van Phu D.,Vietnam Atomic Energy Commission |
Lang V.T.K.,Vietnam Atomic Energy Commission |
Lan N.T.K.,Vietnam Atomic Energy Commission |
Duy N.N.,Vietnam Atomic Energy Commission |
And 4 more authors.
Journal of Experimental Nanoscience | Year: 2010
Radiation-induced synthesis of colloidal silver nanoparticles (Ag-NPs) using chitosan (CTS) as a stabiliser and free radical scavenger is feasible and satisfiable to green method. The conversion dose (Ag+ into Ag0) was determined by UV-Vis spectroscopy and Ag-NPs size was characterised by transmission electron microscopy. The average diameter of Ag-NPs was smaller than 10nm with narrow size distribution and the colloidal Ag-NPs have good stability for a long time of storage. The effect of several parameters, such as pH, Ag+ and CTS concentration and molecular weight of CTS on Ag-NPs size was also investigated. Ag-NPs of 7nm exhibited highly antimicrobial effect. The inhibitory efficiency of Ag-NPs for Staphylococcus aureus was more than 99.9% at 5 ppm and the effective dose (ED50) of inhibition for Corticium salmonicolor was of 27.2ppm. © 2010 Taylor & Francis.
Quoc An H.T.,Institute of Applied Material Science |
Pham Huu T.,Institute of Applied Material Science |
Le Van T.,Institute of Applied Material Science |
Cormier J.M.,GREMI |
Catalysis Today | Year: 2011
The combination of heterogeneous catalysts with non-thermal plasma (DBD operated in sinusoidal mode) was investigated for the removal of toluene from air at room temperature. The DBD reactor gives the possibility to introduce the heterogeneous catalyst directly into the discharge zone (in-plasma catalysis, IPC) or to place the catalyst downstream the plasma zone (post-plasma catalysis, PPC). Various catalytic materials based on Ag, Au, Cu, Co, Mn, La, and Nb, supported on Al 2O 3 and CeO 2 in powder form has been tested to select the catalysts that present the highest activity in the presence of plasma. Without plasma, the reaction of toluene conversion over perovskite, Al 2O 3, and OMS-2 based catalysts are promoted at high temperature (200-400 °C). In the absence of catalysts, the toluene removal efficiencies were in the 55-60% range. When the plasma was combined to catalyst, the toluene removal efficiency strongly increased when the catalysts are in IPC position. Best results, up to 96% toluene conversion, were obtained when using 1 wt% Au/Al 2O 3 and Nb 2O 5 catalysts. © 2010 Elsevier B.V.
Tue Anh N.,Vietnam Atomic Energy Institute |
Van Phu D.,Vietnam Atomic Energy Institute |
Ngoc Duy N.,Vietnam Atomic Energy Institute |
Duy Du B.,Institute of Applied Material Science |
Quoc Hien N.,Vietnam Atomic Energy Institute
Radiation Physics and Chemistry | Year: 2010
Gold nanoparticles with pre-selected size in the range 5-40 nm were synthesized by γ-irradiation of Au3+ solution containing natural polysaccharide alginate as a stabilizer. The gold nanoparticles with controllable size were prepared by two approaches: (i) varying the concentration of Au3+ from 0.25 to 1 mM and alginate from 0.25% to 1% (w/v) and (ii) enlargement of seed particles with double size from 20 to 40 nm at [Au3+]/[Au0]=6. The obtained gold nanoparticles were characterized by UV-vis spectroscopy and transmission electron microscopy. The results indicated that γ-irradiation method is suitable for production of gold nanoparticles with controllable size and high purity. © 2009 Elsevier Ltd. All rights reserved.