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PIC Workshop: NIST Capabilities and
Proposed Research:
Optical Scattering and
Morphological Measurements
(surface and subsurface)
Measurement Capabilities and Recent Accomplishment
Future Plan
Other accessible measurement capabilities at NIST
Optical and Morphological
Measurement Capabilities
At Polymeric Materials Group, BFRL, NIST
Laser Scanning Confocal Microscope (LSCM)
Atomic Force Microscope (AFM)
Optical Scattering Instrument (OSI)
Laser Scanning Confocal Microscopy (LSCM)
Topography & Microstructure
3D topographic data
wp
Z-Scan 12
hp
Df
8
4
0
° Non-destructive
° High resolution Onset
° Optical slices 2D projection
° Depth profiling
Optical Scattering Facility at BFRL
Fully automated; five-axis goniometric sample stage
Two-dimensional detector with a wide range of
dynamic range
In-plane/out-of-plane scattering
Reflection/forward scattering
ASTM wavelength range for color and gloss
measurements
A308/226
Sample Stage
Detector
Light Sources
(lasers,white light)
Illumination of Optical Scattering Instrument (OSI)
• Laser 632 nm
• Scanning Wavelength Illumination (SWI) System
- DC Xenon Arc, ozone free, 150 Watt
- 320 nm to 800 nm minimum scan, automated
- Compatible with CIE colorimetry specifications
Monochromator- Every 5 nm
16
14
480 nm
530 nm
12
630 nm
w h ite lig h t
10
Intensity (counts)
8
6
4
2
0
300 400 500 600 700 800
W a v e le n g th (n m )
Optical Scattering BRDF Measurement
(Reflectance)
2D 2D-scattering profile In-plane &
Detector
Laser
3o Out-of- the-plane
white light
Scattered Intensity
Sample
Light
θi Measuring entire
θs scattering space
θas
2D-Detector
θi : angle of incidence (0o - 60o)
θs = θi : Specular angle
θas = Aspecluar angle
Other Measurement
Capabilities and Recourses at Polymeric Group
Integrating Sphere-based UV Chamber (SPHERE)
and Automatic Analytic Lab (AAL)
Custom Designed Multi-Angle Light
Scattering Instrument
• Static (angle resolved)
time-averaged
• Dynamic (time resolved)
time-dependent
• Multi-angle, wavelength
1000
5o to 175o, 400 nm - 800nm
868 nm
500 nm
• Adjustable temperature
Scattered Intensity
100 300 nm
57 nm 10o to 100o C
90 nm
10
• Diffusive scattering
high concentrations
1 • Different polarized states
0.01
-1
high aspect shape
Scattering Wavevector q (nm )
Measurable Size Range:
5 nm – 10 μm (static),1 nm – 5μm (dynamic)
Chemical Nanoprobe Microscopy (CFM)
Functionalized atomic force microscopy (f-AFM)
a. Chemically Functionalized Tips
x : -CH3 -COOH -OH SAM
b. Attach carbon nanotube (CNT)
modification: oxidation – plasma treatment
c. Environmental chamber
control humidity, temperatures
Nanopore Measurement
Conventional Si Probe Example with MWCNT Probe
Subsurface imaging on SWNTs by EFM
Height Phase Height Phase
Cross section analysis: the
3D AFM image EFM width of the pitch is ~337nm.
EFM
Top of the pitch is not very flat.
Before PMMA coating After 100nm PMMA coating
Recent Accomplishments
Surface Roughness and Optical Properties
of a Clear Coating – Completed 2000
Characterize Surface Roughness Measure & Model reflectance
Rough
smooth
200 nm rms 800 nm rms
Computer-based Gloss Standards for Rendering
Rendered Image
Gloss, D523
Haze (distinctness of image), D4039
Optical Scattering from Metallic Coatings
Completed 2002
Virtual Comparison
LSCM Data
Digital Camera Image Rendered Image
C F
C F
Ray Scattering
Model
Measured & Calculated BRDF Beard Maxwell Model
Used BMM to describe surface and subsurface scatter
Develop a Methodology for Measuring and further Predicting
Appearance of a Weathered Coating – Ongoing Research
Feed data to computer rendering program and predict weathered data
• Demonstrated the ability to quantify optical properties and relate to physical
properties of a coatings.
• Established a feasible technical approach for measuring and further
predicting appearance of a weathered coating
Scratch Damages and Optical Scattering Profiles
Specular
scattering
Off-specular
scattering
Different scratch damage patterns → different scattering profiles
A methodology to link optical scattering property to scratch damage
– measurement protocols for quantitative characterization of a scratch -
A Methodology to Link Optical Scattering Property
to Scratch Damage
– measurement protocols for quantitative characterization of a scratch
Optical modeling Impact on
Optical Visibility of a Scratch
Properties
Material
Scratch
&
Morphology
Mechanical
Scratch modeling Properties
(mechanical response)
Scratch Test
Method
Key parameters: scratch profile (width, depth, aspect ratio, pattern),
index of refraction, surface roughness, subsurface microstructure,
incident and scattering angles
Severity of scratch damages invisible
Clear coat
Black PMMA
Black PMMA with fillers
Specular: no distinguish difference
Off- Specular: scratch damage ⇓ ⇔ intensity ⇓
Proposed Future
Optical Scattering Research
• Develop optical metrology for better understanding the optical
properties of materials and protocol for actual measurements
Including metallic coatings, special color effect coatings
• Investigate the effect of microstructure, optical properties, and other
coating properties on scratch behavior and visibility.
• Develop real-time optical scattering measurement in combination of
surface morphologic, mechanical and chemical measurements.
• Expend comparison between optical scattering metrology and other
existing optical measurements for scratch appearance (gloss, color,
haze, …)
Find a better way to evaluate the scratch resistance
Provide a better measurement protocol
Other Available Measurement
Capabilities and Recourses
Physics Lab
- Standard Color Colorimetric Measurements
- Color Rendering Visual Science
NIST Center for Neutron Research (NCNR)
- SANS and USANS, Backscattering
IT and MSEL (Center for Theoretical and Computational Materials Science)
- Computation, modeling, 3D Reconfigurable Automatic Virtual Environment
Scattering Metrology – Light, Neutron, and X-ray scattering
1 nm-10 μm
USANS
SANS
SLS
Structural Properties
DLS
Autocorrelation Function
Small cluster
Large cluster
Static and Dynamic
Cluster Size & Shape
Cluster-Cluster Interactions 1
Morphology
Spatial Distribution
Time (s)
Particle methods for simulation of subsurface multiphase fluid flow
(MD, DPD and SPH)
• Simulate complex processes such as fluid-fluid-solid contact line dynamics
• and mesoscale processes in which thermal fluctuations play an important role
(polymers, colloids, biofilm)
Liquid propane in
Dispersion in fractured porous medium
Nitrogen
(SPH simulation)
(MD simulation)
DNA suspension microchannel
flows
(DPD simulation)
Color Rendering – PHYSCIS
- Vision Science as a Basis for Optical Metrology-
We will perform vision experiments to examine:
Color discrimination
Tunable light source
Color fidelity
Measurement
Overall color quality Data
Computational Vision
Under illumination of models experiments
30 to 50 different light
spectra using CVEF.
Results Results
Use several hundred Correlation
calibrated color chips. Improvements
Validation
Standard
Contact: Yoshi Ohno, Optical Technology Division, Physics Lab, NIST
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