Preparation of Ag and au nanoparticles by pulsed laser ablation in liquids
Dissertant
Thesis advisor
University
University of Technology
Faculty
-
Department
Applied Sciences Department
University Country
Iraq
Degree
Ph.D.
Degree Date
2010
English Abstract
This thesis has presented an alternative-novel, easy, fast and one-step method for the preparation of pure and stable noble metal versatile nanoparticles NPs in a high ablation rate and size-selected manner with a high concentration, long period of stability, less aggregation, non toxic and contamination.
Noble metals silver and gold NPs were synthesized by pulsed (Q-switched, 1064 or 532nm doubled frequency-Nd: YAG) laser ablation of silver and gold metal plates immersed in double distilled and deionised water DDDW or other aqueous solutions such as: NaCl, sodium dodecyl sulphate SDS, polyvinylpyrrolidone PVP, Ethanol and Acetone, each with various concentrations.
The optimum preparation parameters had been optimized for the best formation efficiency of pulsed laser ablation in liquids (PLAL) process, which are: laser shots is 15 and 10 pulses, laser energy is 600 and 500 mJ, liquid depth is 8 and 7 mm, laser fluence is 47.4 and 105.8 J/cm2 for silver and gold, respectively.
Moreover, the optimum ablation laser wavelength was 1064 nm.
The formation efficiency of PLAL process was quantified in term of the surface plasmon extinction SPE peaks and it was enhanced greater than 220 times, as well as the concentration of ablated Ag NPs which obtained via AAS; however it was estimated to be about 8.66 μg/pulse, and it was increased about 21 times.
The SPE spectra shows a sharp and single peaks around 400 or 526 nm, indicating the production of pure and spherical Ag and Au NPs with average size of 14 nm, respectively.
All the size measurements have been confirmed by TEM.
There is a simultaneous possibility of on-line observation of the nanoparticles formation via measuring the variation in nanoparticles absorption at the peaks of SPE using 532nm, 1mW diode laser.
The optimum concentration for the formation of Ag nanoparticles in various solutions were: NaCl (2.5 mM), SDS (25 mM) and PVP (5 mM) which optimize the formation efficiency, reduces the size and size distribution, enhance dispersity and prevents aggregation of the prepared nanoparticles.
Resizing and reshaping of Ag and Au nanoparticles have been performed using pulsed Nd-YAG laser, λ=532nm; the average particle size dropped from 14 to 8nm.
Novel bimetallic of Au–Ag core-shell nanoalloys were synthesized.
The nanoalloys appear to be nearly spherical with average size of 19 nm.
The irradiation process has been done by Nd-YAG laser, with λ=532nm and E=900 mJ.
Main Subjects
American Psychological Association (APA)
Ali, Abd al-Rahman Khalaf. (2010). Preparation of Ag and au nanoparticles by pulsed laser ablation in liquids. (Doctoral dissertations Theses and Dissertations Master). University of Technology, Iraq
https://search.emarefa.net/detail/BIM-305306
Modern Language Association (MLA)
Ali, Abd al-Rahman Khalaf. Preparation of Ag and au nanoparticles by pulsed laser ablation in liquids. (Doctoral dissertations Theses and Dissertations Master). University of Technology. (2010).
https://search.emarefa.net/detail/BIM-305306
American Medical Association (AMA)
Ali, Abd al-Rahman Khalaf. (2010). Preparation of Ag and au nanoparticles by pulsed laser ablation in liquids. (Doctoral dissertations Theses and Dissertations Master). University of Technology, Iraq
https://search.emarefa.net/detail/BIM-305306
Language
English
Data Type
Arab Theses
Record ID
BIM-305306
