Theoretical Chemistry Laboratory, Department of Chemistry, Oxford University South Parks Rd, Oxford, OX1 3QZ, UK.

ABSTRACT
Typical laser-dependent methods such as nanoparticle tracking analysis (NTA) and dynamic light scattering (DLS) are not able to detect nanoparticles in an optically opaque medium due to scattering or absorption of light. Here, the electrochemical technique of 'nano-impacts' was used to detect nanoparticles in solution in the presence of high levels of alumina particulates causing a milky white suspension. Using the 'nano-impacts' method, silver nanoparticles were successfully detected and sized in the model opaque medium. The results obtained compared well with those using transmission electron microscopy (TEM), an ex situ method for nanoparticle size determination. The ability to use the 'nano-impacts' method in media unmeasurable to competitor techniques confers a significant advantage on the electrochemical approach.

No MeSH data available.