Abedul-Samad Jawabreh An najah National Univresity Directed by Dr.Issam Rasheed. Production of Nanoparticles by laser. overview.
Nanotechnology is beginning to allow scientists, engineers, and physicians to work at the cellular and molecular levels to produce major advances in the life of sciences and healthcare.
Nanostructures and nanoparticles differ in their chemical ,Optical, magnetic and electric properties from the bulk material of which they are made, and hence enable new application possibilities.
the excellent properties of these materials when compared with their bulk counterparts provide a very promising future for their use in many fields
The challenge does not focus on the synthesis of nanoparticles but rather on the integration of these nanoparticles into materialIntroduction
The first one who discribe the nano scale is Richard Feynman (he has the Nobel )
Was invented by the two science Gerd Binnig & Heinrich Rohrer
1986 – “Engines of Creation” - First book on nanotechnology by K. Eric Drexler.
gold nano particles
Nano = 10-9 m
Materials with dimensions and range of 100 nm to 0.1 nm
You can put 10^7 H atom side by side in 1 mm
One nanometer spans 3-5 atoms lined up in a row
Human hair is five orders of magnitude larger than nanomaterials
1.27 × 107 m
0.7 × 10-9 m
1 billion times smaller
10 millions times smaller
1 nanometer (nm)
الأبعاد في المقياس
Virus: 10-100 nm.
Hemoglobin: 7 nm.
Water (H2O): 0.2 nm
~ 60-100 m
كريات دم حمراء
مع كرية بيضاء
~2.5 nm width
ذرات ومسافات سيليكون
~tenths of nm
Color: The colour of a material is determined by the wavelength of light photons absorbed by it. So, the clusters of different sizes will have different energy level separations hence different colours and the size of the cluster can be used to estimate the colour of the material.
Geometric Structure: The geometric structure of large nanoparticles depends on size.
Basic structure: the nanoparticles Metal
exist as a group of metal atoms forming
The application of laser ablation is called pulsed laser deposition (PLD).
laser ablation was mainly used for the analysis of various materials and further development of PLD was slow. After the discovery of high-temperature superconductivity in 1986, the research interest in PLD increased dramatically. The first successful deposition of a YBCO film was made in 1987. The principle of laser ablation is illustrated in Fig. 1.Laser Ablation and Thin-Film Deposition (PLD)
exploit high-power laser pulses, e.g., from an excimer or a Nd:YAG laser.
The interaction between laser pulses and the target depends strongly on the intensity of the incoming laser beam.
There are many different mechanisms through which energy can be transferred to the target and the most important ones is
collisional sputtering,Laser-Target Interaction
The mechanism is of great importance if the incoming beam consists of massive particles, such as ions. In the case of photons, the maximum transfer of energy (E2) is negligible as one can see from the following equation :-
E1: the energy of the incoming particles
M1: the mass of the incoming particles
M2: the mass of the target particles
The process of PLD can generally be divided into four stages:
There is an increasing interest in the production andcharacterization ofnanoparticles of different elementsand compounds due to their importance in fundamentalresearch as well as in technological applications [Different techniques for the production ofnanoparticles have been developed, such as electrochemical deposition, ballmilling, sputtering and laser ablation.
In the method ofproduction of nanoparticlesby laser ablation,nanoparticles are produced around the ablated area oron a suitably chosen substrate either as isolated entitiesor as a continuous deposit (agglomeration ofnanoparticles), by pulsed laser deposition ablation of asolid target in ambient air, vacuum or in a controlledatmosphere of some gas. Alternatively, acolloidal solution of nanoparticles is produced byablating the target while it is immersed in a liquidsolution which may also contain a suitable surfactantto prevent agglomeration of the nanoparticles and increase the stability of the solutionNANO-PARTICLE GENERATION BY FEMTO SECOND LASER ABLATION
Femtosecond laser ablation as a method for theproduction of nanoparticles offers mainlymany advantages :-
the ejected particles do not
interact with the laser beam
2. the mechanism of formation
of nanoparticles is different
as compared to the case of
ablation with long pulses .
2- medicin and drugs
3- bio enginearing
4- optical enginearing
5- nano devices
6- energyApplications of Nanotechnology
 Wikipedia, There's Plenty of Room at the Bottom, <http://en.wikipedia.org/wiki/Plenty_of_Room_at_the_Bottom>
Richard Feynman, There's Plenty of Room at the Bottom, Zyvex, <http://www.zyvex.com/nanotech/feynman.html>
Chris Toumey, Apostolic Succession, <http://pr.caltech.edu/periodicals/EandS/articles/LXVIII1_2/Feynman.pdf>
. Hirai, H ,Toshima, N. Tailored Metal Catalysts; Iwasawa, Y., Ed.; D. Reidel: Dordrecht, pp 87-140, (1986).References
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