Abdulrahman Khalaf Ali

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  • IName: Abdulrahman Khalaf Ali

    Thesis Title: (Preparation of Ag and Au Nanoparticles by Pulsed Laser

    Ablation in Liquids)

    Supervisor: Ass. Prof. Dr. Dayah N. Raouf

    Date: 2010

    No. of Pages: 114

    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 g/pulse, and it was increased about

    21 times.

  • II

    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, =532nm; the average particle size dropped from

    14 to 8nm.

    Novel bimetallic of AuAg 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 =532nm and E=900

    mJ.

    Keyword: Pulsed, Nanoparticles, Ag, Au, liquid, Nd: YAG

  • Preparation of Ag and AuNanoparticles by Pulsed Laser Ablation

    Abdulrahman Khalaf Ali

    Submitted to the Department of Applied Sciences at the University of

    as a Partial Fulfilment of the

    Doctor of Philosophy in Laser Physics

    Assistant

    I

    Preparation of Ag and AuNanoparticles by Pulsed Laser Ablation

    in Liquids

    By

    Abdulrahman Khalaf Ali

    A Thesis

    Submitted to the Department of Applied Sciences at the University ofTechnology

    ulfilment of the Requirement for the Degree

    Doctor of Philosophy in Laser Physics

    Supervised by

    istant Prof. Dr.Dayah N. Raouf

    Baghdad (2010)

    Preparation of Ag and AuNanoparticles by Pulsed Laser Ablation

    Submitted to the Department of Applied Sciences at the University of

    egree of

  • II

    ( - )

  • III

    Supervisor Certification

    I certify that this thesis entitled: (Preparation of Ag and Au

    Nanoparticles by Pulsed Laser Ablation in Liquids) was prepared under my

    supervision at the University of Technology, department of applied sciences, in

    partial fulfilment of the requirements for the degree of Doctor of Philosophy in

    Laser Physics.

    Signature:

    Name: Dr. Dayah N. Raouf

    Title: Assistant Professor

    Date: / / 2010

  • IV

    Linguistic Certification

    I certify that this thesis entitled: (Preparation of Ag and Au Nanoparticles

    by Pulsed Laser Ablation in Liquids) was prepared under my linguistic

    supervision. It was amended to meet the style of the English language.

    Signature:

    Name: Dr. Mohamed Saleh Ahmed

    Title: Assistant Professor

    Date: / / 2010

  • VExamination Committee Certificate

    We certify that we have read this thesis entitled (Preparation of Ag and AuNanoparticles by Pulsed Laser Ablation in Liquids) and as an examiningcommittee examined the student '' Abdulrahman Khalaf Ali'' in its contentsand that in our opinion; it meets the requirements of awarding the degree ofDoctor of Philosophy of Science in Laser Physics.

    Signature: Signature:Name: Dr. Bassam G. Rasheed Name: Dr. Khawla Salah KhashanTitle: Assistant Professor Title: Assistant Professor

    (Member) (Member)Date: / / 2010 Date: / / 2010

    Signature: Signature:Name: Dr. Adawiya J. Haider Name: Dr. Nadir Fadhil HabbubiTitle: Professor Title: Professor

    (Member) (Member)Date: / / 2010 Date: / / 2010

    Signature: Signature:Name: Dr. Dayah N. Raouf Name: Dr. Mazin M. EliasTitle: Assistant Professor Title: Professor

    (Supervisor) (Chairman)Date: / / 2010 Date: / / 2010

    Approved by the School of Applied Sciences, University of Technology.

    Signature:Name: Kassim S. KassimTitle: Head of School of Applied SciencesDate: / / 2010

  • VI

    Acknowledgment

    After thanks my glorious ALLAH, I am pleased to acknowledge theassistance and support for many people whom had support me in completion of

    this work.

    First I would like to thank my supervisor Dr. Dayah N. Raouf for skilful

    scientific guidance, who always supported my research effort, during the long

    period time of this project.

    I would like to present my spatial thanks and great gratitude to Dr. Bassam

    G. Rashid, the head of laser branch, for his unlimited support for the

    experimental requirements.

    Also, I would like to express my deep appreciation and respect to all the

    department of applied science staff, especially of laser branch.

    I am indebted to the electronic microscope centre-collage of medicine/ Al-

    Nahrain University for their helpful in TEM measurements. I am also grateful to

    the chemical Lab.-collage of science/ Baghdad University for unlimited

    assistant in AAS measurements.

    Abdulrahman15-1-2010

  • VII

    Dedication

    I would like to dedicate my Doctoral Thesis to my family: parent, wife,brothers and sisters.

  • VIII

    AbstractThis 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 ahigh ablation rate and size-selected manner with a high concentration, long periodof 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 goldmetal plates immersed in double distilled and deionised water DDDW or otheraqueous 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 bestformation 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 8and 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 thesurface 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; howeverit was estimated to be about 8.66 g/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 sizeof 14 nm, respectively. All the size measurements have been confirmed by TEM.

    There is a simultaneous possibility of on-line observation of the nanoparticlesformation via measuring the variation in nanoparticles absorption at the peaks ofSPE using 532nm, 1mW diode laser.

    The optimum concentration for the formation of Ag nanoparticles in varioussolutions were: NaCl (2.5 mM), SDS (25 mM) and PVP (5 mM) which optimizethe formation efficiency, reduces the size and size distribution, enhance dispersityand prevents aggregation of the prepared nanoparticles.

    Resizing and reshaping of Ag and Au nanoparticles have been performed usingpulsed Nd-YAG laser, =532nm; the average particle size dropped from 14 to 8nm.

    Novel bimetallic of AuAg core-shell nanoalloys were synthesized. Thenanoalloys appear to be nearly spherical with average size of 19 nm. Theirradiation process has been done by Nd-YAG laser, with =532nm and E=900 mJ.

  • IX

    List of AbbreviationsAAS Atomic Absorption Spectroscopy

    AD After Date

    AgNPs Silver Nanoparticles

    Au-Ag Bimetallic of GoldSilver Nanoalloys

    AuNPs Gold Nanoparticles

    BC Before Christ

    DDDW Double Distilled and Deionised Water

    e.g. for example (exempli gratia)

    et