Light Scattering Spectroscopy Lab Kiril A. Streletzky, Department of Physics

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Light Scattering Spectroscopy LabKiril A.
Streletzky,Department of Physics
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Light Scattering Spectroscopy Lab
Physics Department, CSU
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Light Scattering Spectroscopy
Fundamental Detectables Static Light Scattering
(SLS) average intensity I ? Mz, Rg,
B2 Dynamic Light Scattering (DLS) intensity
fluctuations dI(t)I(t)- I ? D, h, Rh,
spectrum DLS yields intensity-intensity
correlation function S(q,t)
Macromolecular solution in Thermal Equilibrium
and correlation time tc (Dq2)-1
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Systems studied by CSUs Light Scattering
Spectroscopy Lab

• Micelles, Surfactants
• Polymer Solutions
• Polymer Nanoparticles (Microgels)
• Zeolite and nano BN crystals
• Bio-Proteins (rotational diffusion)

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1) Micelles
Karen Johnson (BA in physics, 08) Exploring
Brij-35 micelles using DLS spectroscopy Summer -
Fall 07, Summer 08
K. Johnson, M. Lekan, and K.A. Streletzky,
manuscript to be submitted
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2) Polymer solutions Dynamics of Semirigid Rod
Polymers

• c?6g/l bi-modal spectra
• c?6g/l tri-modal spectra (!)
• Sharp Mode
• Broad Mode (Intermediate)
• ULTRASLOW Mode
• Confirmation of the reality of
  Solutionlike-Meltlike transition

G.D.J. Phillies and K. A. Streletzky, in Soft
Condensed Matter New Research, Dillon, K.. Ed.,
Nova Science NY, 2007 pp 219-263.
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2) Polymer solutions
R. McDonough, K.A. Streletzky, and P. Russo,
manuscript in preparation
Ryan McDonough (BS in
Physics 09) Study of Polymers Ultraslow Mode
with DLS and FRAP, Summer 07-Spring 09 (CSU,
LSU)
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2) Polymer solutions
Krista Freeman (BS in Physics, 2011) Determining
dn/dc of polymer solutions and studying their
structure by static light scattering Summer 08
Fall 08
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3) Microgels Structure and Dynamics below and
above the volume phase transition

• Estimates of Hydrodynamic radius
• (RH) for diffusive modes reveal
• modes 1 2 merge at 45C
• RH2 shrinks from about 500nm to 160nm
• RH1 increases from about 25nm to 150nm
• CONTIN results are noisier

K.A. Streletzky, J.T. McKenna, R. Mohieddine, J.
Polymer Science, B Polymer Physics, 46, 771
(2008)
Fast Heating 5C/step
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3) Microgels Effect of Heating Rate on Microgel
Volume Phase Transition
Slow Heating 0.5C/step
Slow Heating 0.5C/step
Fast Heating 5C/step
K.A. Streletzky and J.T. McKenna, J. Polymer
Science, B Polymer Physics, in press (2008)
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3) Microgels
Imaan Bermerzouga (BS in Biology Chemistry,
08) Study of differently synthesized
microgels Summer-Fall 07
K.A. Streletzky, I. Bermerzouga, and J.T.
McKenna, manuscript in preparation
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AFM image of HPC microgels in DI water at Troom
Synthesized microgels are they real?
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4) Zeolite and nano BN crystals

• monitoring zeolite crystallization and BN
  amorphization in clear solutions

L.Gora, K.Streletzky, R.W.Thompson,
G.D.J.Phillies, Zeolites 18, 119 (1997) A. N.
Streletskii, D. G. Permenov, B. B. Bokhonov, I.
V. Kolbanev, A. V. Leonov, I. V. Berestetskaya,
K. A. Streletzky, J. Alloys and Compounds,
accepted (2008).
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5) Bio-proteins

• Maxwell Orseno (BS in Physics, 2010)
• Building and tuning up a new DLS set-up for
  polarized and depolarized light scattering.
• Summer 08 Spring 09

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Spring/Summer 09 Employment/ Independent Study
Opportunities

• Undergraduate/Graduate Research Projects for the
  Spring/Summer09
• Bio-physics Research Assistant. A position for a
  Physics/Chemistry Major to study loading
  capabilities and potential pharmaceutical
  applications of polymer microgel nanoparticles.
• Physics Research Assistant. A position to expand
  the studies of structure, dynamics, and phase
  transition of polymeric nanoparticles using
  dynamic and static light scattering
  spectroscopies.
• Light Scattering Laboratory Assistant. A position
  to assist in our ongoing experimental studies of
  complex fluids (polymer solutions, bioproteins,
  micelles) or nanocrystals (zeolites, nano BN)
• Optics Laboratory Assistant. A position to assist
  in designing, optimizing testing an advanced
  optics set up for the Advanced Optics Laboratoy
  (Fourier Transform Infra-Red (FTIR),
  Spectrometry and X-ray diffractometry).