| Autor: |
Safronov, A., Leiman, D., Blagodetelev, D., Kotov, Yu., Bagazeev, A., Murzakaev, A. |
| Zdroj: |
Nanotechnologies in Russia; Dec2010, Vol. 5 Issue 11/12, p777-785, 9p |
| Abstrakt: |
The aggregation of air-dry AlO nanopowders prepared by electrical wire explosion (EWE) and plasma deposition in a gas atmosphere was studied by dynamic laser light scattering during redispersion in water. The specific surface of nanopowders was from 9 to 38 m/g. It was shown that aqueous suspensions of nanopowders stabilized by a double electric layer with an electrokinetic ξ-potential magnitude of 30-40 mV contain coexisting individual particles and their primary aggregates (35-50 wt %). The average size of the primary aggregate is approximately three times larger than the average size of an individual particle. The former probably consists of a central particle surrounded by the first coordination sphere. As the medium pH varies from 2.5 to 11.5, the electrokinetic potential of the AlO nanoparticle suspension monotonically decreases from +40 to −40 mV. Near the isoelectric point (IEP), aggregation is significantly enhanced, which results in the formation of larger secondary aggregates of 10-10 individual particles. The use of Na citrate as an electrostatic stabilizer prevents the formation such large aggregates, and only an increase in the fraction of primary aggregates and a decrease in the number of individual particles occur near the IEP. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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