ORDERED ARRAYS OF METALLIC AND MAGNETIC NANOPARTICLES: LB PREPARATION AND PHYSICAL PROPERTIES

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ORDERED ARRAYS OF METALLIC AND MAGNETIC
NANOPARTICLESLB PREPARATION AND PHYSICAL
PROPERTIES

• J. Cirák1, J. Röschlová1, M. Weis1,
• A. atka2, M. Kopáni3, T. Hianik4, I. Capek5
• 1 Department of Physics, Slovak University of
  Technology, Faculty of Electrical Engineering and
  Information Technology, Bratislava.
• 2 International Laser Centre, Bratislava.
• 3 - School of Medicine, Bratislava.
• 4 - Department of Nuclear Physics and Biophysics,
  Faculty of Mathematics, Physics and Computer
  Sciences, Comenius University, Bratislava.
• 5 - Polymer Institute, Slovak Academy of
  Sciences, Bratislava.

Laboratory of Ordered Molecular Layers and Systems
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Introduction

• Subject of nanotechnology
• Controlled manufacturing and characterization
  of materials and systems with predetermined and
  artificially modified atomic and molecular
  structure. Nanoscience is actually Materials
  Science at atomic level.
• To accomplish that one needs to manipulate with
  atoms and molecules at nanoscale.
• The word nano relates to the dimension scale
  comparable with 1nm 10-9 m.
• Typical size of nanoobject ranges from 1 to 100
  nm.

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Approach
Nanostructure and device can be accomplished by
two approaches

• large object are modified to give smaller features

• small building blocks are produced and assembled
  into larger structures

R. Feynman There is plenty room at the bottom
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Organic molecules - advantages

• Size 1 100 nm, the scale that permits
  functional nanostructures
• Self assembly specific intermolecular
  interactions for the formation of spatial and
  temporal structures
• Molecular recognition extreme selectivity for
  the formation of intermolecular bonding
• Dynamical stereochemistry multiple distinct
  geometric structures or isomers with different
  properties
• Synthetic taylorability choice of composition
  and geometry which enables to vary molecules
  properties

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Properties of organic molecular systems

• physical properties can be purposefully modified
  by minor changes in the molecular structure
• various advantageous properties can be associated
  at the molecular level with possibility to form
  supramolecular ordered (organized) systems
• functionality of these systems is preserved on
  various length scales (molecules, nanoparticles,
  thin films, clusters, bulk)
• materials are biologically and environmentally
  compatible, recycling of products
• exploitation of the materials is not directly
  dependent on strategic raw materials

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Langmuir-Blodgett technique
enables to form highly ordered monomolecular
amphiphilic films at the air-water interface and
subsequently to transfer on a solid support

• Amphiphilic molecules consist of a
  hydrophilic(water soluble) and a
  hydrophopic(water insoluble) part.
• This amphiphilic nature of molecules is
  responsible for their association behaviour in
  solution and their accumulation at interfaces.

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Langmuir-Blodgett technique

• LB-films are compact multilayers of surfactant
  molecules produced by the Langmuir-Blodgett
  deposition technique onto solid surface.

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Materials

• Fatty acids
• Phospholipids
• Proteins
• Fullerene
• And many others

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Experimental study of physical properties of LB
films

• Nanoelectric phenomena in Langmuir monolayer
• LB deposition of alternating monomolecular layers
• LB surface modification for electrochemical
  sensors
• Polarised luminiscence from LB structures
• Organised LB systems of organometallic
  nanoparticles
• Interaction of molecules in biomembranes

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Metallic Nanoparticles

• Metallic nanoparticles include single metals,
  mainly transition metals, alloyed metals and
  metal oxide
• The applications of metallic nanoparticles are
  mainly
• high density magnetic data storage
• biomedical applications
• highly active catalyst
• nanotubes
• magnetic liquids

Dai et al (2002)
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LB-film preparation
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LB-film preparation
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Experimental Results

• Various techniques of surface analysis were used
  for measurement of physical and structural
  properties of planar array of magnetic
  nanoparticles
• MAXWELLS DISPLACEMENT CURRENTS
• TRANSMISSION ELECTRON MICROSCOPY
• SCANNING ELECTRON MICROSCOPY
• ELLIPSOMETRY

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MDC Measurement

• Observation of the dynamic response
• Change of a) order
• b) dipole moment
• c) number of molecules

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MDC Measurement

• Observation of the dynamic response
• Change of a) order
• b) dipole moment
• c) number of molecules

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Dipole Moment Measurement
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Dipole Moment Measurement
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Transmission Electron Microscopy
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Scanning Electron Microscopy
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Ellipsometry
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Voltammetry signal (electrochemical Coulomb
staircase) of iron oxide nanoparticles on the
a-SiH electrode. Individual changes in charge
states are indicated.
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Summary

• SEM as well as TEM confirmed highly monodisperse
  character of NPs
• Large-scale homogeneity and high quality
  multi-layer structure was observed for various
  deposition conditions by micrographs and
  ellipsometry measurement

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Cooperation

• Nanoelectric phenomena in Langmuir monolayer
• M. Iwamoto, Inst. of Physical Electronics, TIT
  Tokyo, Japan
• S. Nepurek, Inst. of Macromolecular Chemistry,
  ASCR, Prague
• LB layers of functionalized heterocyclic polymer
  layers
• G. Cík, Dept. of Environ. Sci., FChPT, STU
  Bratislava
• LB surface modification for electrochemical
  sensors
• K. Gmucová, V. Nádady, Inst. of Physics SAS,
  Bratislava

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Cooperation

• Polarised luminiscence from LB structures, OLEDs
  and FETs
• Bolognesi, Inst. of Macromolecular Chemistry,
  CNR,
• Milano, Italy
• J. Kovác, ILC, Bratislava
• R. Resel, Techn. Univ. of Graz, Austria
• Organised LB systems of metal and magnetic
  nanoparticles
• D. Petridis, Inst. of Materials Science,
  Demokritos, Athens, Greece
• A. atka, ILC, Bratislava
• E. Majková, Inst. of Physics, SAS Bratislava
• I. Capek, Inst. of Polymers, SAS Bratislava
• Biological membranes
• T. Hianik, P. Vitovic, Fac. of MPI, Comenius
  Univ., Bratislava
• P. Balgavý, D.Uhríková, Fac. of Pharmacy,
  Comenius Univ., Bratislava

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Thank you for attention.