Transcript ART OF COMPLAINING

DYNAMIC LIGHT
SCATTERING
Particle Size Analysis
Group 2
KIM DONGMIN
CHAE JONGMIN
SONG SI NAE
IM SUNHA
YOON JIHWAN
THEORY
Theory
 Brownian Motion
 Hydrodynamic Diameter
 Rayleigh Scattering
 Mie Theory
 Doppler Effect
Theory
 Brownian Motion
Brownian motion is the random movement of
particles due to the DLS is concerned with
measurement of particles suspended within a liquid.
The larger the particle, the slower the Brownian
motion will be…
Theory
 Brownian Motion
Theory
 Hydrodynamic Diameter
The diameter that is measured in Dynamic Light
Scattering is called the hydrodynamic diameter and
refers to how a particles diffuses within a fluid.
Factors that affect the diffusion speed of particles
1. Ionic Strength of Medium
2. Surface Structure
3. Non-Spherical Particles
Theory
 Hydrodynamic Diameter
Ionic Strength Of Medium
kT
d(H) =
3πηD
d(H) = hydrodynamic diameter
D = translational diffusion coefficient
k = Boltzmann’s constant
T = absolute temperature
η = viscosity
Theory
 Hydrodynamic Diameter
Surface Structure
: Any change to the surface of a particle that
affects the diffusion speed will
correspondingly change the apparent size of
the particle
Non-Spherical Particle
: Diameter of a sphere that has the same
transational diffusion speed as the particle
Theory
 Rayleigh Scattering
Rayleigh scattering (named after Lord Rayleigh) is the
elastic scattering of light or other electromagnetic
radiation by particles much smaller than the
wavelength of the light.
Main reason why the sky is blue.
Theory
 Mie Theory
When the size of the particles becomes roughly
equivalent to the wavelength of the illuminating light,
then a complex function of maxima and minima with
respect to angle is observed.
Theory
 Doppler Effect
Theory
 Doppler Effect
The change in frequency and wavelength of a wave
for an observer moving relative to the source of the
waves.
It is commonly heard when a vehicle sounding a siren
approaches, passes and recedes from an observer.
DYNAMIC LIGHT
SCATTERING
Dynamic Light Scattering
1. The speed at which the particles are diffusing due
to Brownian motion is measured.
2. This is done by measuring the rate at which the
intensity of the scattered light fluctuates when
detected using a suitable optical arrangement.
Dynamic Light Scattering
Sample Cell
Incident Beam
LASER
Screen
Speckle
Pattern
Dynamic Light Scattering
Dynamic Light Scattering
Large Particle
Intensity
Intensity
Small Particle
Time
Time
Dynamic Light Scattering
L
A
S
E
R
Attenuator
Nano S
Nano ZS
Nano S90
Nano ZS90
173º
173º
90º
90º
Detector
Cell
90º
Digital Signal
Processor
LET’S DO IT
Particle Size Measurement
Particle Size Measurement
Particle Size Measurement
1. Go to the system menu of apparatus and click on
“Size Measurement”
2. Change the angle on the apparatus to 60º
by turning the knob.
Particle Size Measurement
3. Now enter the value of angle 90º in the system menu.
Particle Size Measurement
4. Select the appropriate solvent from the solvent list
in system menu. If the sample contains water as
solvent, then check the water in solvent category.
Particle Size Measurement
5. Now fill the sample in the DLS cell, for inorganic
solvents use plastic cell and dispose it after use. For
organic solvents use Quartz glass cell.
Particle Size Measurement
6. Check the intensity on the intensity monitor, it
should be between 8000~14000 and its color should
be blue.
Particle Size Measurement
7. Now press the “GO” button on the toolbar.
Particle Size Measurement
8. A small window will appear on the monitor, enter
the filename, grouping, and comments.
9. Then press the “Save Auto” button, the equipment
will start analyzing the sample.
Particle Size Analysis
1. Go to the system menu and select “Size Analysis”.
2. Click on the DLS button in the toolbar.
3. Select the grouping where the size measurement
file was saved and open the required file.
4. Then click on the “Re-Analysis” button.
Particle Size Analysis
5. It will show the analysis of the selected file, now if
you want to edit more options, click on the preview
button in toolbar. Then you can add more options to
the analysis
ANY QUESTIONS?