Transcript a study of raman spectroscopy

OPTICS, LASERS, AND MOLECULES:
A STUDY OF RAMAN SPECTROSCOPY
Stephen Carr, Mojin Chen, Brian
Delancy, Jason Elefant, Alice Huang,
Nate May, Avinash Moondra, John
Nappo, Nick Paggi, Sam Rosin, Marlee
Silverstein, Dan Zhang
Advisor: Dr. Robert Murawski
Assistant: Aaron Loether
What is Spectroscopy?
• Break light into constituent
wavelengths
• Study of interaction between light
and matter
Understanding Spectroscopy
• In order to understand
spectroscopy, we must first look at:
o Optics
o LASERs
Optics
• Optics: study of light
• Light: electromagnetic radiation
o
Wave-like properties
 Reflection
 Diffraction
 Refraction
o
Particle-like properties
 Quantization
Converging Lens
• Object focused through a convex
(converging) lens
• Curved shape focuses light to
single point
LASER
• Light
• Amplification by
• Stimulated
• Emission of
• Radiation
Lasers
• Highly controlled beam of light
• Emit monochromatic light with identical
wavelengths that are completely in phase
• High accuracy measurements
• Better suited for use in optical analyses
than other light sources
• Easily manipulated by optical devices, i.e.
lenses
Raman Effect
1928 C.V. Raman discovered
Raman effect
o Used heavily filtered sunlight
in place of a laser
o Observed the energy change
between the initial laser
energy and the emitted
energy
Raman Spectroscopy
• A light scattering technique in which
photons interact with a sample to
produce scattered radiation of varying
wavelengths
• Allows one to obtain vibrational
spectra of substances in aqueous
solution
• Measured in wavenumbers (cm-1)
Why is it Useful?
• Gives detailed information about
molecular structure
• Can be used to examine:
o Rotational
and vibrational states
of a system
o Number, strength, and identity of
chemical bonds
The Apparatus (Helium-Neon)
Helium-Neon Laser Setup
The Apparatus (Argon-Ion)
Argon-Ion Laser Setup
Our Project
Determine effectiveness of RS by:
o Analyzing
methanol, ethanol, and
fertilizer samples in varying
concentrations
o Testing for impurities and foreign
molecules in different samples of water
Data: Methanol
Data: Ethanol
Data: Ethanol Concentrations
Data: Fountain Water vs. SmartWater
Data: Fountain Water vs. SmartWater
Data: Fertilizer
Data: Pond Water & Fertilizer
Applications in Real Life
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Identify Molecules
Environmental Monitoring
Explosives/Contraband
Quality Control/Commercial Industry
Biochemistry/Medical Applications
Art Examination and Preservation
Electronics and Semiconductors
Acknowledgements
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Dr. Robert Murawski
Aaron Loether
Stephen Takacs
H Sudol
Drew University
Staff of NJGSS '10
References
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